Smoking 10hp tecumseh

[mark123]

Our 10 hp tecumseh spits oil out of rubber crankcase vent and burns oil . Are these engines worth fixing, would honing and new rings solve the problem? It starts and idles/runs fine.

 

[bob58o]

Here's a thread about Tecumseh flat heads burning oil. I'd probably try new rings.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/2676459/2

Princess Auto might be far for you and the PowerFist 420cc Electric start is $400.

 

[Hellion]

Any engine is worth rebuilding if the cost and effort is less than a new one...and especially if it is something you can enjoy.

Maybe the crankcase vent is toast?

Tear it down and inspect
Check cylinder for scoring
Measure piston ring end clearance...

 

[mark123]

I removed crankcase vent and cleaned it up. It simply is just a 90 degree hose open all the way through, no 1 way valve or anything. There is some mesh material behind the cover then a metal plate with some holes in it. Is this the way it should be. Also I checked compression, only 85 psi with electric starter and throttle wide open. Is there a decompression mechanism on this similar to Hondas/clones that would give false reading? Starts instantly, idles perfect....I wouldn't expect that with low compression.

 

[anickode]

Tecumseh - old Indian word, means "smokes like teenager with peace pipe hot boxing in teepee"

 

[OzFab]

It simply is just a 90 degree hose open all the way through, no 1 way valve or anything. There is some mesh material behind the cover then a metal plate with some holes in it. Is this the way it should be.

Yes

Also I checked compression, only 85 psi with electric starter and throttle wide open. Is there a decompression mechanism on this similar to Hondas/clones that would give false reading?

Yes

Tecumsehs biggest downfall was their carbs; great engines, rubbish carbs; if you can source a rebuild kit, I'd take that path... with a new carb...

 

[Hellion]

What 10 hp engine is it? Model number and designation, please. Too much conjecture going on here without solid facts.

Is it a flathead or OHV engine?

You need to pull the head and have a look at your cylinder wall--if it's scored badly, you're likely getting blowby--engine oil getting past the rings and into the combustion chamber.

You could have a blown head gasket.
Your PCV/Breather valve could be blown too, or clogged.

Hey how about some pics? Or would you prefer to keep us in the dark....

 

[mark123]

It is a 10 hp "power sport" tecumseh flat head. I took pcv valve out and disassembled/cleaned it. Little bit of smoke pulsing out of vent tube. If I open oil filler there is smoke pulsing out of it as well. Other than the oil spitting it starts, idles and runs perfect.

 

[Kentucky Boy]

Bad or broken rings, scored cylinder or maybe cracked piston...I've seen that before. My 2 cents.

 

[ezcome-ezgo]

Tecumseh not smokem peace pipe. Make heap aching head. Chief throw in buffalo patty.

 

[KartFab]

Our 10 hp tecumseh spits oil out of rubber crankcase vent and burns oil . Are these engines worth fixing, would honing and new rings solve the problem? It starts and idles/runs fine.

I fixed mine up enough to sell it for $250. Worth fixing to get rid of in my opinion, not to keep. it had that same issue, which can also be worn valves/guides, or even the little drain hole in the vent compartment being clogged up. It was just a big pain in the butt, so i sold it.

 

[mark123]

I just drilled drain holes in crankcase vent a bit larger as suggested by many YouTube videos. Seems to have helped, not spitting anymore. There are tons of videos on there regarding this problem.