Scooterotica

As you all know I have a trike derived from a 1964 Lambro Fli 175. The barrel has been uprated to 200cc (barrel stud pattern is the same), running a dellorto 30mm carb for better acceleration and a part original exhaust/silencer with an end can on it. My problem is that intermittently the engine oil is spewed out through the crankcase breather, resulting in a slipping clutch, and no further progress.
I rebuilt the engine 1800 miles ago, new crank, bearings,seals, clutch plates , in fact new everything. The engine itself runs fine. Easy to start, warms up ok, runs through all the gearing etc. The only fault is this bl:?@@dy engine oil problem.
The engine is tranverse ie the barrel points out of the side of the machine, not the front. There is no chain drive, it is driven by direct cog to cog contact inside the crankcase. The gearbox is in a little box on the back of the engine, and drives the propshaft to the rear axle. Has anyone else ever experienced this, or is it unique to my trike?? Any idea's very welcome. I am hoping to advertise the trike for sale shortly, so would like to fix the problem. Thank you in advance.........

Too much oil?
It's a long time since I stripped a Lambro engine but from memory the gearbox oil capacity is a lot lower than a normal lambretta.

Hi Ian, thanks for the thought, but the oil is coming out of the crankcase breather, not the gearbox, which is seperate on the back of the engine. I shall double check though that I have put the right amount in the crankcase. Regards Ken.

Some breather plugs are shite. If you have the type with the circlip inside, you can remove it and the washer/piece with a hole in it and pack it out with some foam, remembering to replace wsher and circlip. You should be able to blow through it with some resistance, as its only there to relieve pressure.

Edit: Oops, I have now read your post right through My tip still applies though, assuming its a similar type of breather plug

certainly worth looking at Dapper, thanks for that. I shall check what type of breather plug it has on it.