How to Fix This Briggs And Stratton Engine With No Compression [EX 550]

In this video I'll give you a couple of reasons why your EX550 Briggs engine doesn't have any compression. It could be a stuck valve, or the head gasket could be blown. There are still other reasons why your mower might not have compression, but I cover these two in the video.
Heres some valuable Info for your project:
Head Gasket P/N: 799586
Rocker Cover Gasket: 591255/ 595341/ 84006580
Specs for 9P Series Engine
Head: 140 in/ lb
Rocker Cover: 50 in/ lb
Intake clearance .005- .007
Exhaust clearance: .007- .009
Oil Capacity: 15 oz
Sp Plug Gap .020

[@clevisforharrow]

nice clear instructions. I have renewed hope for my 15" wheeled trimmer. You've made me confident to try this. It has a Briggs and Stratton engine. TKS

[@JLPicard440]

Awesome, you're welcome. I hope it works out good for you.. 😀

[@ianhegan-rumohr791]

Thanks, was looking for a straight to it video to get the job done. Good work!

[@JLPicard440]

Thank you! You're welcome..

[@petelugo2681]

Outstanding video. Thanks for taking the time to make it and help beginners like me.

[@JLPicard440]

Glad to help! You're welcome..

[@garymanfredo7526]

Thank you so much. I now have the courage to try and fix mine.

[@JLPicard440]

Excellent! I'm glad I could help... 😀

[@weschaffin]

very well produced. Thanks I plan to tackle this project soon with a carb clean and rebuild

[@JLPicard440]

You're welcome! Thanks for the great feedback, so glad I could help.. 😊

[@mover8012]

Great video! You make it look easy, so I'll dig into this tomorrow.

[@JLPicard440]

Excellent! Hope you can get it going again.... 😀

[@mindtekzone]

Excellent video and presentation... thanks!

[@JLPicard440]

You are welcome!

[@johnnyeriksson2408]

Thank you for very good advice. I follow you from today 😀🙏

[@JLPicard440]

You’re welcome 😊. TYSM for the great feedback and follow... 😊

[@itistao]

Excellent teacher!

[@JLPicard440]

Wow, thank you!

[@jciamretired9767]

Good video and informative. Thank you

[@JLPicard440]

Glad it was helpful!.. You're welcome.. 😊😊

[@joerosburns5639]

Thanks for the video! BTW: Love the mixed SAE and Metric Head Hardware!

[@JLPicard440]

Thanks for the great feedback!...

[@ronaldgentry9923]

They are actually 7mm and 8 mm, but 8mm and 5/16 are so close to the same size that a 5/16 socket fits a 8mm bolt

[@christopherweaver2220]

This is excellent!

[@JLPicard440]

Thank you!.. 😊

[@robertgiller4246]

Great video. Thanks. B&S engines sure look alot different than the old flat or L head engines. I’ve worked on the plastic carbs before to remove a piece of dirt. Plastic is one way I guess to deal with ethanol.

[@JLPicard440]

Yes exactly. The old flat head engines were before my time, but I've seen them. When I first saw the plastic carbs I thought they were junk, but over time I can see that they are actually better than the metal ones since they'll clean up much easier when someone leaves gas in them for an extended period. The gas tank too....

[@WhitSide]

Exactly what i needed

[@JLPicard440]

Excellent! So glad to help...

[@williamwaters4506]

Very informative.

[@JLPicard440]

Excellent! Thanks for the feedback... 😊

[@attheendoftheday8969]

Edit: Problem Solved! There was a nut that lodged itself in the intake valve! Bent it pretty good so I have new parts and gaskets coming in tomorrow. Finally after 3 wks of troubleshooting 😅. Great all around vid! Currently working on a 110cc Taotao atv with no compression at all, just like what you had. Tried tapping the rockers and tried soaking overnight but no change. Might be the gasket!

[@JLPicard440]

Wow! Where in the world did the nut come from in the 1st place..? Good job troubleshooting. I hope the nut didn't damage the head if it was bad enough to bend the valve.

