How To Repair Briggs And Stratton Engines

I like to perform my own maintenance on my Briggs & Stratton engine and enjoy helping others do the same.

Before y'all shell out for an expensive repair to your Briggs & Stratton, read through this helpful guide to learning how to diagnose and gear up your lawn mower's potential compression release problems.

Alexas_Fotos, CC0-Past, via Pixabay

Is Your Briggs and Stratton Hard to Start?

Does the engine struggle to turn over, and it seems as though the starter must exist bad or the battery dead? Is it fourth dimension to pay big bucks for lawnmower repair? How will y'all go that lawn tractor to the repair shop?

Before you do anything too drastic, keep in heed that information technology may not be that serious of a problem. If this is an overhead valve (OHV) engine, and then it may be that you take just overlooked a basic maintenance procedure. Sometimes you lot have an like shooting fish in a barrel repair on your lawn tractor.

Well-nigh of the overhead valve engines have a compression release characteristic that allows for the starter to non accept to work hard to crank the engine. It'due south a slight raising, or bump, on the lobe of the camshaft. What it does is open the valve a little early to allow excess compression to bleed off. At speeds over 300 rpm, the tappet just sort of floats over this bump, and information technology has no effect on engine performance. But at starting speeds, it's essential, otherwise the starter just can't turn the engine over.

If the engine will plow over easily and hiccups, won't rev or make power, or just won't commencement, then you may be looking at a fuel supply problem.

This guide volition assistance you lot diagnose and prepare your hard-to-start Briggs & Stratton engine.

How to Diagnose Your Lawn Mower Engine's Problem

To diagnose this problem, you will need a voltmeter.

First, check the battery voltage by using the voltmeter on each battery terminal. You should take about 12 volts.

Next, bank check the voltage at the starter with the key in the kickoff position. Y'all may need a helper at this indicate, depending on the equipment. What you have to do is ensure that all safe features are activated but equally though y'all are starting the engine. With 1 lead from the voltmeter on the post, on the starter where the cable connects and the other leads to a good footing such as the engine block, there should be about the same voltage as there was at the bombardment. A drop of a volt isn't a concern. If all this checks out okay, then it's a reasonable diagnosis to suspect the pinch release.

Proper performance of the compression release requires proper valve lash adjustment. Adjusting the valves is a relatively simple project requiring only a few tools and once you learn how to do it, you should include it with your almanac maintenance program.

• Ratchet with extension and 3/8", 7/16" and 1/ii" sockets
• Feeler guess in .004" and .006"
• 3/8" wooden dowel or substitute
• Torx or Allen driver to fit lock screw

How to Set up a Compression Release Problem in Your Briggs & Stratton Engine

1. First, you need to admission the valve cover. This will be the argent cover on meridian of the engine head. It will have OHV stamped into it and is held on with four screws/bolts. These screws are unremarkably three/8" or vii/xvi" hex head and are removed using a socket and ratchet. There is a gasket betwixt the valve cover and head. If you are careful, you lot tin usually re-employ this. Then remove the spark plug.
2. Now with the cover off, y'all can run across the rockers, push rods, valve springs, and valve stems. The valves are the ones with the springs on them. If you turn the flywheel by manus, you will run into the valves move up and downwards and come across how the assembly works.
3. Notice the intake valve. This will be the one that the carburetor feeds fuel and air into. If y'all remove the pushrods, typically the intake valve will take an aluminum pushrod, while the frazzle valve has a steel pushrod.
4. Y'all will need to turn the flywheel clockwise until y'all see this valve open (move downwards) and and then close again. Once the intake valve closes, the piston will be headed to the summit of its travel, or Tiptop Dead Middle (TDC).
5. At this point, take the wooden dowel and insert it into the spark plug hole. You should feel the elevation of the piston.
6. Slowly turn the flywheel by hand while property the dowel against the piston, and y'all will experience the piston move. Exist careful doing this. If the dowel starts to become caught in a demark, back the piston up and remove the dowel. Yous just desire the dowel in the cylinder when the piston is at or near the peak of its travel.
7. With the piston at TDC, rock the flywheel back and forth to observe the highest spot of the piston travel using your dowel.
8. Discover a spot on the head that's easy to see, and marking the dowel where information technology lines up with that spot. Now remove the dowel and make another mark ane/iv" above the first marking.
9. The valve lash should be set with the piston at i/4" by TDC. What you are doing is making a guess to line upwards the piston travel with a reference point. Now put the dowel back in, and rotate the flywheel then that the piston is now ane/4" past TDC.
10. On the rockers, the stamped metal pieces that open up the valves, there volition be a nut and a lock screw within that nut. Usually this screw will exist a Torx head, only whatever it is, loosen it and so loosen the retaining nut. You volition detect the slack in the rockers, the amount of slack is what you are adjusting.
11. For the intake valve, take the .004" feeler guess and insert it between the valve stalk and rocker. So tighten the retaining nut until the feeler gauge will just barely slide in and out. It should be a snug fit, and the gauge should have some resistance when trying to pull it out.
12. Then tighten the lock screw back down. That valve is finished.
13. Repeat the feeler gauge process on the exhaust valve using the .006" gauge, and replace the valve comprehend.
14. If the gasket tore when you lot removed it or it isn't in the best of condition, you lot tin can either purchase a new gasket or do what nosotros practise in the shop and use PermaTex Ultra Black to re-seal the valve cover. We also use anti-seize on the valve cover screws. Both PermaTex and anti-seize are bachelor at whatsoever motorcar parts shop, as well as the tools required. (Notation: If you lot have a twin cylinder engine, you have to treat each cylinder separately. You have to bring each piston to its respective TDC to adjust each cylinder'due south valves.)
15. One time you have the valve encompass back on, you're set up to start the engine. Don't worry if it's still doing the same as before. It usually have a few tries to do this right if you've never adjusted valve lash. Only start over and effort information technology a couple more than times if necessary. If you can't get it right later several tries, you may have a unlike problem which will require further diagnosis.

