No Compression? How to check and clean the Valves

No compression on my lawnmower. I figured it had to be either rings, cylinder head gasket or the valves, so I had to take it apart to find out.
Watch until after the frogs to see how she runs!!

[@thomascallaci1409]

Excellent details, great quality of focus for video, very good tips for the novice. Thank you.

[@davekennedy52]

Thanks Forever, so glad that you enjoyed it

[@candykennedy735]

Great video !!!!!!!! This is exactly the issue i had with my lawnmower! thanks so much for this super informative video !

[@COSMOSpml]

Dave - SUCCESS REPAIRING LAWN MOWER ! I had a bit of trouble getting the intake push rod in proper seated position, but all I had to do was return cylinder head to TDC and then the intake rod seated fine. Then I adjusedt the new intake and output valve gaps to specification (.005 inch), THANK YOU SO MUCH FOR YOUR VIDEO. I did have a lot of carbon and soot on the cylinder head and old valve channels, after cleaning with carb cleaner, reassembly, the lawn mower ran like new. Phil

[@davekennedy52]

Hi Philip, just read your previous post, sorry to get back to you late, had one of those days! Well done to you for sorting the problem. That push rod was missing the lobe on the cam and at TDC the lobe faces the push rod. I couldn't believe the crap that I had to clean off on my machine! So just think how much money you've saved by doing it yourself and the more you work on your machine the more you get to know how they work. Very satisfying to know that it runs like new after working on it

[@davekennedy52]

Thought you might like to see this kzbin.info/www/bejne/i2exlaR-fdGXi68

[@cynthiakey1258]

I learned a lot from your video. Thanks. Also loved the gift from your daughter.

[@davekennedy52]

Thank you Cynthia, we have about 20 frogs in our little pond, they get quite excited when they hear the noise, thanks for watching:)

[@vitaminsea5931]

Thank you! This is almost the exact same engine that the mower I am trying to fix has, so your video was very helpful. In my case the bad compression was caused by a blown head gasket. An $8 part versus $300 for a new mower, I'll take it!

[@davekennedy52]

Glad I could help! It also would have cost a whole lot more if you sent it in to a shop for repairs. So well done to you for getting it sorted yourself!

[@heavymechanic2]

Most things are fairly simple with a little instruction, I have a 6.25EX and its just keeps on going with a monthly oil change (2 hrs mowing every week)

[@davekennedy52]

That mower is going to last you a life time. I change my oil after about 50 hours. Just as important is keeping the air filter clean, but you probably know this. And yes, a little instruction and a dash of common sense!

[@pkennedy0219]

Hey man thanks for the video. Fixed my mower. Started on the first pull. People like you make you tube what it is. 😁👍🏼

[@davekennedy52]

Awesome! Such a satisfying feeling when it starts right up!

[@BillSikes.]

Thanks mate, I got a suitcase generator that ain't got no compression, your video has been a great help.. Good day sir

[@davekennedy52]

Thank you Strake, glad you enjoyed it

[@tomcox2579]

Wonderful video. Great teaching tool. And a wonderful dear daughter too!

[@davekennedy52]

Thank you Tom! And yes she is!

[@davidswindoll]

thanks for the instructional video. just the inspiration i needed to fix the old mower! love the wooden frog!

[@davekennedy52]

Thanks David glad you enjoyed it. Yes the frogs seem to love it, we have about 20 of them now, its quite a chorus

[@hadenhitz7010]

Are you using something else than water when you dip your brush in the jar?

[@davekennedy52]

Thats petrol in the jar, but now that you mention it, I think I could have used brake cleaner as well.

[@stevieg2755]

Thanks,followed your directions,started first pull

[@davekennedy52]

thanks Stevie, glad it helped!!

[@rjserra5535]

VERY IMPORTANT !! If you are going to turn the blade on your mower, disconnect the spark plug wire first and make sure that the wire and boot are well away from the spark plug. That will protect you from being injured because the mower cannot suddenly try to start while you are turning the blade.

[@davekennedy52]

Thanks RJ, always safety first!!

[@stevefindlay7155]

Nice! However the valves should be gapped per OEM specs👍

[@davekennedy52]

Thanks Steve, sorry I didn't show it on the video, but yes, I did gap them. There is a later video showing how I did it

[@DP-hy4vh]

0:52 - did you pull the wire off the plug before turning the blade? I wouldn't put my trust in just the kill switch in case there's something wrong with it. Pulling the wire off the plug guarantees it won't accidentally start.

[@davekennedy52]

Yes, you're right DP, looks like the spark plug wire could still be connected. Can't say for sure, usually I would have taken it off

[@reyreyna1068]

Good video Sir, Thanks 👍

[@davekennedy52]

You're welcome Rey, glad you enjoyed it

[@justintime5773]

Thank you for the frog at the end😂

[@davekennedy52]

a great gift from my daughter, the frogs get very talkative when I use it. They're still all doing well and love the new fountain that I've just put in the pond. Thanks for watching

[@livenfree]

Had a little difficulty finding right torque specs for head bolts. Eventually found 114 inch pounds. Did you just hand tighten?