[@attheendoftheday8969]

@@JLPicard440 I recently bought it for cheap on Marketplace, thought it needed carb cleaning. The nut holds the air filter on from the inside which is a design flaw. The good thing is it didn't go past the valve, it just made it stay partially open. The cyl and head were still good. Can't wait to hear it purr today!!

[@attheendoftheday8969]

It runs like a beast now 😃 What a thrill it was to hear it start right up. Your vid got me on the right track, thank you!!

[@JLPicard440]

@@attheendoftheday8969 That's awesome! Yes I buy mowers from marketplace whenever they pop up! Which lately hasn't been much.. 😒😒

[@attheendoftheday8969]

@@JLPicard440 everybody might be learning how to fix them now from watching your Diy vids. A catch 22! Lol

[@holdemNE1]

Nice fix

[@JLPicard440]

Thank u!

[@somphonet]

thank you bose

[@JLPicard440]

You're welcome!

[@tipsclubs01]

Thanks for the Great Video. I have the same problem with my B&S engine off of a Pressure Washer. I will check mine out and see if It will work.

[@JLPicard440]

Hopefully that's the issue.... 😀

[@tipsclubs01]

It's a place to start, it could work. Also have another engine like this one, but need to know what the Torque is for the FLYWHEEL I had to make a tool to hold the flywheel so I could torque it, but don't know the torque limits. Thanks. @@JLPicard440

[@JLPicard440]

Personally I just use an impact and tighten the flywheel with that. You just have to know where to stop.. (I know, not very scientific!). If you google your engine and input flywheel torque specs you'll probably get some idea of where that is actually supposed to be... 😀

[@tipsclubs01]

Thank You, I'll Google it. Thanks for the info. @@JLPicard440

[@JLPicard440]

You're welcome..

[@ronnieicard]

I was taught years ago to run the piston up to the top before scraping the gasket off the head. That way debris couldn't fall down into the piston hole. Also, clean the carbon off the top of the piston and valves while you're at it, as well.

[@JLPicard440]

Great ideas! Thanks for the tips... 😊

[@eostrike]

Good job on the repair. Chances are the compression was in the low side was due to the compression release valve. If you spun the engine with a drill and the cover off you would have had a better result. Just curious why you did not perform a leak down to make sure it was the head gasket? Thanks for putting this together.

[@JLPicard440]

HI, yes I'm not 100% sure this engine has the compression release, but I'm pretty sure it does. I've tested other engines of the same make and model and had the same compression result... Thanks for the great feedback... 😀

[@bluzzjazz]

Tackling a run for a few seconds and then dies problem. Cleaned the spark plug and it will now run but unevenly and with about 30% of full power. Thanks for posting, hope it's just a carb cleaning issue. It was strange that I was almost finished cutting the yard and it just died with plenty of gas still in the tank.

[@JLPicard440]

It very well could be... if you're going to pull the carb, I usually will dump the fuel from the gas tank into a clear jar so I can see if it's contaminated with water or trash... Then I'll flush out the tank with a water hose and let it dry completely. Before you go through all that, do a compression test if you have a tester. You never know, it might reveal a problem.

[@bluzzjazz]

@@JLPicard440 Thanks for the response. Took the carb apart and cleaned it thoroughly. There was a little bit of sediment in the bowl but not horrible. I have a feeling one of the jet ports was clogged. I ran wire through it and rinsed everything real good with cleaner. I put it back together and it started first pull with full power! Having never attempted this before, the video was very helpful.

[@JLPicard440]

@@bluzzjazz That's excellent! Did you flush the gas tank out? There might have been something in there that wound up in the carburetor..

[@bluzzjazz]

@@JLPicard440 I did not because it looked very clean when I shined a light into it. Probably not a bad idea though. I only have about a quarter tank in it. I'm just thrilled it actually started after I put it back together!!