Thank you for reading this, and I hope information technology is of some help. Several people have sent me letters request for further help in diagnosis. Only please sympathise, due to constraints within this blazon of forum, at that place is just no way for me to practise that here.

Briggs & Stratton Pinch Release Set

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This article is accurate and true to the all-time of the author'due south knowledge. Content is for advisory or entertainment purposes but and does not substitute for personal counsel or professional advice in business organization, financial, legal, or technical matters.

Dave Lovekin on June x, 2022:

Stock-still a compression blocked starter in 10 minutes. Cracking commodity, thank you for submitting.

Shayne Campbell on May 09, 2022:

It is a mutual problem too for the exhaust valve port to get hit, due to the cooling passages getting plugged with grass. This tin can cause the exhaust valve guide to slide out of the.passage and lock the valve up, causing the pushrod to bend. Fortunately if i is mechanically inclined, this is appx an $fourscore repair with oil, parts, and gaskets. To eliminate this problem in the future, I drill a hole in the side of the head where the frazzle valve guide is, and installed a loctited set screw into the valve guide, eliminating the possibility of whatsoever movement. I recommend the valve clearance adjustment annually, or as the no crank (high compression) issue resurfaces.

Doug Cutler from Temperance. Mich on August 14, 2022:

After working on these type engines I decided to do a hub. Did a search to run into what hubs were already here. Establish this one. May practice some other explaining why the 1/4" piston down and the carb. flooding problem.

You would remember the shops would know virtually these problems. I got one in to repair that had the additional problem of gas getting into the cylinder from the carb. needle non seating. That actress gas in the cyl. volition do the same every bit the decompression not working. I got the extra gas out and after jumping the battery it finally started. It was then starting easily but smoked badly. Turns out the the head gasket blew between the cyl. and push button rod cavity. Another common problem with these OHV engines. Changed the gasket adjusted the valves. Engine returned to previous trouble of not turning over. When it was starting hands and smoking badly the burned spot in the gasket was a built in pinch release. So this ways the compression release pin on the intake lob of the camshaft is not functioning. This is why when adjusting the valves on these engines, with a properly working decompression organization, the piston needs to be 1/iv" down to clear the pivot. Next is to take the engine off and apart to set up the camshaft decompression system.

