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Carbi Jetting
Posted: Tue Nov 03, 2009 4:40 pm
by buzzawak
Question: wondering the performance (or ridability) difference between using the same size main jet in all 4 carbies compared to having the outside two carbies jetted different to the inside two?
Re: Carbi Jetting
Posted: Tue Nov 03, 2009 5:48 pm
by Dragon
Not doable!!
You have to have the same size jets on all carbs...
Re: Carbi Jetting
Posted: Tue Nov 03, 2009 6:18 pm
by sweekster
Dragon wrote:Not doable!!
You have to have the same size jets on all carbs...
Not true..for example...the FZR 1k comes stock this way (I'm running FP Stage 1 which is 130 on the outters and 127.5 on the inners-Stock is 122.5 and 125 if I recall). The theory from what I have read is it helps with cooling and my bike runs great. I don't think it's a needed setup on the 600 though. But I'm just guessing.
Re: Carbi Jetting
Posted: Tue Nov 03, 2009 6:33 pm
by Dragon
sweekster wrote:Dragon wrote:Not doable!!
You have to have the same size jets on all carbs...
Not true..for example...the FZR 1k comes stock this way (I'm running FP Stage 1 which is 130 on the outters and 127.5 on the inners-Stock is 122.5 and 125 if I recall). The theory from what I have read is it helps with cooling and my bike runs great. I don't think it's a needed setup on the 600 though. But I'm just guessing.
Hmmm, first I have heard of this.... I may be wrong.
YG/ Razor/ anyone you got any input on this?
Re: Carbi Jetting
Posted: Tue Nov 03, 2009 7:27 pm
by yamaha_george
Dragon wrote:sweekster wrote:Dragon wrote:Not doable!!
You have to have the same size jets on all carbs...
Not true..for example...the FZR 1k comes stock this way (I'm running FP Stage 1 which is 130 on the outters and 127.5 on the inners-Stock is 122.5 and 125 if I recall). The theory from what I have read is it helps with cooling and my bike runs great. I don't think it's a needed setup on the 600 though. But I'm just guessing.
Hmmm, first I have heard of this.... I may be wrong.
YG/ Razor/ anyone you got any input on this?
The carbs do not need to be copies of each other at all,
Due to manufacturing tolerences accomulating each cylinder is an individual as is the pipe from it.we are talking valve opening times / sizes of pillows rounf the valve aslight varience in the duct passed the valve Ad Nausium.
Bearing in mind it stands to reason jettiing CAN be off fro one cylinder to another. Anyone who has synched a bunch of four carbs will tell you that they can vary wildly as can compressions across heads .
Yamaha will "best guess" on the rich side & use blah heat plugs to keep the engine together for warranty after that you are on your own "said very politely with an inscewtable smile ".
Re: Carbi Jetting
Posted: Tue Nov 03, 2009 11:10 pm
by mossy1200
sweekster wrote:Dragon wrote:Not doable!!
You have to have the same size jets on all carbs...
Not true..for example...the FZR 1k comes stock this way (I'm running FP Stage 1 which is 130 on the outters and 127.5 on the inners-Stock is 122.5 and 125 if I recall). The theory from what I have read is it helps with cooling and my bike runs great. I don't think it's a needed setup on the 600 though. But I'm just guessing.
I always thought that the inners should be bigger if your going to mismatch as the inside cylinders run hotter so running them richer helps even the temps.