Quick Warrior Mikuni Carb Question

[E36graduate]

Okay...just picked up a sweet 350, however need to clean up carb from the last ride in 2011 in Moab, UT (previous owner).

I got the carb off without effort but noticed there is a little vent tube that connects where the intake boot meets the carb....the hose is basically exposed at the end opposite of where it clamps into the carb intake. It has to go somewhere and I can't figure it out?

This is a small hose, not to be confused with the breather hose from the crankcase that goes into the intak boot.

It is typically #8 on the diagram and called:

PIPE
1UY-14197-00-00

Any help where this goes would be appreciated. Besides a good carb cleaning, could this be another reason the bike doesn't want to idle?

 

[Gen1Pat]

That is a vent hose for the float bowl. It goes no where. When fuel is used, and the level goes down in the flaot bowl, suction is created, and without that vent, the suction would be so great, that it would choke itself and no fuel would get to the engine.

 

[E36graduate]

thank you sir.....i got the quad running after cleaning the carb and she is purring now.

 

[Gen1Pat]

No prob.

 

[E36graduate]

Do these warriors tick intermittently? Seems like after getting the motor warm and the oil thins out, i hear some ticking....

not sure if the ticking is present off idle but can be heard now and then when sitting still?

 

[Gen1Pat]

The are known to have very noisey valve train. It could also be that your timing chain is stretched, and needs replacement. Check your valve clearence, and see what it does. Another thing to do is to remove the timing chain tensioner, to see how much the plunger is out. Just put the engine on TDC(align cam and crank marks), remove the 12mm plug/bolt from the back of the tensioner, a spring will come out with it, then remove the tensioner itself, and see how far the plunger is out, and how much further it has left till it is all out.

 

[E36graduate]

readjusted the valves to the tighter side of the spec and noise seems to have dissapeared.

Now i have an intermittent pop/backfrire/misfire when I am going slowly with minimal throttle. I have been washing the quad quite a bit since I've got it and it's been in rain quite a bit. I've recleaned the jets and carb out along with the air filter. I'm leaning towards the Throttle safety switch? Any suggestions?

 

[Gen1Pat]

That could be because the valves are too tight. Yeah, you have them withein spec, but, not all engines are the same. If it wasn't doing that before you adjusted the valves, I'd look there.

 

[E36graduate]

I adjusted to valves to the extreme of both spec range (tight and loose) and the pop is still there intermittently. Going to look at the shut off switches everyone talks about because this feels just like when your on a dirt bike going on and hit the kill switch for a split second and get a quick backfire.

Good thing is the valve tick has been pretty much eliminated, even after getting engine nice and hot!

 

[Gen1Pat]

Have you looked at the intake manifold for cracks.

 

[E36graduate]

yep...intake manifold checked and also used some permatex to help seal. I unhooked the clutch saftey switch and still there, however when I unhooked the emergency brake wires, it seemed to have solved the issue......is that possible?

 

[Gen1Pat]

Yes it is. Very common. Luckily, owning a 1st gen, I don't have to worry about that crap. Lol

 

[E36graduate]

Problem with the yfm350 cutting out continued after sitting unridden for a few weeks. Hard to start. Once started cuts out and doesn't want to run. Finally took off seat and noticed boat load of fuel in air box. Now I know what the little drain plug is under the air box. Drained oil. Cleaned carb. Adjusted float bowl.....starts right up and I make sure to shut off pet cock after driving. I think the fuel was just dumping into the crank....I mean the when I drained the oil there must have been about 4 quarts of oil/fuel that came out.....

 

[Gen1Pat]

Check your float height. That is the most common problem with the fuel flooding both the engine and the carb. But, yes, turning the petcock off is the best thing to do.