James Rosen from Connecticut on Baronial 02, 2022:

Thank you for this clear write-upwardly. I just caused a Husqvarna tractor with a 20 HP Briggs Intek single cylinder motor that would non beginning easily. I found the frazzle at 0.010 and intake at 0.005. All looked like new when I pulled the valve encompass no sludge or varnish. I reset both to factory spec using process yous described and the motor now starts hands and runs smooth. Only issue left is it will run for about 10 minutes misfire 2-3 times echo this about 4-5 times then cease running. A look of two-3 minutes and it will start and run fine for some other 5-x minutes and the cycle repeats. I found the gray wire to the fuel cutoff solenoid partially melted to the motor heat shield simply nevertheless not the issue even afterward repair. The engine has 438 hour run time on the tractor hour meter. Could this be the electronic ignition starting to fail? I have an inductive timing light to bank check for spark during any misfire but is there whatsoever improve test that does non require waiting for the misfire to happen brusque of replace and see. Too the plug was black and wet when pulled to set up the valve lash. Is 438 hours on this engine considered a lot or should i wait many more with correct maintenance

James Rosen from Connecticut on August 01, 2022:

Give thanks you I take a 20 hp Intek unmarried cylinder Hsuqvarna tractor just caused as a clear it out of my garage find. I constitute the exhaust at .010 when I checked and intake at .005 438 hours on the meter guess valves where never adapted. Used described procedure and starts similar a champ. this was a great helpful postal service. last issue I have is after about 10 to fifteen minutes the motor starts to miss burn down 2 or 3 times in a row does this 4 or 5 times and so shortly dies. If I wait a minute or 2 information technology volition beginning right up and run with no problem for some other short period of fourth dimension. though I institute the consequence with the greyness lead to the fuel cut off solenoid partially melted to the motor heat shield only no luck. Could this be the ignition module. The ability to restart after a short cool downwards wait period seems to point there. I have an inductive timing light ( yes I run one-time State Rovers which require old school tools) but have non checked for no spark even so.

Is in that location any known issue with fuel pump or vapor lock on these motors.

is 430+ hours considered terminate of life by Briggs for this motor.

bktrider on July xiv, 2022:

Hi, had to annals only to postal service this comment: I have watched videos of this process and acquire all-time from watching, however, his commodity was one of the all-time that I accept read about any topic. Y'all have first-class writing skills and I really capeesh you posting this article. A friend of mine has a Snapper with a 7 hp briggs and it is difficult to starting time. I rebuild/cleaned the carburetor and it is still hard to start.....about 11 y/o mower, I volition accommodate her valves and hope this takes care of her problem; I too recollect briggs as existence an outstanding engine and promise this turns out to continue to be the instance.

Regards,

Brian

blmgtnman on May 27, 2022:

My rider has been then hard to get-go these last iv-v yrs. Information technology's like it has a dead battery every time I'd go out to try and showtime it. I knew the starter was good considering information technology turns over easily without the spark plug. I've purchased 3 bombardment'southward for this passenger and finally gave upwards two years agone subsequently a shop charged me several hundred and didn't become the engine to turn over like information technology normally should. I and so bought a cocky propelled toro to go along my lawn looking decent. My bad! I'm very embarrassed right now.

I came across your article and your tutorial worked exactly as you lot described! Now I feel then featherbrained for not knowing I should be adjusting the valves on my Craftsman B&S xviii.5 hp ohv intek engine every flavor. Because of yous and your article, I will perform this process offset thing every season!

And yes, I found I needed to make several attempts adjusting the valves, but I eventually succeeded! The engine now fires off immediately! I'thou not an engine person and rarely if e'er volition I attempt something similar this. I'm so glad I was fortunate enough to come up across your article! And if I may, my wife couldn't be happier that at 65 yrs old, I'm dorsum in the saddle again!

You Sir, truly are a gem and I wanted y'all to know! Many, many thanks!! Hope yous accept a wonderful day! Be well! Rick

Cardinal Fang on April 17, 2022:

I signed up hither merely to say 'thank you' for this great, user friendly tutorial! I just saved loading up a zero plow mower & lugging it into town, and then leaving it for x number of days and then having them tell me (once again!) that it's a 'weak bombardment'.

Information technology took me maybe an hour, one-half of that fourth dimension was just gathering tools & printing out the tutorial above. Offset hit of the key after doing this and it's purring like a rabid kitten on steroids. (Ok... so I need a beer.) Either fashion - information technology starts like a dream and my original plan for this weekend was to weld up a full size car battery tray... glad I took 1 final look online and found this page.

Thanks again!

johng34 on September 25, 2022:

Cheers!!!

This was exactly my problem, Briggs and Stratton xix.5hp. But died during a mowing. The key for me was the loftier compression clue. Put a new battery in it and it couldn't turn the engine over. Two issues needed correcting before it would start.

ane) Frazzle valve rocker arm had three/8in gap, due to it's mounting stud coming loose and backing out iii/8".

two) Intake push rod, aluminum, bent. Don't know how information technology got that way, could be the steel cap on the acme of the frazzle valve, when information technology vicious into the lesser of the OHV well stuck in the intake valve on the mode down.

