Excellent video young man...I'm a 30 year mobile diesel mechanic and never had much time to mess with 4 cycles...well explained everything worked exactly like you explained my friend...ty very much....I'm fixing our mobile unit compressor so you helped me tremendously!
I strongly recommend covering the cylinder opening and piston when wire brushing or sanding anything on the head/valve area. You could use newspaper, clean shop rag, paper towel, anything to catch the grit. You definitely don't want anything other than clean oil going into there.
Convenient tools: Cut off a sturdy BBQ fork so it has about a 3/4" long fork portion. Sharpen the fork ends for easy insertion between spring bottom and retainer ring. Use a large nut as a fulcrum when lifting/compressing spring. Manipulate the spring retainer ring with a small-diameter magnet wand. Piece of cake.
Yeah, worn cam, tappets/lifters and valve seat leaving no clearance at the stem end is the reason the valve doesnt close and burns in the first place. I think exhaust clearance should be 0,3mm. If clearance is not maintained the valve is going to start leaking again in no time.
Yea, your removing those valves the hard way. I am done wrestling with valves on a flat head. I ordered the valve spring compressor today. I have a much newer snapper. Same thing, exhaust valve stopped seating all the way, otherwise engine is in good shape.
That engine ran good after, but probably would have ran perfect if you had set your valve lash, which you have to do when you do a valve job. The exhaust is .0100 and the intake is .040. Take the valves to a bench grinder end grind the end of the stems slightly until you get to it. Check them with a feeler guage afterward.
I've been a small engine mechanic for thirty plus years. I am Master Service Tech Certified for Briggs, Tecumseh, Honda, Kolher, Kawasaki, and a whole lot more. Tecumseh engines have the same gap on both valves. 0.008 to 0.012 for just about every one of their L-head engines. In my time I've literally done 1000 valve jobs. I don't know of any small engine, engine manufacturer that has a 0.040 gap especially on the intake valve. I'd be interested in what model and manufacture of engine your talking about so I can look it up, because there is always that odd ball engine.
@@andyfunke9484 Wherever that info came from that I posted, it was wrong. I have the service book for Tecumseh aluminum block L heads now. Intake is 0.008. Exhaust is 0.012. The exhaust has a larger setting because thats the one most common to stop seating from heat. I've got one apart now, it has the common exhaust valve no longer seating. Intake still seats but a 0.008 guage wont go in on that one either. Both are coming out. I'm waiting on a flat head valve spring compressor, because I am not fighting those with screwdriver's anymore. Thats for most horizontal's. Verticals have a different spec. The tell tale sign on my engine that lead to my discovery was carburetor would not adjust the engine to run smooth, it surged and popped no matter what and it was severely lacking power. If thats happening, you know your valve lash is off. Engine has over 1000 hours of run time. Otherwise engine is still in excellent condition, crosshatch in cylinder still looks great.
@@andyfunke9484 When I make a mistake, I own up to it. I'm self taught and have come a long way in the last few years. I've only done the valve lash's a few times so far and OHV's are so much easier because its right their up top and just needs to be reset with an open end and star bit and that is why I am finally just getting a valve spring compressor, because valves on flat heads are a bit harder to do. Its the first one I encountered, because it was my personal machine used commercially for many, many hours, over 1000. However I hear people complain all the time how they don't like Tecumseh's because no matter how much they adjust their carb, the engine still pops, when its actually a simple valve lash out of spec, which in itself is an easy repair, just requires you to remove everything to get to them and have a valve spring compressor and bench grinder to correct the issue. Which isn't bad for someone who does this on the regular and has the tools required to get the job done. Tecumseh snowkings are great engines.
@@Mr_Tecumseh, I hear the same complaint about Tecumseh engines all the time. Which is funny, because the Snow King engine, up until recently, was installed on about 99% of all snowblowers manufactured in North America. Consequently every time I hear someone complaining about a Tecumseh engine, it puts a tiny shot eaters grin on my face and money on my wallet. Small engine mechanics are becoming hard to find. I know of a few shops that have been running short handed for years, just because there's nobody out there to hire. I can only say become good at what you do, and you'll never have to worry about looking for customers, they'll come and find you. Remember, everybody who has a lawn, has a lawnmower, at the very least.
