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YZF600R carbs on FZR not running

Posted: Thu Mar 18, 2010 5:18 am
by match417
did anyone have to change their pilot jets out to a smaller diameter so the bike would actually start up? I don't want to adjust the air/fuel mix screw because that will throw off the high rpms. My bike isn't running, and hasn't ran with these carbs on it, I sold my stock ones.

Re: YZF600R carbs on FZR not running

Posted: Thu Mar 18, 2010 7:04 am
by cad600
To my knowledge, you are the only one to try running YZF carbs on a FZR engine.

But if you look at Factory Pro's web site, you'll notice that the jet numbers for the non-ram air carbs are smaller than the ram air carbs. So it might be worth a try.

Re: YZF600R carbs on FZR not running

Posted: Thu Mar 18, 2010 11:38 am
by sweekster
Actually FasterthaUr's 4/6 hybrid runs YZF carbs as well. I do know that 97+ Thundercat carbs are set up for ram air and the jetting is different so if your carbs came from a thunder cat then yeah..change out the jets.

Re: YZF600R carbs on FZR not running

Posted: Thu Mar 18, 2010 12:18 pm
by match417
I remember talking to fasterthanUR about his carbs before I put mine on. His were on his bike already when he got it. And he said that it looked like nothing was changed, his A/F mix screw caps weren't touched, and he probably wouldn't know if the idle jets were changed w/o pulling his off and looking inside. I guess it wouldn't hurt to pull off the carbs and put smaller idle jets in, I'm not changing out the mains since they work off of vacuum created by the engine. I have a lot of extra jets lying around, and I know I have stock ones.

Re: YZF600R carbs on FZR not running

Posted: Mon Mar 22, 2010 5:24 am
by match417
YZF600 actually has smaller pilot jets than the FZR600, I just opened up both carbs and compared the jets, they are smaller. And the jets don't swap in anyway, different thread diameter. So I'll either have to carefully drill out these jets (not gonna try it) or find other jets from Keihin carburetor set that are the same size and also thread in. The main jets in the YZF are considerably larger than the FZR though.