Installed new rod, loctite'd the stud dorsum in, adjusted valves every bit described herein. Started right upwardly. Put Kano Kreen in gas and oil, made it sound MUCH better right away. Going to prevent the input valve from sticking, which may have caused the bent push rod. Only 160hr on this 4yr one-time John Deere, that I bought used.

Thank you AGAIN, I've no idea how much money y'all saved me!!!!!

PK Jones (author) on January 15, 2022:

Hi, I really tin can't do diagnostics in this format. I'chiliad not able to log in on a regular footing and this format just doesn't allow for it. I can straight you to some other post I've made at the following link:

https://detect.hubpages.com/living/Why-is-my-eng...

It sounds like y'all have a a crankcase full of gas or a bad sabbatical.

Chuck 1 on Jan 06, 2022:

My engine was difficult starting but once information technology started ran good for 10 mins. I plow upwardly the throttle and started off so it started smoking actually bad. Fulled the garage with heavy smoke. and then died. I did not try to start again. I took the valve cover off and information technology was full of oil and and air cleaner also had lots of oil. this is where I stopped. looking for answers to the trouble. One side of the valve cover had oil residue. What should I look for now????? i'm thinking the head gasket and adjust the valves. Anything else????

PK Jones (author) on September xiii, 2022:

The feeler approximate to be used is the flat style. The round one would be more difficult to concur in place when tightening.

The side valve engines do take a valve clearance procedure but it would be more I can explain in a short comment. Typically if at that place's a cam article of clothing issue in a side valve engine, complete disassembly is required and replacement of followers, cam or valves is needed. Or y'all may get away with TIG welding material onto the valve stem end and machining to shape, merely that'due south as well more than than I can explain here.

On the side valve engine, kickoff with pulling the heads and cleaning the carbon build up. Too, y'all may have another outcome than the compression release, that would require a expert fleck of back and forth and I tin can't practise that here. Thanks!

cwatersjr on September 07, 2022:

Is there a way to bank check the valves on a 16 hp twin II Not OHV engine that is doing the same symptons equally the orginal problem above. Starter will only tunr the engine partially. If you take the plugs out it spins freely. Any suggestions would exist great..

cwatersjr on September 07, 2022:

Is there an adjustment on the valves when the motor is OHV? I take a BS 16hp Twin 2 that is having this issue only is not OHV.

andrewharshbarger on September 04, 2022:

what type of feeler estimate should be used when doing this or does it thing

PK Jones (author) on August 31, 2022:

Hi, one time you have the piston ane/4 Inch past TDC, you lot adjust both valves at the aforementioned time, no need to move the piston once more. Now since this is a twin, yous have to fix the piston 1/4 Inch by TDC before adjusting on each individual cylinder. So y'all practise one cylinder, then rotate the engine for the other cylinder and adjust it.

c- stanfield on August 26, 2022:

practise you have to bring the piston to 1/four by td. to adjust the intake valve so plough the engine again to adjust the exhust. i have a xx hp. briggs vanguard twin cylinder. i adjusted them the other 24-hour interval and i made it worse. was my start time. at four-6 ths. just i adapted them at td. thanks for whatever assist.

PK Jones (writer) on December fourteen, 2022:

Robert is that the Offset part of the Family number or the Model number? If that's a Briggs engine, the model number is stamped into the valve cover or on the sheet metal.

Robert on December 13, 2022:

Any 1 know the valve lash on this model 2bu706 16hp ohv. I cant seem to observe it on the nautical chart. I appreciate the assistance. THANKS

PK Jones (author) on December 12, 2022:

You lot can change the spark timing slightly by changing the air gap of the coil to the flywheel. Tight to the flywheel gives you lot a piffling advance, further abroad from the flywheel retards the spark. On a stock engine, gaining that little advance improves operation. On well-nigh Briggs engines you can't dorsum the coil up far plenty to keep information technology from firing, but the spark may be tardily plenty to cause difficult starting and brand it run a little weak.

The position of the flywheel on the crankshaft is the primary timing. On a performance engine we will either use start keys to adjust advance or not even bother with a key and just suit it according to dyno results. The key is nothing more an alignment tool, information technology doesn't hold the flywheel in place, merely kickoff keys make adjustment easier.

