filling crankcase w / gas help

Hi my name is Bill im new here too , ive got a 1983 midnight maxiam , have cleaned and kited the carbs and now ive changed the oil 3 times in 0 miles due to its flooding the crankcase w gas , ive checked the float level all are within limits , now what ???????

 

welcome to the forum, the vacuum diaphragm in the fuel petcock may have a hole in it.

FU

 

Welcome,

If the fuel petcock needs work here is the link to see the internals and rebuild:

http://www.xjbikes.com/forums/index...ng-the-yamaha-vacuum-fuel-valve-w-pics.25058/

By checking the floats did you do a wet set or dry? Here is a good link for doing the wet set:

http://www.xj4ever.com/setting fuel levels.pdf

It is really essential that a wet set be done to verify the level is correct and to be absolutely sure the float valves are functioning properly. The how-to doesn't mention it, but I usually let the carbs sit at least an hour on the external tank with the gas on just to make sure there is no seepage past the float valve.

And, lots of more good info on the carbs:

http://www.xjbikes.com/forums/index.php?threads/in-the-church-of-clean.14692/

And a ton of information on the XJ series here:

http://xjbikes.com/forums/index.php?threads/the-information-overload-hour.27544/

 

One thing that can also cause that trouble (even with tht floats working correctly) is the washer that sits under the float needle seats. They can crack as they age, and will allow fuel to seep into the float bowls (and consequently the engine) overnight. Were they replaced when you cleaned the carbs?

 

I had a similar issue... I was dumping fuel from the carbs into the airbox which in turn seeped into the the crank case. Turns out the rubber tips on my neeles were bad and wouldn't seal properly. Just something else to add to your list of maybes. Good luck.

 

Ok I checked all I could re set floats adjusted needle hanger wires no more flooding but I have a sooty plug in the #3 plug , 1 2 & 4 Are just rite on the color so what now ? Pull carbs again. And reset #3 float ???

 

Have you adjusted the pilot screw on that carb?

 

no i have not i have read alot and was under the impression that was a no no ??

 

Adjusting the pilot screws is a must do. They were set at the factory and sealed with a aluminum plug to prevent the general public from adusting them; as was required by EPA rules. The screws are meant to be adjusted, and will need to be adjusted to get your fuel/air mix correct at idle.

Carb info begins 1/4 of the way down this thread. http://www.xjbikes.com/forums/index.php?threads/the-information-overload-hour.27544/

 

If the screws have never been adjusted, they are under a BRASS plug right next to the enricher plunger. You will have to carefully drill them so you can pry them out. The mixture screws are directly underneath. You can not to a thorough carb cleaning without pulling the screws out and cleaning those passages as well.