I usually set my valves on most small engines both at .004” and that will be good enough for the engine to run like it should. Actually it runs much better that way and I noticed that over time. All my power equipment have the valve set like that and they run like a dream
You know technically yes you could gap the valves, but what he did was very minimal. But next time perhaps. It is easy to mess that up by taking off to much. They looked like the were seating nicely.
My exhaust was turning red. I got all the parts to do the valve job. When I tried to remove the head bolts, they were all very easy to remove with no pressure. I could have used just my fingers to unloosen them. Not sure if that is an issue.
Absolutely an issue. Surprised it ran at all, the compression in that must have been very low, compounded by what sounds like a leaking exhaust valve which reduces compression even further. I recommend you install a brand new head gasket when you reassemble, unlike what Post did in this vid where he reused his head gasket. Lap your valves like he shows here, adjust your valve lash/clearance, and reinstall head w/new gasket and proper head bolt torque (tightened in star pattern!), put a new spark plug, adjust carb if needed and she will run like a scairt jackrabbit!! 🙂 Once complete and you verified it runs good, run it for 10 mins to warm up the oil, then change the oil. GOOD TO GO!
Good video. Whats the pounds for the head bolts? I got a 5 hp tecumseh. It looks like yours, but newer. Had a shop fix a valve job, gaskets. Now it sounds loud and won't slow down for road slop at all. Have you ever used lucas zinc additive, to keep the cam surfaces hard? Good job, thanks.
The valves are supposed to seat tightly down with no space. When the muffler turns cherry red from over heating or if the engine backfires, mostly when turning off these are signs that this needs to be done. When doing this the valve gaping should also be fixed.
Well the muffler does not turn orange at all and the engine starts after 3 or 4 primes. It runs a little erratic and can be hard to start sometimes. What do you think the issue is?
Your valves need to be done when the engine pops at full throttle even after attempting to dial the carb in perfectly. It can also be a backfire or rough run, as well as a muffler that turns red, but not always. Loss of power in snow can also be an indication you need to do a valve job. Before you go to the valves, make sure all the gaskets are good on the engine, especially around the carb and that the shanks on the carb arent worn, that your linkages have proper tension, that your head gasket is good, that your fuel cap is venting properly, that your using good gas and try a new spark plug. After all of that, if that engine still pops, backfires or runs rough on fast, you gotta go in clean the head, top of piston and valves, make sure your valves are sealing properlt, check your valve clearance and if necessary lap the valves like he did. Valve lash cleareance on these should be 0.008 intake, 0.012 exhaust.
When both valves are open at the same time that is the overlap stroke. Turn the crankshaft 180 degrees to be on the compression stroke. Then check your valve gap.
Sounds like you may have dropped a valve spring. But without looking at it, it's kind of like phoning the doctor and saying my elbow hurts. What's wrong with me?
Also some of those larger engines have compression release mechanisms to make them easier to start. If that mechanism breaks they are wicked tough to turn over by hand.
Excellent video young man...I'm a 30 year mobile diesel mechanic and never had much time to mess with 4 cycles...well explained everything worked exactly like you explained my friend...ty very much....I'm fixing our mobile unit compressor so you helped me tremendously!
I love all your videos so interesting and educational. At 70 y/o I still search educational vids.
I strongly recommend covering the cylinder opening and piston when wire brushing or sanding anything on the head/valve area. You could use newspaper, clean shop rag, paper towel, anything to catch the grit. You definitely don't want anything other than clean oil going into there.
I liked seeing a DIYer tackling this job.
Convenient tools: Cut off a sturdy BBQ fork so it has about a 3/4" long fork portion. Sharpen the fork ends for easy insertion between spring bottom and retainer ring. Use a large nut as a fulcrum when lifting/compressing spring. Manipulate the spring retainer ring with a small-diameter magnet wand. Piece of cake.
I like this idea. Do you only keep two of the fork prongs and cut off the ones in the middle?