Yous typically won't see whatever advantage to advancing the flywheel on a stock engine, but past tightening the gyre to the flywheel you may. The gains are small, but every piddling fleck helps.

billybob on Dec 12, 2022:

Ignition timing is keyed to the crankshaft and flywheel.

Robert on December 12, 2022:

When i ajust the coil to flywheel to.010 is this not the airgap ?

PK Jones (author) on December 11, 2022:

Robert, I'thousand agape I cannot do diagnosis on this site. But, if this is a Briggs Intek engine, and so use the link to the Briggs spec sheet, http://www.nnyparts.com/briggsspec.pdf, and check your model number confronting that chart. The reason for using the manufacturing plant adjustments is to foreclose excess vesture and ensure your valves are properly timed. Outside of the factory numbers, even by .001", will add wear to the cam and rockers besides equally reduce performance. At .002" lash, the valves are opening too early on and staying open too late, IF .002" lash is exterior of the Briggs specs.

This volition cause higher fuel usage as well every bit a loss of ability. On a 16hp engine you may not easily detect the divergence, nonetheless put it on a dyno and you're probably losing 1/2 to 3/iv hp, which in a small-scale engine is quite a bit. Likewise air-cooled engines are very dependent upon proper valve and ignition timing for cooling and the prevention of carbon build-up.

For maximum performance on a stock engine, arrange the valves to the tight side of the specification and adjust your ignition timing past making sure that the coil is no more the thickness of a dollar bill that'due south been folded three times. Past having the curl tight to the flywheel like that, you advance the spark by maybe a couple of degrees which improves the fuel burn.

Remember, the lash adjustments are to ensure the valves are opening and closing at the proper time on the cam lobes. Too loose on the valve that provides the compression release and you lot as well will either have no compression release or it volition exist reduced, causing unnecessary wear on the starter.

Robert on December 11, 2022:

I BOUGHT THIS ENGINE USED AND IT IS 16HP ohv. WHEN I PUT THE ENGINE ON THERE, I CHECKED THE VALVE LASH.IT HAD VERY LITTLE.I couldn't fifty-fifty get a .002 gage to slide between the rocker and the pistom was up correct.This engine is running expert.Should i merely it .004 and 006 what information technology calls for or leave it like it is? Kneed some assistance THANKS

PK Jones (author) on Dec 07, 2022:

Sorry BillyBladez, I didn't mean for it to sound similar y'all were Bob. Bob has used several different usernames to try and get posted and continues to try and brand insulting comments everyday. I was letting his posts without the name calling and insults through simply enough is enough. Skillful luck with your TroyBilt.

billybladez66 on December 07, 2022:

for the record pk, im non billy bob. I'thou non gonna argue with somebody whose info saved my salary and my dough. For whatever reason a slight adjustment to the formula was what it took for me. Had it not been for your posts, i would have been a sad sad pupy nigh my troybilt. You just keep doin what yous're doin and i'll be happy to read what your doing...thank you to ya!!!!

La Purisima Golf Grade on December 06, 2022:

Thank you to that. Pocket-size engine mechanic and was needing exact specs.. Cheers Sick postal service 2morow and report results!!!

PK Jones (author) on December 05, 2022:

Bob, you lot said, "You said in the stop you adjusted the valves at .008 and .005 . What else did you find incorrect ? Your saying that the engine was hard to turn over. The valve adjustments being out that niggling wont make the engine hard to turn over." and then you lot said, "Just for your data... .002 of an inch is less than a piece of paper. Not very much.

And so you are directly contradicting yourself. You can try to recover by changing your story but you lot actually need to accept that there is a proper procedure and that being precise matters. It'due south nigh likely that you are not being precise and therefore aren't really sure what your actual lash is.

This will be the last post of yours that appears on this page no matter how many dissimilar names you try to utilise. I take not allowed some of your other posts to appear considering of your tone and am afraid that you bear the distinction of being the start I've had to do this to. This is not a forum to argue, information technology'due south an data forum. If you would similar to adjust your valves however you like, experience gratis. Nonetheless Briggs has a particular method they feel should be used and they would tend to know best. I've explained why the valves are set the fashion they are set repeatedly and that's non my recommendation, information technology is how Briggs designed the engines.

