Old Eldo blowing oil out thebreather tube

[Tkelly]

A friend started his old bike for the first time in a few years and it blew out about a quarter quart of oil thru the breather tube.Any suggestions ?I think it is a 73 Eldorado.

[Dirk_S]

Water accumulation via atmospheric fluctuation?

[moto]

A friend started his old bike for the first time in a few years and it blew out about a quarter quart of oil thru the breather tube.Any suggestions ?I think it is a 73 Eldorado.

Right away? Or over a ride of X miles? (X=?)

[Tkelly]

Didn’t say,what are the likely causes in each situation?

[guzzisteve]

Stuck flap or disc on pin w/spring in the box on block. New box used to be $25 that was awhile back. I don't trust old ones.

[jhem68]

Always an outside chance of gas seeping past the float and migrating into the sump if the petcock leaks or was left in the on position, so hopefully he checked the oil level before starting it up.  But most likely the flapper is stuck shut as Steve suggested.

John H

[Tkelly]

He traveled to MG and they gave him advice on how to clean the flap in the box.Thanks for the tips.

[michaell32]

If it was sitting for years there could be rust on the cylinder walls not allowing the rings to seal as well as they should.  Compression leaks past the rings and builds up excessive crankcase pressure.

[Antietam Classic Cycle]

A friend started his old bike for the first time in a few years and it blew out about a quarter quart of oil thru the breather tube.Any suggestions ?I think it is a 73 Eldorado.

Deteriorating chrome bores?

If it was sitting for years there could be rust on the cylinder walls not allowing the rings to seal as well as they should.  Compression leaks past the rings and builds up excessive crankcase pressure.

Eldorados had chrome plated cylinder bores from the factory and the chances of that flaking off are good. If it was fitted with aftermarket iron liners, then rust could be an issue.