[@davekennedy52]

I also had difficulty finding the correct spec so I just tightened by hand. Found them afterwards though and they were 140 inch pounds which is about 12 foot pounds. Didn't seem very much so I think the hand tighten was good enough

[@jw2par]

Excellent video great camera views

[@davekennedy52]

Thanks for the compliment JW!!

[@muzendataps7692]

Good job ps like the froggy 👤😋👌👍

[@davekennedy52]

thanks Muzenda, yes that noise usually starts them all talking

[@sagitario12ish]

Good job, in these lawn mower, is not necesary gapping the valves? Thanks.

[@davekennedy52]

Thanks Sagitario, I use my mower a lot in summer, so I check the gap at least twice a year.

[@michaellicavoli3921]

You should get together with Steve over cheap beer and a Barbie! Great video mate.

[@davekennedy52]

Thanks Michael:) sounds like a fine plan! I also enjoy his videos and subscribe

[@lenny38138]

Love the frog!

[@davekennedy52]

Thanks lenny, a gift from my thoughtful daughter, the frogs in the pond like it too and I always get a reply

[@Timo-Epis]

How often do you need to check the valves in lawnmowers?

[@davekennedy52]

Thanks Timo, I usually check it at the beginning of summer and then half way through summer. I cut a lot,, about 4 times a week.

[@Timo-Epis]

@@davekennedy52 I didnt check them for 4 years 😅

[@davekennedy52]

@@Timo-Epis if the gap is too big you can hear them clattering and you won't have compression, if its too small the starter rope is difficult to pull. I always say that if you haven't got a problem, don't touch it, it just complicates your life!!

[@Timo-Epis]

@@davekennedy52 Well when you hear it it's already too late tho!

[@davekennedy52]

@@Timo-Epis if you're concerned you should check it out, doesn't take long to do

[@MT-gv8ns]

Well done - maybe should have added a comment about resetting the valve clearances - a bit of wind noise - but all in all very well explained. Just Subscribed

[@davekennedy52]

Thanks for subscribing MT, appreciate it! Yes, pity about the wind, guess thats the downside of working outside. Will be making a separate video quite soon on the valve clearances

[@stevesmith6058]

When you reassemble lap the valves back in don’t assume that they’ll seal and you also need to torque the head bolts with a torque wrench

[@davekennedy52]

Good advice, thanks Steve

[@davehoban6675]

what the gap on the rockers ?

[@davekennedy52]

Dave the intake is ,005 and the exhaust is ,007. Check your specs though!

[@hp11208]

Hello from Connecticut 🇺🇸

[@davekennedy52]

Hello to you too

[@livenfree]

Great video! Solved my problem. Mine had carbon build up on the exhaust valve shaft/stem so that valve was stuck wide open. I sanded it with very fine sand paper. Took quite a bit of sanding to finally not stick anymore. Curious if certain types of motor oil would cause more or less carbon build up?

[@davekennedy52]

Thanks Michigander, glad it helped sort out your problem

[@jeffarmer4428]

Great job mate !!!!!!!

[@davekennedy52]

how did i miss your comment,? thank you:)

[@HotrodTodd81]

How did you adjust the valves

[@davekennedy52]

I can't believe that I didn't show that, sorry Todd. There's usually a locking nut and a adjusting nut. In this case a locking nut and an allan key adjuster.. Have a look at this video and you'll see how I set the valve gap. Apologies again. kzbin.info/www/bejne/pYiUn3qJacSmecU

[@davekennedy52]

Hi Todd thought you might want to watch this kzbin.info/www/bejne/i2exlaR-fdGXi68

[@xkabedaruhe2956]

Thanks for this very informative video. My lawnmower works fine at the time being, but at 17 years old one never knows what will fail next...

[@davekennedy52]

hang onto that mower xka,and treat it well, they don't make them anymore like they used to:)

[@lestergillis8171]

Most OHV engiines have SOLID LIFTERS. They must be adjusted once-in-a-while. Failure to do this will ultimately result in BURNT VALVES.

[@davekennedy52]

yes they do, and there's also hard starting, misfiring, compression issues,valve damage and cam damage. Best to check regularly

[@COSMOSpml]

Please share how you adjusted the intake and exhaust valve clearances. Are both specs for this Briggs and Stratton engine .005 ? Are both adjustments done with the cylinder head at top dead center position ?

[@davekennedy52]

sorry Phillip, should have showed it. Both inlet and exhaust are ,004 to ,006 so I do both at ,005. If the piston is at TDC then you can adjust both at this time. Or you can remove spark plug (for safety reasons) then turn engine until one valve is fully depressed, then gap the other valve. Then repeat until the second valve is fully depressed and gap the first one.

[@COSMOSpml]

@@davekennedy52 Hi Dave, thanks so much for the information. I really enjoyed your video.