Attend a few Briggs training classes, and experience costless to argue with them and try to convince their Engineers they don't know how their engines are put together. I've been attending mill small-scale engine training since the mid-eighties and have yet to find a reason to tell a manufacturer that they don't know how to adjust their valves.

billy bob on December 05, 2022:

Yes .002" would make a divergence if the adjustment was "out of specifications" similar for example .007" similar your saying. Im not maxim that though. What Im proverb is I tin can conform the valves at .004",.005",.006" or anything in betwixt .004" and .006" (which is a .002" divergence) and according to the manufacturer they say this is fine because these are the actual specs. their recommending. What your telling me is this .002" difference is not adequate. Tell me what you would gear up the valves at if the recommended specs. were between .004" and .006"

PK Jones (author) on December 05, 2022:

Remember about it like this. Equally the lobe on the cam turns and the lifter follows it, the lobe begins to lift the lifter. If your lash is also tight, the valve will exist opening early on on the lobe's travel. If information technology's loose, it will open up late on the contour.

From .004-.006" is the corporeality of lash required to open up the valve at the proper time on the lobe. Add .002" to the gap and the valve will open many degrees subsequently on the lobe than if it were at .006". The lobe has a very abrupt rise once y'all enter the ramp then fifty-fifty .002" will be a big change. From .004-.006" in this example starts the valve opening at the proper signal on the cam lobe.

Valve lash is an adjustment made to control the opening and endmost timing of the valves. The valves have to start to open and close within a narrow window on the cam'south profile. Almost people remember valve lash is set to command the total lift on the valve, merely it's non, even though lift is affected. Information technology'south all most the proper timing of the valves.

The manufacturer does say .002" makes a divergence, nourish any Briggs training school and they volition cover clearances repeatedly. .004-.006" is the acceptable range in this instance. .007" would be out of spec.

billy bob on December 05, 2022:

Your missing my indicate. If the manufacturer is giving me specifications like .004" .006" for the valve adjustments it means a minimum of .004 and a maximum of .006 . When I went to schoolhouse they told me there is a .002" difference between those 2 measurments. Why is the manufacturer proverb .002" wont brand a difference only your saying it will ?

PK Jones (author) on December 04, 2022:

.002" is plenty to make a divergence when you are adjusting valves. Prepare the intake lash at .002" when the engine likes .004" and well-nigh engines will start popping as the intake begins to open several degrees early.

Valve lash is most when the valve starts to open. Too loose and the valve opens late, too tight, the valve opens early on. This is why virtually people have to attempt several times earlier they get information technology correct. The reason yous plow the engine i/4" by TDC is because of the cam's profile. This is how Briggs designed the system, and how the valves on these types engines are adjusted. The slight rise in the contour that creates the pinch release does wear which will change the measurements, which is another reason why you lot adjust at 1/4" by TDC.

billy bob on December 04, 2022:

If .002" is going to make a difference why are the specifications between .004 and .006 ? These specs hateful your adjustments can be either .004 or .006 or anything in between. Which is a .002" divergence. This is why I fix mine at .005" It runs fine.

billy bob on Dec 04, 2022:

I retrieve your referring to .004 and .006 every bit existence the limits. .004 being the smallest and .006 being the largest setting. Like I said earlier... I adapted both valves at TDC to .005" (eye setting) and the followed your proceedure of turning the crank another 1/4 " past TDC and my original settings of .005" were the same. I found no difference.

PK Jones (author) on November 30, 2022:

.002" is enough to make a difference with the pinch release. Although setting the valves tight is preferable to loose for functioning issues. That said, not all OHV Briggs engines use the .004 and .006" specs, just about. I wrote this referring to Lawn Tractors specifically, which when having OHV Briggs engine, will have Intek engines 99% of the time and employ the .004-.006" lashes. If in doubtfulness, just refer to the Briggs chart at this link, http://www.nnyparts.com/briggsspec.pdf

billy bob on November 30, 2022:

Just for your data... .002 of an inch is less than a piece of paper. Not very much.

billy bob on November 30, 2022:

Yous said in the cease y'all adjusted the valves at .008 and .005 . What else did you find wrong ? Your proverb that the engine was hard to turn over. The valve adjustments existence out that lilliputian wont make the engine hard to plough over.

billybladez66 on Nov 27, 2022:

great post. Had to attempt it about 4 times before i finally made progress. In the end i wound up setting the exhaust at .008 instead of .006 and the intake i set up at .005 instead of .004. Later setting it this way my flywheel finally purred over squeamish and smooth without the assist of a jump start from the trusty F100. This is something i volition brand sure to go on on center on from at present on. Btw, on my troybilt (2002, 18 hp ovc) my exhaust valve was on top equally i faced the engine. I could tell because the exhaust pipage was attached at the tiptop, to the left of the valve, and then i assumed it to exist exhaust.

robare15 on November 19, 2022:

I had the same problem with my 16.v Hp Briggs engine.

