Please help.

After cleaning the fuel petcock screens and flushing the tank a couple of times I've got a new problem. With the carb drain plug in (closed) fuel still drips out of the float bowl. I thought I screwed up the screw so I gave it a little assistance with an o ring. That stopped the drip from the bottom of the carb but now it backs up into the air box!. I assumed a sticking float so I tore it down , removed all the jets, blew them clean and dry and made sure the float moved freely. During all this I learned why it backed up into the air box. The drain plug was not leaking but working as designed. The carb is overfilling and the overflow is coming out the drain hoze. This is why it backed up into the air box when I plugged it. I re-assembled everything and turned the fuel back on and it still leaks. What should I look at next?

 

It's a possibility that that the float needle has something between it and the seat or...it is scarred from something going through it. Also make sure that the float is not taking on fuel and no longer floating....simple checks....

 

new float valve

 

Looking back, I don't think there has been a Mikuni carb in our group that didn't leak.[img]i/expressions/face-icon-small-disgusted.gif[/img]

 

Check the composition of your oil (does it appear watery?). If so, gas from your float bowl has leaked past the piston and into the motor (not a good thing). The oil blowoff hose attaches to the air intake, which may be why you still are seeing gas in your airbox. It's coming from your motor. Change your oil, and NEVER plug the float bowl overflow hose again. I did the same thing and thought I had burnt the motor. If you don't like to smell gas during storage, turn the gas off and run your DS until it uses what's left in the float bowl.

Good luck.

 

The oil blowoff hose attaches to the air intake


???????????

 

I now have an intimate relationship with my Mikuni. I removed the float valve, bent the little tang, cleaned and reassembled. Did the clear tube measurement and gas is about equal to where the bowl mates to the carb. Is this about right?

I now have more questions. What are the two black hozes that do not connect to anything? They appear to be breather hozes coming from the carb and are about 6 inches long and are tucked up under the tank. That appears to be an easy way to get sand into the carb.

The oil blowoff hoze must be the 1" hoze coming from the bottom of the case and mates with the left air intake hoze that goes to the airbox. No gas got as high as that hoze.

After all this it started right up and no gas leak. What a way to get to know your machine.

Thanks for the help guys.

 

Nothing like trail by fire..lol...That 1" hose coming from the lower case area is the crank case vent. At least one of the small hoses off of the carb should be an over flow hose for the bowl.The other small hose should be the bowl drain hose, both should be hanging below the bowl....unless one hose that you are seeing is the fuel inlet hose that just happens to run under the tank to the fuel valve....more fun than you can have....

 

They are not the drain hoze nor the fuel inlet. There are two other hozes, 3/8th I think, coming from near the top of the carb that just end, i.e. not connected to anything. They are just tucked under the tank so I thought they were some kind of breather hozes. This is an 05 so it may be new this year. Anyone got a schematic?

 

Hmmm..ok..I'll have to look at my buddies 05....