Snowfire flooding

[JAH76]

Maybe someone can please help me here. My original VM30 Mikuni pours gas out the needle jet in the middle when fuel shutoff is turned on. Here is what I have done to sled.
Motor has been completly rebuilt all new bearings and o-rings on crankshaft thorough northern C, new nickasel'd cylinders, new pistons rings. NEW Seals. Did leakdown test and it held 7p.s.i for 10 min. All new jets,float needle and seat, jet needle and needle jet, and new gasket. Also new choke plunger. Soaked carb In ultrasonic cleaner 4 times. Float hight us correct. Also new fuel line,clamps,and new filter. Also new line in tank and new 1 way check valve filter in tank. Tank had been flushed and cleaned.So I can get it to run(with valve ooff) after I get gas out of bottom
end .it will start to die cuz gas is off as soon as I crack the gas valve carb will fill up and flood engine if I keep gas valve on. And gas can be seen in pulse hose. Would like to add that I have changed fuel pump twice with a quality Mikuni pump(not junk) and changed needle and seat 3 times. I took off carb today cleaned it again and hooked up choke throttle and gas line but did not hook up to motor. I turned gas on and blew through gas tank vent line to fill carb up with fuel and I could see gas dripping from front of carb. Looks like it's coming up from center needle jet. Also sled is NOT up at an angle on stand it is on the floor. Sled sounds awesome with fuel off when running for a bit and revs up fast but fills up when on. Please help guys. I've got about a grand in this motor and sled is perfect except for this problem. Sorry this is sooo long.just frustrated

[nick80lf]

Few suggestions

1. Do you have the correct inlet needle. I believe these carbs use a different inlet needle compared to the bigger VM carbs. Mine had a needle for a bigger carb when I got mine. I'm thinking the vm26/26 is the correct one but it's been too long....not 100% sure.

2. Is there a problem with the float. Like a crack causing it not to float

3. Is the float upside-down

I like to use a mityvac to test inlet needles. I use my finger to put just enough pressure to compress the spring half way in the needle. Apply a few psi to the fuel inlet port and see if it leaks off. Maybe another way is to use a short length of hose fill with carb cleaner while holding the float lever and looking for drips coming out of the needle while pressing the float lever.

[JAH76]

I will check and see about another inlet needle,and I did buy new floats just to be sure and yes they are in correct. Pins down and to the inside. Thanks for responding. Very appreciated. I have a motion pro leak down tester that possibly I can hook up and put some pressure on needle and see what's going on.but that'll be tomorrow going to bed now.

[jdsledhead]

Any luck figuring this one out yet? Odd problem for sure based on all the work/diagnosis you've done so far.

[JAH76]

Sorry guys.... been awhile I was and still am super frustrated. No snow in central Iowa anyway. But what I'm worried about is the upcoming high humidity coming here on summer and my motor is not broken in. Also all the flooding in the engine might have just wasted the $1000 plus I've put in the motor anyway No luck yet.and ive even changed float needle again,cleaned carb again. Still starts with gas valve off but dies out if you turn gas on. I'm thinking cdi for some reason. I've read that you can install a setup from a kawasaki drifter that has the coil and cdi in 2 pieces.( Mine has the mailbox style all 1 piece). I've got 2 cdis and 2 coils. I'm gonna try it tomorrow as I have already hooked it up tonight. Gonna sleep on it and let you guys know what happens. I'm at a loss here.

[Matt]

I would get a different carb to try. It sounds like you've done everything you can with that carb. Ignition should be worth a shot but if fuel is pushing up through the carb and running out like you say, there's got to be something else going on.

[jdsledhead]

Sorry guys.... been awhile I was and still am super frustrated. No snow in central Iowa anyway. But what I'm worried about is the upcoming high humidity coming here on summer and my motor is not broken in. Also all the flooding in the engine might have just wasted the $1000 plus I've put in the motor anyway No luck yet.and ive even changed float needle again,cleaned carb again. Still starts with gas valve off but dies out if you turn gas on. I'm thinking cdi for some reason. I've read that you can install a setup from a kawasaki drifter that has the coil and cdi in 2 pieces.( Mine has the mailbox style all 1 piece). I've got 2 cdis and 2 coils. I'm gonna try it tomorrow as I have already hooked it up tonight. Gonna sleep on it and let you guys know what happens. I'm at a loss here.

If you have original style chrome cylinders or did a nicasil coating, you shouldn't worry about the engine being broken in. Nothing to really rust there. If concerned, spray fogging oil in the cylinders and pull it over a bunch of times. The fuel in the crankcase will eventually evaporate, so no worries there either in my opinion.

Back to the main topic. I don't think the ignition has anything to do with gas flowing out of the carb with the valve open. Also, as far as I know, you have to swap the stator as well as the coil/CDI. I've looked into this recently. The part number for the coils is different between the 82-84 Kawi ignitions (the mailbox CDI, as you said) and the earlier ones with a separate coil from the CDI. That said, if you decide to swap out, I'd be interested in the mailbox CDI unit! I could use one.

Re: fuel system. Have you followed the throttle cable installation instructions? Maybe the throttle valve needle is too far up? I don't think that should allow gravity fuel flow, but trying to cover every base. Is the fuel tank properly vented? I'd think if the needle and seat were leaking, that you would get fuel leaking all around the carb. It's been so long since I've had an issue.

Eventually I too would try a different carb even if you just borrow one from someone.

[JAH76]

Ok guys I'm back. I took a break for a bit(no snow anyway).so.i bought and installed a new cdi and separate coil for a. 83 trailfire 340. I also had and installed a known good stator and lighting coil from same sled.. low and behold sled started on 2nd pull( with choke full on and gas in carb). IT IS NOT FLOODING NOW!!!! It will rev up nice and idle but the idle is rough. But I believe that I just need to adjust slow needle. But Guys it is RUNNING. TESTED compression and it has 130 . And both cylinders are exactly the same. I'm so happy even though it's April 4th and soon I'll be draining gas and get the track loose, cuz winter is done In iowa.but I'm ready for next year. THANKS EVERYBODY FOR YOUR ADVICE AND HELP
And keeping my sanity sane. I can't wait to post pics to you all of the snowfire in use..

[nick80lf]

Glad you have it running.