Craftsman, oil in carburetor

[hrdman2luv]

I have an MTD manufactured craftsman engine (on a craftsman rider. 420 CC) I'm getting a lot of oil in the carburetor. Ever so often, puffs of white smoke. Loss of power in high grass and up hills. SO much so that it almost kills the engine.

The mower came in with a little too much oil in it. About 1/4" above full. Made adjustments to the valves. Sprayed quite a bit of seafoam spray into the carb. Cleaned the spark plug. Changed fuel filter. The air filter isn't new. It had a lot of dust in it, which I carefully blew out. There's a little bit of oil on the air filter. But just a small spot or two. The oil isn't getting that far up.
After running it, I shut it off and took the air filter off. There was so much smoke in it that you couldn't hardly see down in it.

Pull the dipstick, and no smoke coming from the crank case.

The only label on the engine.

 

[ILENGINE]

MTD engine model number is normally stamped into the block. I think I would be looking at head gasket issues to start.

 

[hrdman2luv]

MTD engine model number is normally stamped into the block. I think I would be looking at head gasket issues to start.

That's what I'm thinking too. But the guy told me he forgot to put the dipstick back in it, and ran it low. It was full when he started, 30 minutes of mowing later, it was just barely a drop on the dip stick.
With 150lbs of compression, I don't think the rings would be bad. Do you? Especially since it doesn't constantly smoke.
The only way oil can get this (or all) carbs, through the intake back up to the carb. Or through the breather tube. Right?

 

[upupandaway]

I have an MTD manufactured craftsman engine (on a craftsman rider. 420 CC) I'm getting a lot of oil in the carburetor. Ever so often, puffs of white smoke. Loss of power in high grass and up hills. SO much so that it almost kills the engine.

The mower came in with a little too much oil in it. About 1/4" above full. Made adjustments to the valves. Sprayed quite a bit of seafoam spray into the carb. Cleaned the spark plug. Changed fuel filter. The air filter isn't new. It had a lot of dust in it, which I carefully blew out. There's a little bit of oil on the air filter. But just a small spot or two. The oil isn't getting that far up.
After running it, I shut it off and took the air filter off. There was so much smoke in it that you couldn't hardly see down in it.

Pull the dipstick, and no smoke coming from the crank case.

The only label on the engine.
View attachment 34266

In the "tube" going from air filter to the carb should be conected a hose that goes to the engine block. This is to take air from inside the motor feed it back into the engine to reburn the unburned stuff. Disconnect this hose from the intake and see if it is spitting out alot of oil. If your oil is still overfull, siphon out or drain the extra oil before checking this hose.

There is a PCV- Positive crankcase ventilation to only let air OUT of the engine to go to be reburned. It should only let air out not back in. Not working will produce the oil\xcess air.
Best case just too much oil.
Worst case there is major blow by into the crankcase from worn cyl\piston\rings etc. thus alot of oil\air coming out this hose.
Either way, start by checking in this is where the "extra" oil is coming from.

 

[ILENGINE]

That's what I'm thinking too. But the guy told me he forgot to put the dipstick back in it, and ran it low. It was full when he started, 30 minutes of mowing later, it was just barely a drop on the dip stick.
With 150lbs of compression, I don't think the rings would be bad. Do you? Especially since it doesn't constantly smoke.
The only way oil can get this (or all) carbs, through the intake back up to the carb. Or through the breather tube. Right?

It is possible to have cylinder wall damage and still have good compression. Oil gets past the rings in the damaged area but the damage is low in the cylinder where it doesn't effect compression.

 

[cpurvis]

The oil ring can be bad and not affect compression, either.

 

[hrdman2luv]

In the "tube" going from air filter to the carb should be conected a hose that goes to the engine block. This is to take air from inside the motor feed it back into the engine to reburn the unburned stuff. Disconnect this hose from the intake and see if it is spitting out alot of oil. If your oil is still overfull, siphon out or drain the extra oil before checking this hose.

There is a PCV- Positive crankcase ventilation to only let air OUT of the engine to go to be reburned. It should only let air out not back in. Not working will produce the oil\xcess air.
Best case just too much oil.
Worst case there is major blow by into the crankcase from worn cyl\piston\rings etc. thus alot of oil\air coming out this hose.
Either way, start by checking in this is where the "extra" oil is coming from.

It was about 1/4" over full when I first started diagnosing it. I pulled out enough to put the level just under the full mark. After adjusting the valves, I mowed with it for about 30 minutes. When I stopped, I once again noticed a lot oil in the carb.

The PCV, If I can get to it, if I blow air back into the tube, then it's bad, right? (Not talking about compressed air)

 

[bertsmobile1]

A head gasket is about $ 5 so just rip the head off and have a look otherwise you are going to be spending $ 400 in time to find the engine is a write off or it just needed a new gasket all along
If the owner ran it low on oil check for any latteral play in the flywheel as the top bush is usually the first to go.

 

[hrdman2luv]

A head gasket is about $ 5 so just rip the head off and have a look otherwise you are going to be spending $ 400 in time to find the engine is a write off or it just needed a new gasket all along
If the owner ran it low on oil check for any latteral play in the flywheel as the top bush is usually the first to go.

Thanks for the top wobble advise.

BTW, where are you getting an MTD 951-12273 (head gasket) for $5? Cheapest I've found has been over $25.

 

[bertsmobile1]

Not had the fun of playing with the P90 engine yet so made a bold assumption
$ 10 to $ 20 Aust is what I pay for most head gaskets down here.
The Chinese gaskets come direct from China and they are usually < $ 10 Aus + freight.
IT takes a lot of searching because a lot of Chinese suppliers sites are blocked.
Also try Stens, Oregon, Prime Line & Rotary.
After market ones are out there, they are just tricky to find without a whole sale account.