[@JLPicard440]

@@bluzzjazz Awesome! Make sure to save that 1/4 tank into a glass jar or something incase it looks fine!.. That's worth a pretty penny.... 😂

[@bluesingmusic3443]

Thank you my grandson bought a used mower, with a written 30 day guarantee. They guy it was "serviced & ready to go". After my grandson started the mower, it seized up. I called the guy. He started screaming' he told us to change the oil, etc. It also had gas dripping from the "totally rebuilt carburator". Told my grandson call the guy, tell him to keep the money ($40) but come get the mower. Well the guy was saying he'd come by & give us the money back, pickup the mower, etc. He did neither. LOL Anyway my grandson found a mower exactly like the one in the video. No compression. This video, lets me know, we can fix it for $15. I appreciate your detailed, easy to understand instructions. (the mower was a curbside find). He's happy, he can make some money, with what little of summer is left. He watched this like a hawk. Now I've got to find a Torque wrench. Sorry for the long comment, but I've been steaming about the last mower.(The guy, is here "To help the kids" should've been my first warning flag.)

[@JLPicard440]

Wow.. first it's just sad that the guy you bought it from acted like that. There's no guarantee that the curbside mower will have exactly the same problem, but I hope it does for you. If you have a harbor freight in your area they'll have a torque wrench fairly cheap.. just make sure it can do in. lbs instead of ft. lbs. also be cautious about who you get the head gasket from. I had to get two of them because the first person didn't package it correctly and it came having been folded through the mail and was ruined. Those don't like being folded. If a local parts store has one, thats probably your best bet since you can see it before buying. I hope you get it going.. Let me know if you have questions.. happy to help.

[@gargar209]

Great video. Quick question was the mower showing any visual or audio ques that the gasket was bad? Leaking oil or wooshing sounds

[@JLPicard440]

HI, not for me it didn't. But those symptoms could show up when a gasket is ready to fail... 😀

[@jackrifle5068]

I had a similar problem with my qaumtum xts 60, so I bypass it by jamming a piece of wood in and keeping the valve open.

[@JLPicard440]

Excellent! Thanks for the idea and the great feedback... 😀

[@daphnekite578]

Can you tell me where the valves are on a quantum engine on briggs and Stratton

[@JLPicard440]

HI, I'd have to see it... You can upload a picture to my take a bath productions FB page if you have access to that.

[@knighthawk86855]

I was working on a new customer's mower, it's 1 year old, the husband said he had hit a rock, and the blade shattered, and he was right, he showed it to me, and it shattered, never saw that before, but he replaced it correctly, it didn't shear the flywheel key, but getting to the point, it would not start, so did a carb clean, it wants to start, but noticed oil under the front of the engine, it almost starts, but sure enough blown head gasket, so we are waiting for the head gasket.

[@JLPicard440]

I've never seen a shattered blade either! They will bend up like a pretzel, but not shatter... I'm quite surprised that it didn't bend the crankshaft. If you get a shake once you get it running again, that could be the culprit...

[@knighthawk86855]

@@JLPicard440 yeah, I will take pictures, and share on my channel, but yes I will go over it.

[@abbieabbie6818]

If my push mower is pushing oil out the filter , What you think the problem is ? Start this after someone change the blades.

[@JLPicard440]

Possibly to much oil in the crank case...

[@rickeykeeton4770]

Maybe they tilted it the wrong way while changing the blade.

[@superiorpeninsula]

Question: 50 is a 'little low'. What do you think is causing the lower compression? Rings?

[@JLPicard440]

Could be.. Some of the small engines have a compression release on the camshaft. I don't know if this particular one does or not without seeing the camshaft. I have another one here I'm working on with the same engine, if I think about it I'll do a compression test on it just to see if I get a similar result and get back to you. If you don't hear from me by tomorrow morning remind me because I forgot!.. 😂

[@JLPicard440]

Update: I checked my other mower. Same engine/ cold. Had the same result around 50 psi. So that engine may have the compression relief... Once the engine gets up to speed, the compression goes up to normal. Hope that helps. Thanks.

[@superiorpeninsula]

@@JLPicard440 So, I bought a compression tester from Harbor Freight. I check 3 saws I have...all said 30 lbs. 🧐 So, I go check my running saw that's kind of new...30-40 lbs. I check my lawn mower (that runs fine)...30 lbs. Fed up...I go get a different tester. Same thing. 😒 Am I going crazy?? My lawn mower and saw shouldn't run at 30...right?? What are the odds of 5 pieces of equipment all having 30 psi?? I even checked my car...and although it was higher...it was reading like 130... and it's a newer rebuilt engine. 🧐

[@JLPicard440]

Yea 130 on the car is about 9:1 compression, which unless it's a performance car should be about right. 30 does seem a bit low, even mine had 50 which I think is due to a compression relief, but that a theory on that particular model.. Are you sure there's no leaks on the tester?

