Great video, even an 79 year old like myself could understand. I didn't know where or how to adjust the valve lash until your video. Thanks a bunch. Everett

This video was a life saver. I had this exact problem with my craftsman snowblower and following your procedure I was able to fix it. Now my blower starts up strong and actual blows slushy snow without any problem. Thanks again!!

You’re a skilled mechanic and these videos are all very well shot. Nice explanations!!

Great videos Donny. I have learned a lot by watching.Never too late to learn even at 71 years old.Keep up the good work.

Great video Dony, you have the most calming voice to listen to. I can listen to your videos all day long. Cheers

@donyboy73

7 жыл бұрын

thanks lol

Dude, many thanks for this video, it has just saved an old 7hp B & S from being scrapped! Keep up the good work!

@donyboy73

10 жыл бұрын

you're welcome man, make sure you are subbed

Great video Don. It helped me diagnose a valve clearance issue on a craftsman lawnmower mower. The mower now runs! Thanks again.

@donyboy73

3 жыл бұрын

Right on

Thank You. Not only for your quick responses to my questions but for everything you have taught me.

I found a free snowblower that had 80psi compression. I shaved the valve to spec and it was 150 psi after! Runs great now. This video explains the issue great.

Thank you you give me the information I needed I'm a mechanic myself and I just needed to look to see where the timing marks were and I do appreciate it god bless you and thank you very much keep on truckin brother I am Charles out Farland Albert Farland

Thanks Donyboy. I love your videos and small engine repair.

Thank you soooo much for this vid!! You guided me enough to figure out what was wrong with my snowblower and I was able to fix it. Got a storm coming tomorrow too and it wouldn't stay running even after putting in a new carb.

Did just this on my Tecumseh 5 HP rebuild...even with 'new' valves I had to grind (shorten) the valve to obtain clearance. Compression is good!

great video as usual ,, keep up the awesome work that you do,,, your very helpful my friend..

@donyboy73

7 жыл бұрын

thanks

Thank you for the video. I own a 8hp Tecumseh and I had a red hot exhaust at the end of last season, I rebuilt the carb but it was still running very lean. I had to grind 40 thou off the exhaust valve stem. I cleaned all the carbon off the piston and valves and changed the head gasket and intake gasket. The exhaust valve is seating properly now. I picked up a valve spring compressor and feeler gauges at Napa.

@donyboy73

8 жыл бұрын

+davidbrennan5 thanks for watching

One thing you mite want to add is make sure your not on valve over lap. Just because your piston is all the way up. Don't mean your on compression stroke. The way I was taught - is when the intake valve is fully open- measure exhaust. When exhaust is fully open- measure intake. Makes simple.

@joej.4170

7 жыл бұрын

EXACTLY. if its at T.D.C. its not always on the compression stroke. If you dont have the piston the correct way, you will get innacurate readings. Also, Briggs recommends that the piston be .25" below the cylinder when checking valve clearance.

@mentalbreak4653

2 жыл бұрын

If both valves are closed your on the compression stroke with the eng apart there both closed so really don’t matter

Thanks Don.I've been doing a lot of research on how to adjust non-overhead valve engines for the past few hours.Now I think it's basically the same for adjusting 18 h.p. Briggs opposed engine.Good info on the part about spinning the valve for wear.

@donyboy73

9 жыл бұрын

DesertDigger1 yes same procedure

@oracionysanidad9373

8 жыл бұрын

how to fix a small lawnmower if no compression and valves seems coming out and stuck

Thank you for posting this I really appreciate it.

Great video donny I've always wondered how to do that

Thanks for the demo. Very helpful.

I had to watch your video again thanks for sharing your video

My well used Murray mower, with the B/S 16.5 HP I/C engine, pumps oil into the valve cover through a galley located just under the intake pushrod. This oil is milky as it is being pumped but allowed to set for 15 minutes goes back to its normal color and consistency. It looks to be full of small air bubbles. I removed the head and found the gasket to be intact, no indication of a leak on the block or the head or the gasket. I removed the breather valve assembly (the reed valve as well as all else) and found it to be in good condition also. Very clean.This all started with the engine being hard to turn over even with a fully charged good battery. I reset the valves and this helped to some degree. It then began again to be hard to turn over. I then removed the valve cover and found it to be 1/4 full of oil. The motor does start with 3-4 tries, it runs good and idles as it should. It does not smoke as it is running but will on occasion emit a large puff of grayish white smoke and then the smoke is gone... The oil consumption is not excessive. If you might have an idea as to what causes this issue I would appreciate your advice. Thank you, ........Tom PS...I enjoy and appreciate your videos. You speak clearly and slowly enough to be properly understood. Thanks again......Tom Modify message

@dagrote1

8 жыл бұрын

+Thomas Huckaby What a baffling set of symptoms! I'd be interested to know if you figured out the problem. Worn rings, maybe?