The instructions hither are excellent and helped me solve the problem.

Yet, non before frying a starter motor.

I bought a new starter from dbelectrical.com ($43)and my tractor starts like new.

PK Jones (writer) on November 15, 2022:

My argument reflects that if one valve is completely open, then the other valve would be at the same position as it would be at TDC, pregnant information technology would be closed. Not that both valves are completely open. The inherent problem with using this method on Briggs engines is that the valve needs to exist in phase on the cam with the piston 1/4" past TDC. The method of adjusting valves with 1 fully open and adjusting the other valve is an old method used on many pushrod engines. You simply bring ane valve fully open, rock the crank dorsum and forth to find the loosest spot in the other valve's lash and so arrange. So repeat for the other valve. People have been using this method for decades on all sorts of engines, works pretty well for multi-cylinder engines when y'all don't have a book to tell you what cylinder corresponds to the other.

Frank on Nov xv, 2022:

This is what you've stated..."Having i valve completely open would accept the other at the aforementioned position." Its impossible to have both valves "completely" open. Unless theres a problem with the engine timing.

PK Jones (author) on November 08, 2022:

On the Briggs engines it's of import that you lot are across Meridian Dead Center and have the cam at the right position, which is the reason for going 1/4" past TDC. Using the method you mention, information technology would be difficult to know just where on the cam's contour y'all are. Having one valve completely open would take the other at the same position as at TDC so you would take to try to factor that in on each valve. Not that it couldn't work, just that the method in the commodity is the easiest manner and insures both valves are adjusted in phase.

kandk920 on November 08, 2022:

I accept also seen the valve lash adjusted by rotating the engine until one of the valves is completely open up, and then adjusting the lash on the valve that is closed, then repeating for the other valve. How is this different than the method you explained? Cheers

PK Jones (author) on October 17, 2022:

Hi, I can't exercise diagnostics on this site due to an agreement with some other site and the format of Hubpages actually doesn't allow well for information technology anyway. I volition tell you that the muffler glowing red is probably an overly lean status in the carburetor. Pull the spark plug and it'south probably gray and ashy. This would hateful yous have a carburetor that needs to exist rebuilt or replaced most likely, although an air leak could too cause this. There are a few other things that could be responsible simply that would require more than indepth diagnostics and I simply can't practice that hither. A carburetor result would be the most likely though.

If yous look at the intake manifold, you should exist able to see that it is in line with the intake valve, same for the exhaust valve and the exhaust manifold.

Bob on October sixteen, 2022:

Lamentable Nick. The intake is usually larger and frazzle is commonly smaller. The valve your describing on the top , is the intake.

Bob on October 16, 2022:

Hey Nick. The intake valve is ordinarily smaller and is in the block closest to the carburater. The exhaust valve is usually larger and in the cake closest to the muffler. When your request if the valve is closest to the meridian... Im gonna say your describing the intake valve.

nick on October 16, 2022:

How-do-you-do,New to this merely how do you know what valve is the intake and what valve is the exhaust?Is the valve closest to the top of the engine the intake or frazzle?

Thanks,Nick

Bob on October 16, 2022:

The muffler was glowing ruby-red on my old Briggs. Is this because the valves are out of adjustment ?

PK Jones (author) on September 17, 2022:

Thanks!

Jerel on September 17, 2022:

Hey there, I am a 15 yr veteran automotive technician with much experience in small gas engines. I had never ran into this i and the postal service helped a bunch.

dave on September 14, 2022:

Finally someone explains why it needs to be 1/4 by TDC.

I've always been curious.

PK Jones (writer) on September 12, 2022:

Hi, I can't really diagnose in this forum. If the engine is still hard to turn over so you may take another effect or fifty-fifty a worn cam. It would require a good bit of back and along to piece of work through it and I'g just not able to do that here. Thanks, PK.

Joe on September 12, 2022:

I adjusted the valves to .005" at TDC and and then checked the valves a 1/4" past TDC and there was no difference. The engine runs fine.

PK Jones (author) on September 12, 2022:

The valve stems shouldn't have any lateral movement, only up and down. If the valves are moving around side to side, then the guides are probably bad and head replacement is the all-time set up.