@@jmc5341 a BBQ fork, it only has 2 prongs
Yet another type of video I didn't expect from this guy
Hey thank you. I’m going to do this in my Ariens 824
Interesting to see the inner parts of the engine. Thanks for the explanation. Too bad we barely get snow anymore where I live. :-(
Vincent said it first. Whenever you lap valves it changes the gap and you have to grind the steam to get the proper clearance.
Yeah, worn cam, tappets/lifters and valve seat leaving no clearance at the stem end is the reason the valve doesnt close and burns in the first place. I think exhaust clearance should be 0,3mm. If clearance is not maintained the valve is going to start leaking again in no time.
The cover you removed is the crankcase breather. Not the intake. The intake air goes in through the carburetor.
Yea, your removing those valves the hard way. I am done wrestling with valves on a flat head. I ordered the valve spring compressor today.
I have a much newer snapper. Same thing, exhaust valve stopped seating all the way, otherwise engine is in good shape.
the cross hatch pattern on the cylinder wall is supposed to be there so the oil sticks to it.
Nice job man
@5:25 that is the PCV Positive crankcase ventilation.
Good job bro.
That engine ran good after, but probably would have ran perfect if you had set your valve lash, which you have to do when you do a valve job. The exhaust is .0100 and the intake is .040. Take the valves to a bench grinder end grind the end of the stems slightly until you get to it. Check them with a feeler guage afterward.
I've been a small engine mechanic for thirty plus years. I am Master Service Tech Certified for Briggs, Tecumseh, Honda, Kolher, Kawasaki, and a whole lot more.
Tecumseh engines have the same gap on both valves. 0.008 to 0.012 for just about every one of their L-head engines.
In my time I've literally done 1000 valve jobs.
I don't know of any small engine, engine manufacturer that has a 0.040 gap especially on the intake valve.
I'd be interested in what model and manufacture of engine your talking about so I can look it up, because there is always that odd ball engine.
@@andyfunke9484 Wherever that info came from that I posted, it was wrong.
I have the service book for Tecumseh aluminum block L heads now. Intake is 0.008. Exhaust is 0.012. The exhaust has a larger setting because thats the one most common to stop seating from heat.
I've got one apart now, it has the common exhaust valve no longer seating. Intake still seats but a 0.008 guage wont go in on that one either. Both are coming out. I'm waiting on a flat head valve spring compressor, because I am not fighting those with screwdriver's anymore.
Thats for most horizontal's. Verticals have a different spec.
The tell tale sign on my engine that lead to my discovery was carburetor would not adjust the engine to run smooth, it surged and popped no matter what and it was severely lacking power. If thats happening, you know your valve lash is off. Engine has over 1000 hours of run time. Otherwise engine is still in excellent condition, crosshatch in cylinder still looks great.
@@andyfunke9484 When I make a mistake, I own up to it. I'm self taught and have come a long way in the last few years. I've only done the valve lash's a few times so far and OHV's are so much easier because its right their up top and just needs to be reset with an open end and star bit and that is why I am finally just getting a valve spring compressor, because valves on flat heads are a bit harder to do.
Its the first one I encountered, because it was my personal machine used commercially for many, many hours, over 1000.
However I hear people complain all the time how they don't like Tecumseh's because no matter how much they adjust their carb, the engine still pops, when its actually a simple valve lash out of spec, which in itself is an easy repair, just requires you to remove everything to get to them and have a valve spring compressor and bench grinder to correct the issue. Which isn't bad for someone who does this on the regular and has the tools required to get the job done. Tecumseh snowkings are great engines.
@@Mr_Tecumseh, I hear the same complaint about Tecumseh engines all the time.
Which is funny, because the Snow King engine, up until recently, was installed on about 99% of all snowblowers manufactured in North America.
Consequently every time I hear someone complaining about a Tecumseh engine, it puts a tiny shot eaters grin on my face and money on my wallet.
Small engine mechanics are becoming hard to find. I know of a few shops that have been running short handed for years, just because there's nobody out there to hire.
I can only say become good at what you do, and you'll never have to worry about looking for customers, they'll come and find you.
Remember, everybody who has a lawn, has a lawnmower, at the very least.