[@davekennedy52]

@@COSMOSpml You're welcome Phillip, hoping to make a video quite soon on adjusting the valves, so stay tuned

[@COSMOSpml]

@@davekennedy52 Hi Dave, I went ahead after getting a specification PDF from Briggs and Stratton on setting valve clearance specs. I cleaned the head gasket and valves as you showed in your fine video. But now the bottom push rod does not want to reseat correctly - it goes all the way in without hitting any resistance, even when turning the engine blade to move the piston position. What might I have done wrong to screw up seating for the bottom push rod ? Phil

[@tonycordero955]

What was used to clean off the carbon

[@davekennedy52]

Hi Tony, I just used petrol along with a fine soft wire brush and then a tooth brush. Thanks for watching!

[@BushcraftingBogan]

Did you set the valve adjustment on the rockers?

[@davekennedy52]

Thanks Fisty, yes I did, I have another video which shows how to do it. this machine is ,005 on the intake and if I remember correctly ,007 on the exhaust. The exhaust valve clearance is usually more than the intake

[@leslieking3974]

I shall try mine tonight or tomorrow to clean up the valve, spring whatever inside. I got 45 psi half of normal running. No wonder no start.

[@davekennedy52]

I'm sure it'll make a huge difference

[@ncrdisabled]

I love the frog!!!

[@davekennedy52]

Yes, its quite a novel idea, certainly starts the frogs chatting!!:)

[@michaellast1385]

I have 4 push mowers, all work excellent one is new, all of them can easily have the blades turned by hand, seems normal to me.

[@davekennedy52]

Release the brake, take out the spark plug and then turn the blade. That is what no compression feels like. On my machine, the plug was in and the air was escaping past the valve, so no compression. thanks for watching Michael

[@lestergillis8171]

@@davekennedy52 When was the last time you adjust the valve clearances on it ? (Just asking for a friend.)

[@davekennedy52]

@@lestergillis8171 I cut a lot, 3-4 times a week, so I check them every 4 months or so, and change my oil at the same time. A guide to follow is every 50 hours

[@healthyamerican]

i have a one year old mower that was low on oil and slightly locked up, but i got it unlocked easily. the valves are not moving at all. when i pull the rope there is no compression, only a ticking sound. i dont know what im doing but im learning as i go. is there any hope for this mower? ty

[@davekennedy52]

For sure Ty, there's always hope. From excess heat I think your valves are stuck. So remove the head carefully so as not to damage the gasket. Then remove the valve springs. You might have to tap out the valves so use a piece of wood for that. Then get 600-800 fine sandpaper and sand the valve stem. Then clean up the valve seat area like I did. When putting it back together use a lot of oil and also try and get the oil into the sides of the piston as well because that will be dry as well. Good luck and let me know how it goes

[@healthyamerican]

@@davekennedy52 k..i will give it a try...ty

[@DanMcDonald-do5ho]

1st thing I do is pull out the Spark plug before doing anything near the Blade, good time to clean it as well. as other metioned at least unplug it.

[@davekennedy52]

Thanks Dan, yes, you're right that was a bit irresponsible especially because it was a "how to" video, thanks for the advice and thanks for watching

[@notjoecheez1]

Thank you for this info. Helped me out tremendously. Did you torque the head bolts to a certain torque? If so, what was the torque spec? I have a pressure washer that has this same issue. It’s 140cc. So I’m going to have to adjust the valves once they are loose to a certain spec and torque the head bolts to a certain spec. Just wondering what specs u used

[@davekennedy52]

I didn't have the exact specs so I just used a reasonable amount of firm pressure to tighten them. If you're going to use a torque wrench, I'm guessing not more than 18 to 20 ft/lbs but rather google it

[@lestergillis8171]

Failure to adjust valve clearances will ultimately cause burnt valves & loss of compression.

[@davekennedy52]

Quite right! However most people don't and then its too late!

[@andyhamilton8940]

George Harrison’s mower repair😂

[@davekennedy52]

and sometimes I wish I had "8 days a week" to get everything done!

[@timtweet8149]

Need to scrape and clean under the deck aka bonnet

[@davekennedy52]

Thanks Tim, I agree it looks really bad. Surprising because I usually clean it after cutting, must have been an off day

[@timtweet8149]

It's the military in me. We called it, Attention to Detail.! The other is safety first! Always disconnect the spark plug or better remove it while working on any moving parts like the blade.

[@davekennedy52]

@@timtweet8149 Quite right, of course, thanks Sarge!!

[@lestergillis8171]

With as much carbon residue as you had , You should suspect bad gasoline. Normal 86-87 gasoline ought NOT cause so much carbon build up unless the carburetor is running too rich...

[@davekennedy52]

I' always use 95 unleaded as recommended but these days it has 5% ethanol. The amount of carbon build up really surprised me! Could be too rich as you suggest, so thanks for the tip

[@weechitamex]

davekennedy52 : thank you again sir .

[@davekennedy52]

you're very welcome, thanks for watching