Jack th wack on September xi, 2022:

I will try your process. My initial problem was a cleaved push button rod. I put it all back together but it only ran for a infinitesimal. . . Roughly at that. One Q though; The valve shafts are grooved circumferencely. If the valve shaft is supposed to be locked in and move only within a certain range, is it possible that they tin can movement out of identify within a range of travel resulting in a gap so wide it can't be adjusted to spec.? The rocker arm and so flops around all over the place. More after I try the valve lash adj. Cheers for your help.

(Engine is a B&S model 310707, type0136-E1, 16HP Sears riding mower)

Nib on September 03, 2022:

Thanks for the tip. I replaced the head gasket on my craftsman lawn tractor, and later on information technology was difficult to start with the symptoms you described. Did the procedure, and it works like a champ. Hardest role was finding a feeler gauge. (Went to Walmart and Ace before going to an Auto parts shop).

PK Jones (writer) on August 31, 2022:

The way the camshaft is ground requires you to move the piston 1/4" by TDC so that you have an accurate lash. Adjusting at TDC on many Briggs engines volition give you likewise loose an aligning. Other makes, and some Briggs engines, can exist adjusted at TDC.

Joe on August 29, 2022:

Why do you have to continue to movement the piston another 1/4 of an inch past TDC ? Is this pocket-size motility going to make a difference ? Thanks

dakota on August 12, 2022:

My mower started doing this very exact thing this week. I went thru the unabridged electric from battery, sol and removing starter to exam it. Removed plug engine spun fine, replaced plug and as soon every bit it striking pinch it stopped. I tin leap it with a jump box information technology does fine. Tomorrow I will exercise the in a higher place to the letter I will let yous know. Thank you lot for your article. I experience sure its this.

Todd on July 30, 2022:

This is so true. Ive been building motors for my late model for 18 years and winning on good nights. Never thought my 14.five BS had a valve lash issue. Ive been starting information technology with a jumper box all f n year. 20min an it is back like new. I used a pencil for the TDC -1/4 worked great. Give thanks you lot saved me buying a passenger. Ane time a pelting out at all 3 tracks was worth it.

Mike E. on May 15, 2022:

cheers, Exactly the trouble .

PK Jones (author) on Apr 13, 2022:

Glad it helped yous. Remember to include valve aligning as an almanac maintenance detail.

J. Westward. on April 13, 2022:

Have had starting problems with my Sears riding mower for over two years. Concluding summer (2010) paid some small engine "good" $180, and he replaced the starter and battery. Same problem after he left.

Saw your commodity and tried it. Had never adapted valves on any type of engine. Took me a few tries to "become the feel" of what I was doing, but finally put the valve cover back on and gave information technology a try.

ENGINE STARTED IMMEDIATELY AND CONTINUES TO Do SO. Cheers very much for your valuable info.

Al on March 01, 2022:

That did it! Intake valve adjustment was .oo6" instead of .004", one time adjusted correctly information technology fabricated all the divergence in the world.

Thank you for posting!

Mark on January 29, 2022:

The engine on my Craftsman lawn tractor would just crank one time and non start. I was thinking information technology was the starter but constitute your article, followed the steps, and it started right up. Thank you lot.

PK Jones (author) on October 22, 2010:

Glad it was of some aid. Information technology's surprising the number of shops which fail to take hold of this one.

Marker on Oct 15, 2010:

Cheers a ton. Brought my Rider in twice to have the consequence looked at. They but kept telling me the battery was bad. It took me 15 minutes kickoff to stop and the engine starts and runs like a acme. Yee Ha!

PK Jones (author) on June 12, 2010:

Hi, yes, the engine needs to be at ane/four" by Top Dead Center (TDC). At TDC, the intake valve has simply closed and the frazzle has not begun to open up. The piston must be at 1/4" by TDC, so be certain to follow the instructions above for how to discover that spot.

D.J. on June xi, 2010:

does the piston need to be in same place for the intake and frazzle valve to be adj.?

PK Jones (author) on April eighteen, 2010:

Thank you! I'm glad it helped.

Pdemps on April 18, 2010:

Give thanks you, very helpful and relieve me $$. I capeesh it, best written article on the discipline I could find.

PK Jones (author) on April 03, 2010:

Thanks for reading information technology.

electricsky from Due north Georgia on Feb 27, 2010:

Thank yous for your article

Source: https://dengarden.com/landscaping/Hard-to-start-Briggs-and-Stratton-engine

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