All your videos are exellent'

Smashing tutorial :-) All the power of the engine just vanishing down the exhaust, and distroying the mixture as well. No wonder it wasnt happy.

Great video! All you videos are great. Is it possible that you could show how you take the valve out and the procedure for putting it back in? Thank you and keep up the great work!

love the great videos and detail, keep up the great work

@donyboy73

8 жыл бұрын

thanks

@charritolopez8223

3 жыл бұрын

@@donyboy73 do you have any videos on how to do this in an opposed twin cylinder Briggs and Stratton or is there something around youtube I've searched and have come up empty hsnded thanks for all your helpful informative videos may you and your business be blessed at all times in JESUS name

Nicely done. Thank you.

thanks for watching steve

Nicely done as always!!!!

thanks for sharing

excellent video!

Love your videos, I have learned a lot. There seems to be much confusion all over the internet regarding the valve clearances of Tec. L head engines. Some say like yourself, .008 in. / .012. ex. and some say it's .008 min. for BOTH valves and .012 max. for BOTH valves. Different years and versions of Tecumseh manuals have kind of confusing information. I have a 1978 Ariens 7/24 that backfires out of the muffler when working hard and quits. After it cools it runs good again untill you work it hard again. My exhaust valve clearance is about .006 or .007 I'm thinking it get less when good and hot and causing this problem. I don't want to remove too much material though.

@DanielHeasley

4 жыл бұрын

Yes! That is the question I'm trying to figure out. I believe it looks as if it's just a minimum of, in my case a LAV35 L head, .04 min and .08 max for both valves. But it sure would be great to be 100% certain on this.

Very helpful, thank you!

very great videos!

Good job... well done

Would of been nice to see how you ground the valve stem to the proper clearance and explained why the problem accrued. Why did it happen, I still don't know . . .thank you I fixed this same problem on a garage sale find, all I used was a pedestal grinder and a 10 buck digital caliper. I find the best grinding results accrue when you use the side of the grinding wheel since most of the time that part of the wheel has not been abused and will run truer. With nimble fingers and a 2 degree rake I gently rotate the stem against the side of the wheel, this will produce a crown in the center of the valve stem. I find this is much easier to controls then a flat grind, this way when you get close you can stone off 1 or 2 thousands with little effort for the final fit. Thank you for your teachings donyboy73 . . .we all need to spread our knowledge ;)

@JeffinTD

3 жыл бұрын

FWIW the valve clearance likely gradually reduced as the face of the valve, and the valve seat wore over time.

thank you!

Thank you for this video, very helpful. When you took the exhaust valve out to grind the stem, were there clues which indicated that the valve face did not need to be ground, or even lapped in?

Thanks 🙏 for sharing.

Don, I'd would love to see a video on guide replacement and seat and valve cutting. Thx

Well Donyboy, looks like this is my next lil project. My generator has that annoying lil "poof poof" backfires in an otherwise perfect tuned machine. Kinda betting the exhaust valve is spinning like the one you show in this vid. Wish me luck here.. and as always young man,,,, thanks for the vid.

Before Tecumseh went out of business, I ran into brand new engines that the valve stems were never ground. Very rare anymore unless it's very old, valve seats have been beaten to death from worn valve guides or at the very end of tecumseh's run with the worn out molds and dies. But only ever seen maybe 3 or 4 like that new.

another good vodeo thanks

Hi thanks for this great video. What tool do you use to remove the valve??

Hi Dony - What if the valve has too much clearance causing too much compression? This video shows how to grind it to give more clearance, but if you need less clearance? Is that adjustable?

hey! you have one of best video easy explained or easy understand. But I have one problem what I can't found out. Problem is when shut down engine it's explode in the end. what can be wrong? thx a lot for your videos I wish you all that best.

thanks Don!

yes exactly, i seldom have to lap the valves

you can use a 00 grease, lithium or white grease, i talked about it in a previous Q&A, check ebay for the filter

Great videos, I have a 5hp tech snowblower with an exhaust leak. What tool do i need to remove the valves?

