Fuel in crankcase, believe it was error on my part, seeking opinions

1982 Yamaha 750 Maxim. Last year I cleaned and rebuilt the carbs. 1 month later I wrecked and broke my left ankle. Up until that point it seemed to be running fine except it needed a new battery. So from August of last year till a few weeks ago it was sitting in garage.

Replaced the battery and the thing was purring like a kitten. I accidentally left the petcock in PRI mode, so basically gravity did the rest and let the gas kept going. Now this is where I feel it could be one thing or another.

If the petcock is left in PRI and the floats are set correctly will the gas keep on going down to the crankcase, due to the fact it's bypassing the diaphragm? Or is it just a stuck/incorrectly set float needle?

The reason I'm asking is because up until this past Tuesday the petcock has always been set to ON. I can't remember exactly why I switched it to PRI, but I forgot to switch it back to ON before I left for a couple days. When I got back there was oil all over the floor, in the airbox, on the air filter. I can't do a sniff test, sense of smell is horrible, but I did add some extra oil and was able to see the oil go down to the bottom in the view window and see the gas mixed in.

 

Leaving it in prime was a mistake, but the float valves should have held. So they need attention, or you have rust in your tank which can cause then to pass. The trouble is, unless you connect a clear tube to each one and set it to pri again, you won't know which one is passing. Assuming it is only one of them of course.

 

That's what I figured happened with the float. I cleaned the rust out of the tank last summer when I rebuilt the carbs. Guess I will have to check each individual carb.

 

What exactly did you do when you cleaned and rebuilt the carbs?

Which new parts were used, and what brand?
There are at least two manufacturers that supply incorrect float needles.
Did you wet-set the fuel levels?
Did you make sure to put the floats back in the right way (they can easily be installed upside down).

If the culprit is flakes of rust, install a sintered-bronze fuel filter inline between the petcock and the carb fuel T.

 

try setting the fuel to on and pull out 1 float bowl drain screw at a time, then go to prime and give each carb a little rinse out. try to catch the gas and look for chunks.
might be all you need, might save a lot of work
don't let it set on prime

 

I picked up the MOTOKU carb kit from Amazon. If there is a better kit out there right now that I can purchase to rebuild them I'll pick it up, if you have any recommendations.

I put the floats back in the right way as well, the one thing I did forget to do is wet-set them, I knew I forgot something thank you for that.

 

When it comes to carbs I get everything from Chacal. Too much work involved not to have the right parts. info@xj4ever.com will get you to the right place.

 

I have never heard of that brand. If the float needles continue to be a problem then get replacements from @chacal , info@xj4ever.com