[@charritolopez8223]

These machines do have compression release they won't go over 45-50 I have had a couple that read 20 but for that same reason Compression release

[@daphnekite578]

Me again, I’m 76 so can’t afford mechanic. My problem was I ran out of oil when using self propelled mower it popped then stopped. I’ve cleaned carburettor and tried starting it with new spark plug and filter out but just nothing happens. Seems no compression as blades turn very easily . Do you have any suggestions on what may be the cause . Mechanics here charge $80 plus get an hour!

[@JLPicard440]

If it ran out of oil and then made a loud popping sound did it throw a rod? Take out the spark plug and use a bungie cord to tie the stop handle back so it'll release the engine brake. Then if you can pull the rope slowly with a long screwdriver in the spark plug hole. You should feel the piston coming up and then going back down. IF you don't feel anything moving in there then the engine is toast... ☹️

[@daphnekite578]

@@JLPicard440 Thank you. Does that still apply regarding the bungee cord if I have a self propelled mower. It Goes for ward when I lift handle? Sorry to sound thick! I’ll take a picture and see if I can send on Facebook

[@daphnekite578]

@@JLPicard440 yes I can feel the rod. I opened up where the valves are and the bottom one doesn’t look central through the spring. Is there anything I can do ?

[@JLPicard440]

@@daphnekite578 I'd have to see that... do you have access to FB? You can upload a picture on my take a bath productions page there..

[@JLPicard440]

HI, most mowers have a handle that you have to pull down to get the mower started... Not the one for the self propelled. It's just so you can turn the engine easily.. Don't try that without removing the spark plug in case the engine starts on you! That would be dangerous..

[@marshallborder9089]

👍

[@JLPicard440]

Thank u!

[@lccurtis6548]

Why do you suppose you only had 50psi when Briggs says 100psi? Rings? Valve seats? Could you have checked those while it was apart?

[@JLPicard440]

You can't really check rings without taking the crank case apart and removing the piston... Sometimes when the engine is cold, you'll get a different reading. I should recheck it when it's hot to see if it's better. That mower always ran good before the head gasket went out, so it wasn't worth that much trouble for me.. But I agree, I thought it was a little low.

[@jthoresen]

@@JLPicard440 I would say your compression was fine (greater than 50psi) the long hose on the compression tester probably gave you a false (lower) reading

[@JLPicard440]

@@jthoresen Good point... hadn't thought of that.. Thanks for the tip.

[@ceejay6882]

@@JLPicard440 Tip the mower back and squirt some oil into the spark plug hole in a circular direction (I use a syringe with an L shaped tube on the end). If your cold compression figure goes up a fair bit, it's the rings. I try to syringe most of the oil out after testing to make the next startup less smokey.

[@JLPicard440]

@@ceejay6882 Awesome! Thanks for the tip.. 😀... I'll put that in my bag of tricks..

[@fritzsnickerz855]

Torque specs in nm would be awesome

[@fritzsnickerz855]

clearance on the rod and crank "bearings" clearance and maybe partsnumber for new crank ,lower case halve .camshaft. piston and piston ring and rod and wrist pin and sizes and ring gap thanks dear community

[@JLPicard440]

Just google a conversion from in-lb to nm.. thanks.

[@JLPicard440]

You can easily look that up.. thanks.

[@chucksmoko5348]

Funny how Briggs had about twice as many head bolts for years and we rarely had issues. That mower looks somewhat new and has a head gasket issue? Look at the distance between bolts; that’s pretty far based on what worked well for longer than I’ve been alive.

[@JLPicard440]

I think that mower is a 2015 or something like that... Yea I don't see head gasket problems very much, but occasionally it can happen.

[@hodgemoll4452]

💯 Promo-SM!!

[@JLPicard440]

Had to look that up.. not sure exactly what that is..