Great video Don...any idea on intake and exhuast valve clearance on a Tecumseh hs50 67326k 5hp flat head? Thanks

At the shop I used to work at we would get Chinese scooters in all the time, 75% of the ones that came in the door had a stretched exchaust valve. Can be caused by running at high load for a long time, or just cheap metal, just my 2 cents and as always great vid Dony

Hi Don, I saw ICANDOIT20s’ comment & understand how that happened. What would have cause the valve to have to be ground down. Thanks again for the time & effort you spend doing these videos.

THAK YOU SIR!

Great video Dony! Any chance on a video of replacing the valves in the future?

Thanks man!!

Dony, Thank you for your continued five star videos. Please explain at what point the automatic cam decompression system; starts, then stops to function. Also with the flywheel key checking out okay, what else normally affects "pull starter kickback?" Tim.

@ronwoltz

5 жыл бұрын

Valves no set properly try again.

Hi Dony, I've read sometimes to check the clearance at top dead center and others say to drop the piston 1/4th of the way. Which way is correct and why do they suggest lowering the piston? I have an HMSK100 engine Thank you!

Dony what caused the valve to "stretch" like that? Overheating? I've never ran into this problem before.. Very interesting, thanks for showing this..much appreciated buddy..

thanks dony

Hi again Donny, as you suggested I checked the clearance on my B&S 11.5hp, and there was basically no clearance on either valve. After grinding and lapping I have 10 thousands on the intake. I know this is too much clearance, but will it make much difference on the inlet, and if so will further lapping be enough to reduce the clearance? Lapping seemed to be increasing the clearance and this is the opposite to what I expected....

Also is your Q&A coming out soon I enjoy them alot

yes canadian, i have a linkage configuration video on one of these engines i think

hey..i just put a little spot weld on the end of the valve and grounded it down to the right play. worked out fine for me...

Hi Dony. I'm rebuilding the exact engine you show in this vid and I'm at the point where I'm putting the valves in. I'm not seeing any clearance in either the intake or exhaust valves with piston at TDC. Is there anything else I should check before I go grinding down the valve stems? Thanks!

Hey Dony what is the valve clearance on a 16.5 hp briggs and Stratton flat head engine your help would be greatly appreciated, Thanks

Great tip Don , thanks , did ya get much snow over there ? almost 8 inches here in the Sault .

Nice and short.

I may be wrong I'm not an expert but I think that on most flat heads since the is no compression relief mechanics, either the intake valve or exhaust valve will have some clearance to allow the engine to turn freely at startup. please correct me if I'm wrong

not always but it is recommended

@DannyOktim, Never grind on the side of a grinding wheel, they are more likely to disintegrate and throw pieces of the wheel towards you.

Because of a badly scored cylinder, I had to purchase a 'new old stock' block for my 5hp Tecumseh HSSK50-67403U Yard Machines snow blower. I also purchased a new piston, rings and wristpin. Also purchased two new valves and a complete gasket kit. Short block is back together, crank & cam timed properly. I lapped the new valves and checked valves at TDC...before I put the cam/crank cover on I could easily see the 'lifters' were on the heel/low spot of the cam. Clearance on this engines valves are intake-.004 & exhaust.008 Intake is in spec however I have to grind the exhaust...I have a bench grinding wheel but wondering if a Dremel would work better > > > I'm a little concerned about removing too much metal.

on the flat heads it's .008 for intake and .012 for exhaust, yes I use a flat chainsaw file

thanks for watching

Hi Dony, how's it going? I just finished checking the valves on my 5hp flathead snowblower engine and found that my exhaust valve has no gap at all and my intake has a gap of .012. I realise I need to file down the exhaust a bit, but how do I make the intake gap smaller? would buying a new valve fix it?

In the states, Sears has a 25 leaf feeler gauge for sale at $5.09 right now. You could also get one from Ace Hardware.

Hi Donny - Great Videos. 1 Question. At TDC, the exhaust valve is fully seated on my engine and I can not spin it by hand. But... on the compression stroke, it seems the valve opens VERY slightly, like there is another small lobe on the cam. I can spin the valve during this slight opening, but it seats again just before TDC. Is this normal? Tecumseh HSSK50 engine.

good vedio

Just did this to a Briggs 281016. What a PITA to get the keeper back on.

