o6 yfz spitz, sputters,pops help

I recently bought an 450 yfz It ran good for about 10 to 13 hours. Then all the sudden it spits, sputters,and pops through the carb. Took to the dealer they supposedly went through the carb,checked cam timing, crankshaft timing,and valve clearance's. Everything checked out fine they even called YAMAHA and they said to put a stage1 jet kit in so they tried that with with no luck. I don't know too much about carbs but why would it run fine for 10 hours or so and then need jets all the sudden? If anyone could give me a possible diagnosis or explanation I would really appreciate it.

...it will spit ,sputter and ultimatley kill the dealer...

First, any dealer who keeps your ride for 3 weeks because of simple jetting issues, deserves to get killed, lol.

Second, this is the bike forum, not the quad one.

Third, if you expect any decent answers, please learn to write properly. Did you even notice how long the one and only sentence of your's was? Do you find it readable yourself?

Fourth, in case you really mean the '06 450f, a search will find you all the answers you need for proper jetting.

This has been said time and time before about how off the '06 Jetting is for people. Plain and simple, it's too lean. The fix? A larger pilot jet should do the trick, try changing yours out to a 48, work from there.

By the way, your dealer is a complete idiot if he cannot jet a bike correctly in 3 weeks.

By the way, your dealer is a complete idiot if he cannot jet a bike correctly in 3 weeks.

Ever think the dealer may have had a 3 week backlog and it took that long for this customers turn to come around?

I'd look for crap plugging the jets. There are no fuel filters on them and any dirt in the fuel must eventually flow thru the jets.

There are no fuel filters on them and any dirt in the fuel must eventually flow thru the jets.

:applause: Ever pull the petcock out of the tank? Tdub

I knew it was a quad after all, but I'm not negative about that, we have several quads too in our racing team.

The jetting specs for the '06 bike just don't apply, that's all.

I recently bought an 450 yfz It ran good for about 10 to 13 hours. Then all the sudden it spits, sputters,and pops through the carb.

This sudden spitting may be a result of:

- intake or exhaust leak

- clogged jets

- water in carb

- dropped fuel screw

- damaged CDI-box

- damaged stator

Did your quad get wet? How is the spark plug and -cable? You could have a broken electrical cable somewhere too.

I cannot think of other sudden causes, unless if you had the carb apart and put the slider in wrong. But that is not "sudden".

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