1983 xj750 maxim

What would cause oil to come up into carburetor?

 

It is probably the crankcase breather pipe which goes from the left side of the engine (from the stub on the engine cover behind the starter motor) to the airbox? Take the air filter out and check is there is any oil on it and in the airbox. That is the only way I can see oil getting into the carburettor. How much oil is in the carburettors? Have you checked your engine oil level?

A faulty tap on the fuel tank can fill the engine with fuel in certain circumstances I understand but I think the most likely cause is the breather system on the engine.

 

If you're getting oil up through the breather tube, then you probably have a crankcase full of fuel-polluted oil, that s a good way to overheat or blow up. Stop riding NOW and take a whiff at the oil filler. Smell like gas?

Yup-- you have a leaky petcock AND at least one leaky float valve.

Nope--you have something going on internally where there is too much internal engine pressure. Find out the cause.

 

Definatly from crankcase breather, usually this is caused by overfilling the oil, when I got my bike it was puking oil from the breather (no air box so it was running all over the engine and Dangerously! In front of the rear tire! Yikes! )
It needed an oil change anyhow, when I dumped the pan there must have been 5L or more of oil in it!
I filled it to the proper level on the sight glass, bike vertical on the tires NOT on the side stand! It stopped immediately.
Hope this helps

 

Yes must be hydraulic pressure forcing oil into the airbox via the breather pipe. If it is petrol that is in the crankcase as Hogfiddles commented on that is potentially dangerous.

 

Most people put a small filter on it, or a hose and then a small filter. Wouldn't want water getting down in there.

How does it run with the pods?

 

the shift cover gasket has a large area that doesn't seem to seal anything, it's a baffle to keep oil from flying around and getting into that breather pipe. if you've never been in there it might be worth a look

 

Haven’t got it running yet, only had it delivered today, I’ve ordered new spark plug caps as one is missing, going to remove and clean carbs and air filters whilst I wait for them, then it’s the moment of truth!

Thanks for the advice, I realised after I’d posted that I’d have to put something on it to stop water getting in. I’ll have a look into some filters.

 

Cheers, I’ll have a look in there tomorrow, there’s nothing in there that shouldn’t be.

 

small pods shown in this link
https://unifilter.com/online-catalog/clamp-on-air-filters/

1.5 x1.5 inch male or female

 

Thanks, ordered the filter this morning

 

Use the hose that was there and mount a filter on the end of the hose. Tuck the filter and hose up away from the footpeg so your pantleg doesn’t stink.