pw50: how much oil inside crankcase?

Hi, I am rebuilding a pw50 engine. After opening removing the cylinder and looking inside the crankcase, there is quite a lot of oil inside. I am new to 2 stroke engines and I can't say if this is normal or not. Before the rebuild, the engine was smoking badly. Is the right oil seal shot and leaks oil in the crankcase from the transmission? Thanks!

Hi, I am rebuilding a pw50 engine. After opening removing the cylinder and looking inside the crankcase, there is quite a lot of oil inside. I am new to 2 stroke engines and I can't say if this is normal or not. Before the rebuild, the engine was smoking badly. Is the right oil seal shot and leaks oil in the crankcase from the transmission? Thanks!

There shouldn't be any oil (in any quantity) inside the crankcase on a 2 stroke. There will be an oil/gas mixture coating on everything (that's how it's lubricated), but there shouldn't be any standing oil in there.

It sounds like either the carb needle stuck and filled the crank case with oil/gas mix, or the oil seal is shot and it allowed transmission oil to enter the crankcase cavity.

i think he means the gearbox. its not allot, like a 1/3 of a quart.

i think he means the gearbox. its not allot, like a 1/3 of a quart.

If you remove the cylinder and look straight down into the crankcase, that's not the transmission/gearbox.:thumbsup:

There shouldn't be any oil (in any quantity) inside the crankcase on a 2 stroke. There will be an oil/gas mixture coating on everything (that's how it's lubricated), but there shouldn't be any standing oil in there.

Hi, thanks for answering. I would not say there is standing oil there but everything inside the crankcase is WELL coated in oil. Same for piston and the inside of the cylinder. Before the rebuild the engine was smoking badly although it did not oil foul the plugs much. There were oil drips at the end of the exhaust pipe too. I'll change the right crankcase oil seal and rebuild the top end anyway.

Hi, thanks for answering. I would not say there is standing oil there but everything inside the crankcase is WELL coated in oil. Same for piston and the inside of the cylinder. Before the rebuild the engine was smoking badly although it did not oil foul the plugs much. There were oil drips at the end of the exhaust pipe too. I'll change the right crankcase oil seal and rebuild the top end anyway.

Sounds like a crank case/trans seal to me.

Might want to look into if the bearing is bad down there-that's usually what causes them to fail is endplay in the crankshaft due to bearings going kaput.

Also, if you're in there, may as well put a new seal on the other side, too.

if you pull off the cylinder and stick a stick or ruler etc down into the crank caes all the was to the bottom of the case and then pull it back out you will see where the oil and gas seperate and there should be about 1/4 to 1/2 inch of pure oil in the bottom anymore then this you for sure have a leaky tranny seal,

i bet you dont have a bad crank seal probably just needs a new top end.

sorry, i just scanned the post quickly.

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