JOHNDOE83
07-15-2010, 09:46 PM
Ok, im not %100 sure on why these carbs are so different with jetting?
Fcr, 450r, stock...etc.
I realized this issue just recently, and dont have all the info on why it is the way it is.
With my mods, and a 450r carb, depending on temp, humidity...etc...I can be anywhere from 190 to 220 on my main jet sizes.
I noticed Steve, has a 450r carb 416 bore and a 168 main jet, but a 170 in a stock carb.
Nacsmxracer, has a 175 with a fcr carb, 452 stroker motor.
ericcrip, has a 155 with a fcr, and a 440 with more mods then I do.
I know all machines are different, I can build two identical bikes at the same time, and one will need different jetting then the other.
But heres the weird part, bigger carbs need more fuel, more mods need more fuel and air.
So if honda2003400ex needs a 170 with a stock carb and a 416, but nacs needs a 175 for a 452 stroker with a fcr, but ericcrip only needs a 155 for his 440 and fcr, and I need 190+ for a 440 with a 450r carb, what are the issues that would cause this?
Nacs just got his dialed in with a 175, and honda2003400ex has his dialed in with a 170? So these are actually good jetting settings for these bikes they are perfect for their setups.
So why would nacs need only a +5 increase for a 452, and steve need a 170 for a 416? Just like ericcrip has a 440 more modded then mine, but only running a 155?
So basically, what are the issues involved that would cause eric to need smaller jetting then me, nacs to have only + 5 from steve, and me to need 190+???
I know temp and elevation plays a role, different bikes need different things even with the same mods.
So what am I missing here? Its confusing the hell outa me?
Is the fcr with its setup designed to put out more power at a lower jett setting? why would it need smaller smaller jetting then a stock carb? with my stock carb, I could leave it at 220 main no matter what temps were that day, but with my 450r carb, its sensitive to temp changes?
Is it the slide, needle and accelerator pump that make it different with jetting, I feel kinda lost at the moment?
Carb basics tells me that the bigger the carb needs the bigger the jet would have to be, which works on mine, but it seems its not the same for others that have the same?
Can someone clear this up for me?...trxracer1 and steve Im looking in your direction...lol.
Am I missing a simple explanation here?
Fcr, 450r, stock...etc.
I realized this issue just recently, and dont have all the info on why it is the way it is.
With my mods, and a 450r carb, depending on temp, humidity...etc...I can be anywhere from 190 to 220 on my main jet sizes.
I noticed Steve, has a 450r carb 416 bore and a 168 main jet, but a 170 in a stock carb.
Nacsmxracer, has a 175 with a fcr carb, 452 stroker motor.
ericcrip, has a 155 with a fcr, and a 440 with more mods then I do.
I know all machines are different, I can build two identical bikes at the same time, and one will need different jetting then the other.
But heres the weird part, bigger carbs need more fuel, more mods need more fuel and air.
So if honda2003400ex needs a 170 with a stock carb and a 416, but nacs needs a 175 for a 452 stroker with a fcr, but ericcrip only needs a 155 for his 440 and fcr, and I need 190+ for a 440 with a 450r carb, what are the issues that would cause this?
Nacs just got his dialed in with a 175, and honda2003400ex has his dialed in with a 170? So these are actually good jetting settings for these bikes they are perfect for their setups.
So why would nacs need only a +5 increase for a 452, and steve need a 170 for a 416? Just like ericcrip has a 440 more modded then mine, but only running a 155?
So basically, what are the issues involved that would cause eric to need smaller jetting then me, nacs to have only + 5 from steve, and me to need 190+???
I know temp and elevation plays a role, different bikes need different things even with the same mods.
So what am I missing here? Its confusing the hell outa me?
Is the fcr with its setup designed to put out more power at a lower jett setting? why would it need smaller smaller jetting then a stock carb? with my stock carb, I could leave it at 220 main no matter what temps were that day, but with my 450r carb, its sensitive to temp changes?
Is it the slide, needle and accelerator pump that make it different with jetting, I feel kinda lost at the moment?
Carb basics tells me that the bigger the carb needs the bigger the jet would have to be, which works on mine, but it seems its not the same for others that have the same?
Can someone clear this up for me?...trxracer1 and steve Im looking in your direction...lol.
Am I missing a simple explanation here?