Airbox filling with oil

Bike is a 78 Cimatti Gran Prix XL with a V1

When I first bought it the airbox was full of some sort of black liquid. It was probably oil but it wasn't very viscous and just poured out easily. Probably oil and gas or maybe condensation - not totally sure. I didn't think much of it at the time.

Now whenever I take off my airbox I can find about a teaspoons worth of blueish 2 stroke oil in the bottom of the airbox (I have the larger one with the two holes facing backward as pictured).

It's not a huge deal because It's a large airbox and I can just keep wiping the oil out of it, but I wanted to know if this was an indication of a larger issue.

It's all oil, no gas mixed in, very viscous. I did have some issues running too much oil but I've leaned it out and now the bike rides great so it could be from that.

Thanks for any help


Re: Airbox filling with oil

It's either coming from the clutch bath or the fuel. Are you mixing blue 2 cycle oil in your gas? Flooding or running rich.

Re: Airbox filling with oil

pretty normal to have blowback on a pp motor, that's why its good to run a box, it holds that fuel fog so it'll burn up. better gas mileage, quieter, Jet it correctly and just drill a hole on the bottom and have it leak out.

Re: Airbox filling with oil

Willyrd Traut /

I had a similar issue on my minarelli too, I would also double check that your float needle is in good condition too.

Re: Airbox filling with oil

4-stroking always was the cause of mine. Running too rich on fuel.

Re: Airbox filling with oil

Michael Branscombe /

a lot of two strokes just do that, even with them tuned right and carb cleaned and set up well. it is a little spit back - what you can do is take the airbox off and run it for a minute, if it is just a little fine mist - not bad, if it is spray that splatters - your carb needs work or something else is off. if it is just the mist - most of it just gets sucked back in and burned up, the oil your finding is just what was as a little oil settled out of the fuel. if it doesn't run poorly and it is a fine mist, you'll probably make yourself crazy or make the issue worse by trying to fix it.

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