1983 XJ750 Maxim Gas in the airbox

Hello everyone. For starters this is my first motorcycle(and my first time ever joining a forum site) and it has some issues but one i wanted to bring to attention was the fact I found gas inside the airbox. Another symptom it's having is it dying until it's been ridden maybe 10 minutes and pretty bad gas mileage.

I so far have synced the carbs, adjusted the fuel screws, put new spark plugs, changed the oil, as well as running some seafoam through it(the gas that was in it when I got it was horrid).

I normally work on cars so this stuff is a bit new to me which I should also note this is my first time working on carburetors as well but I'm trying to figure out what might be causing that. Any help would be massively appreciated.

 

Sounds like gas has been leaking into crankcase. Open the filler cap and does it smell like gas and check the level in the window. Or float level too high causing overflow. And maybe time to rebuild carbs via @church of clean.

 

Gas gets into the crankcase in one way. One or more floats are stuck, or teh float needles aren't sealing. Fuel metering into the float bowl is controlled in the same way as water metering is in a traditional toilet. A float lifts as the float bowl fills, until it presses a needle against the needle seat and shuts flow off.

You must correct this problem before starting the engine again. Fuel contaminated oil does not lubricate well, and can be dangerous. An overfilled crankcase can result in serious engine damage.

IN THE CHURCH OF CLEAN

 

Sorry I took a while to get back to y'all. Yea the oil smells like its mixed with gas, I didnt realize the crankcase breather was right where I found gas in my airbox. Im gonna rebuild the carbs soon but I was thinking I might also relocate the crankcase breather with a pod filter. That way even if my carbs mess up again gas can't get into the oil. Is there anything I should consider before doing that though?

 

That won't keep gas from getting into the oil. The stock breather setup is just fine in my opinion

 

How else would gas enter the oil(other than blowing past the rings) except through the current breather location with the current carb problems?

 

You're misunderstanding this. The breather has nothing to do with fuel in your airbox. The fuel comes out of the intake end of the carbs, runs back into the airbox, and either leaks out of there or just pools, depending how long its been seeping there.
Fit a set of float valves, set the heights, change the oil and away to go.
Leave the breather pipe where it is.
Don't mean to preach, ignore advice if you want.
Let us all know how it goes?

 

I think you may have misunderstood me actually, I know that the crankcase breather has nothing to do with gas in the airbox. I brought up changing the breather location so that if the carburetors have this issue again down the road and gas gets into the airbox from the carburetors that it has no route to get into the oil. I was just asking about anyones experience with relocating it but of course after the carbs are fixed.

 

Gas gets into the oil through the cylinders, not just the breather (it's actually less likely to get in through the breather, but that does depend on how the bike is parked).
Gas will leak right past the rings.

 

I think I may have misunderstood you from the get go in that case. Because from this I thought you meant that with the gas getting in the airbox from the carbs and pooling by the crankcase breather, I naturally assumed(which I assumed wrong apparently, my bad on that) that was allowing gas to get into the oil. So its just leaking past the rings when the bowls overflow then?

 

Correct. Technically it is possible for gas to enter the crankcase through the breather but is less likely than through the rings

 

Ahh ok now I gotcha well thanks alot y'all. I'll let you know how it goes.

 

Got there in the end. That's the problem with communicating in statements, it gives no chance to say - "pardon me?"
And everyone else knows what we're thinking...