cpi pipe jetting

[rmkboxer]

 

 

I was talking to a friend who built my motor today and I asked him about the jetting differences between the t5 and cpis and pro circuits and cpis since I have seen my buudies run rich on the top end after switching from the pro curcuits. he asked me why I thought I needed to jet up and I figured more air more fuel. but that is not the case it is that the cpis burn more efficiently then the others so you may not need to jet up and may need to jet down he told me about having to jet way up for fmf pipes and they are not efficient at all. hope this helps explain it for you. It made sense when he told me

[AKheathen]

yah, that makes some sense. i had to jet way up for my pro-circuits, going from my old fmf gold series, which are verry similar to t5's. like 6-7 sizes.

[No Limit Powersports]

Do a leak down if your buring oil its sucking air. You need to get that thing sealed up before you do any jetting.

[Burt Reynolds]

With pipes you have to consider how much gas and air is being pushed back into the cylinder by the exspansion chamber. Cpi's might need smaller mains because they work more efficiently and therefore require less gas and air to do the same job

 

I personaly just switched from toomey t5's to CPI small bore inframes,and i run 33mm pwk carbs,

I had to jet down from 165 to 155 for the cpi's,and went from a 45 pilot to a 42 i think(not positive on the pilots but i know i had to go down) I was surprised to but thats just the way it works with some setups. My Cpi's wont even let my bike rev out all the way with 165 mains and 45 pilots,runs like crap,

But when i put the 155 mains and 42 pilots in it freakin screams. I also had to lower the needle one clip.

Edited July 16, 2009 by Burt Reynolds

[volcrano]

With pipes you have to consider how much gas and air is being pushed back into the cylinder by the exspansion chamber. Cpi's might need smaller mains because they work more efficiently and therefore require less gas and air to do the same job

 

I personaly just switched from toomey t5's to CPI small bore inframes,and i run 33mm pwk carbs,

I had to jet down from 165 to 155 for the cpi's,and went from a 45 pilot to a 42 i think(not positive on the pilots but i know i had to go down) I was surprised to but thats just the way it works with some setups. My Cpi's wont even let my bike rev out all the way with 165 mains and 45 pilots,runs like crap,

But when i put the 155 mains and 42 pilots in it freakin screams. I also had to lower the needle one clip.

dude im with u.i also had to do that-i went from 270s to 250s,had a 32.5 pilot-im at 25 now and still need less-like 22.5s and i think my needle also needs leaned 1.i just wanted to fuck jetting and ride for once.i adjusted timing from +4 to 0 and top pulls way harder.raced my buddy on his fresh unported 421 cheetah and beat him until i started missing shifts.granted his is unported but i had a woody.i knew i was right going leaner-at top end with 270s that thing would gurgle like crazy.its sweet now-have a slight gurgle at 1/4 throttle but pilots and needle will help that.i appreciate all the help from u guys-u my niggaz lol.