sick yamaha fz1

I've got a 2004 yamaha fz1 with 5000 miles on it.It never missed a beat until it fouled the plugs on start up.Replaced the plugs,worked well for awhile.Started fouling the plugs again.Last time i tried to start it, it even backfired loudly.Anyone ever hear of this kind of problem? Pulled one of the plugs and it was wet but had spark.Thanks,jim  

Too much fuel or not enough spark?  Try posting this question at the FZ1 Owners forum: http://www.yamahafz1oa.com/forum/  There's lots of knowledgeable people over there.

-Paul  

Jim, I vote for too much fuel. Is the bike FI or carbuerated?  

Try http:\\www.nyfz1oa.com as well.  I just started this site up, there's not allot of activity at the moment but I'm hoping it will grow.

Yamaha FZ1 riders in the NY tri-state area  

As an FZ1OA member (same username, SO_FUN) my inclination (since your first gen FZ is carburated, not injected like the second gen) is that the fuel mixture screws are incorrectly set up from the factory as nearly every single carb set has been that I've heard  about or seen.  I run with several guys from the FZ1OA forum & nearly all of us have done a carb kit at one time or another.

I can't think of one carb set that came from the factory with all the fuel mixture screws set correctly, i.e., all of them were set at different levels.  #1 on mine was even entirely closed/screwed all the way in.  Crazy!

That said, my bike always ran too rich with the stock carb set up, though I wasn't fouling plugs or backfiring.  That stock muffler is so huge it swallows up every bit of sound the engine can make.  

Have you tried an aftermarket high-flow air filter yet?  That would help get more air to your induction system & lean out the fuel mixture headed to the engine.  Please dig around on the FZ1 Owner's Assocn. forum, there's literally speaking everything you need to know about owning a first generation FZ there.  www.yamahafz1oa.com

~ SO_FUN