Hey dony, can you explain to me how a valve (say exhaust valve) which doesn’t have any adjustments on it, would fail to seat properly over time? Ie what changes that you need to grind the valve to increase the valve clearance??

@MikeJones-rk1un

2 жыл бұрын

That is my question also. I can see things wearing and having MORE or too much clearance but how does clearance disappear?

@stubeusz123

2 жыл бұрын

If the valve seat wears then the clearance between the pushrod and the valve stem will decrease

Well done, what's your therory as to how the the length of the valve stem gets longer than when installed from the factory ?

@kevinberry6818

2 жыл бұрын

The valve doesn't get longer but it gets deeper into the seat as both the valve lip and seat wear, so it gets closer to the tappet

nice thanks a lot!!!!

Hi,would you always measure the valve clearance with the springs and retainer in situ, The reason I ask this is because,I had noticed when the springs and retainer are not placed on the valves when gap setting,they become smaller in distance once i replace the springs and retainers back in.

Hello. I have the exact same question as Blitz Hunter with the slight opening of the exhaust valve. Both valves can not be spun with the piston at TDC. However I did not check if I could spin it when there was the slight opening I am mentioning. Mine is a HSSK80. I can not get the engine to run right. It backfires, stalls and loses power. I am planning on doing a valve job but I was wondering as well if this opening is normal in the cycle and if that is really the issue with how the engine runs. Thanks.

Always interesting :D BTW is the customer let you repair his engine with the some scoring on the bore?

I have a toro 824 with a techemseh engine I'm doing the exact same thing to it and I was trying to find torque specs and bolt pattern on the head. Haven't been able to find it, do you know the torque and tightening sequence? And if you do could you also tell me where you find all your specs. Thanks in advance

That's a good review. I was expecting you to have to relap the valve seats, but it looks like that wasn't necessary. I suppose that if carbon was holding the valve up, the gap would have been too large.

question i grinded like about 004 too much on a valve ,,,,its on the loose side now can i add metal "welding " and then dress it up to save buying another one or chasing one down ,,,,thank you

Hi Dony, tell me if either of those valves are out of adjustment, will this cause the problem to the engine to start, my valves are out of adjustment and I can't even start the engine. Thanks

OK Thanks how do you know if you have taken enough off. It looks like a hit or miss kind of way. like the 0.12 how many times did you stroke the vale with the file to get the clearance. I have a nice 3.5hp 70`s vintage Ariens blower that needs lapping and do the clearance. Any info would be helpful. Thanks.

@shaggyrusso4484

7 жыл бұрын

Gary B I have the same problem on my 1979 Toro snowblower with an older Tecumseh 3.5 hp engine. its shooting flames out somewhat, but ive learned to check the valve spring itself, try and see its resistance to being compressed and possibly that could be why its not seating properly. I have had that problem on other applications as well especially on older flat head motors in general.

just a little question do you need to change the head gasket everytime when you remove the head from a flat head engine?

5W30 OR 5W20 conventional or synthetic

about a min or so after a snow blower starts is it normal when you look inside the muffler it glows red. The muffler did the same but i adjusted (i don't know what you call it) that little arm right in front of engine that a wire connects to the carb. it helped the muffler not glow but it still does when you look down inside the muffler. What would cause that? Any answer would be greatly appreciated.

YES I DO, search for valve decompressor on my channel

Hi Donyboy73, How do you know that the exhaust valve is not lifted by the automatic decompression mechanism on the camshaft? Should you turn the crankshaft an extra 1/4 of a turn to ensure the automatic decompression mechanism is disengaged before taking any measurements for the exhaust valve? BR and have a nice day.

@h2000l

9 жыл бұрын

More info taken from: www.briggsandstratton.com/eu/en/support/faqs/compression-system Compression Release System : The compression release system lifts either the exhaust or the intake valve slightly off its seat during the compression event (this is why the piston is positioned past top dead center to about 1/4" down from the top of the cylinder when adjusting valve clearances). :

Hey is the intake valve always bigger than the exhaust valve? Thanks fella

Was that flat head leaking oil out of the muffler? I've got a Briggs leaking oil out the muffler.thx

Would valve clearance being off cause the mower to pull the starter cord out of my hand, very hard when I try to start it? I have checked the crankshaft and it is not bent, and it is not hydro-locked?

it's a valve seal and yes it can be replaced

Cam you use a compression tester and if so what would be a good compression?