I usually set my valves on most small engines both at .004” and that will be good enough for the engine to run like it should. Actually it runs much better that way and I noticed that over time. All my power equipment have the valve set like that and they run like a dream
You know technically yes you could gap the valves, but what he did was very minimal. But next time perhaps. It is easy to mess that up by taking off to much. They looked like the were seating nicely.
thank you
My exhaust was turning red. I got all the parts to do the valve job. When I tried to remove the head bolts, they were all very easy to remove with no pressure. I could have used just my fingers to unloosen them. Not sure if that is an issue.
Absolutely an issue. Surprised it ran at all, the compression in that must have been very low, compounded by what sounds like a leaking exhaust valve which reduces compression even further. I recommend you install a brand new head gasket when you reassemble, unlike what Post did in this vid where he reused his head gasket. Lap your valves like he shows here, adjust your valve lash/clearance, and reinstall head w/new gasket and proper head bolt torque (tightened in star pattern!), put a new spark plug, adjust carb if needed and she will run like a scairt jackrabbit!! 🙂 Once complete and you verified it runs good, run it for 10 mins to warm up the oil, then change the oil. GOOD TO GO!
Good video. Whats the pounds for the head bolts? I got a 5 hp tecumseh. It looks like yours, but newer. Had a shop fix a valve job, gaskets. Now it sounds loud and won't slow down for road slop at all. Have you ever used lucas zinc additive, to keep the cam surfaces hard? Good job, thanks.
Thank you!
think i have to do this on my machine canadiana 828, have installed a new carburator, and it is still hard to stert when it is cold
you went through all that and didn't set your valve lash/gap
Hey. Realistically given the generation that is living now. What he did is rocket Science to most people. 😉
In this type of engine there is no adjustment for valve lash.
@@Justme-jt1ef you grind 1 thousands at a time off the valve stem u ntill you get the the proper clearence, 10 for exhaust and 6 for intake
What was the valve clearance he didn’t do that
Me forgetting he had a wirebrush on the grinder 😱😂
How do you know when a valve job needs to be done? How are the valves supposed to look?
The valves are supposed to seat tightly down with no space. When the muffler turns cherry red from over heating or if the engine backfires, mostly when turning off these are signs that this needs to be done. When doing this the valve gaping should also be fixed.
Well the muffler does not turn orange at all and the engine starts after 3 or 4 primes. It runs a little erratic and can be hard to start sometimes. What do you think the issue is?
@Brian Mott - That sounds like you may need to adjust the carburetor; and, the engine is cold. How does it start after it's warmed up?
Your valves need to be done when the engine pops at full throttle even after attempting to dial the carb in perfectly. It can also be a backfire or rough run, as well as a muffler that turns red, but not always. Loss of power in snow can also be an indication you need to do a valve job. Before you go to the valves, make sure all the gaskets are good on the engine, especially around the carb and that the shanks on the carb arent worn, that your linkages have proper tension, that your head gasket is good, that your fuel cap is venting properly, that your using good gas and try a new spark plug.
After all of that, if that engine still pops, backfires or runs rough on fast, you gotta go in clean the head, top of piston and valves, make sure your valves are sealing properlt, check your valve clearance and if necessary lap the valves like he did. Valve lash cleareance on these should be 0.008 intake, 0.012 exhaust.
When both valves are open at the same time that is the overlap stroke. Turn the crankshaft 180 degrees to be on the compression stroke. Then check your valve gap.
Was thinking this too. Could have just turned it to TDC and checked/adjusted the valves.
When I cant find my star screwdriver I just use a torx. They work almost as well.
You sound like a man with a paper asshole a star screwdriver is a Torx
+12hp briggs hard To turn over whith spark plug in
Sounds like you may have dropped a valve spring.
But without looking at it, it's kind of like phoning the doctor and saying my elbow hurts. What's wrong with me?
Also some of those larger engines have compression release mechanisms to make them easier to start. If that mechanism breaks they are wicked tough to turn over by hand.
all these wannabe techs,why i am ouy of a job.
Probably because you have a grade 3 education ,learn how to spell FFS !