switching from fattys to CPIs jeting?

[supernova_64]

I have just purchest a new set of CPI inframes to replace my FMF fatties. About how much will the new pipes effect my jetting. The reason im asking is i only have 2 sizes bigger than what im runnig now and dont want to have to buy more jets for my stock carbs that i wont need when i get 33PWk's this winter. The bike is stock with v force 3's, no air box, noss head with 22cc domes, and +4 timeing plate. Also this winter i am going to build a 4mm cub motor will these pipes work well or should i have gotten Shearers. thanks

[yamaha11]

I have just purchest a new set of CPI inframes to replace my FMF fatties. About how much will the new pipes effect my jetting. The reason im asking is i only have 2 sizes bigger than what im runnig now and dont want to have to buy more jets for my stock carbs that i wont need when i get 33PWk's this winter. The bike is stock with v force 3's, no air box, noss head with 22cc domes, and +4 timeing plate. Also this winter i am going to build a 4mm cub motor will these pipes work well or should i have gotten Shearers. thanks

 

i have a 4 mm with herr juggs dune port with cpis and 35mm carbs and it ripps hard as hell

 

[2003LimitedBanshee]

I have just purchest a new set of CPI inframes to replace my FMF fatties. About how much will the new pipes effect my jetting. The reason im asking is i only have 2 sizes bigger than what im runnig now and dont want to have to buy more jets for my stock carbs that i wont need when i get 33PWk's this winter. The bike is stock with v force 3's, no air box, noss head with 22cc domes, and +4 timeing plate. Also this winter i am going to build a 4mm cub motor will these pipes work well or should i have gotten Shearers. thanks

 

I've got a set of CPI's coming tomorrow from BoostedRex and he recommended I go up 4 main sizes from my current jetting. However, I am running T5's currently which seem to like more fuel than the FMF's (SST's are about the closest), so I would guess that you are going to be more than that. I would guess, depending on your elevation, that you are probably right around 300 right now? 290-310? So with that, based on the recommendation given to me, I would put you somewhere around 340. I would buy at a minimum, a size on either side of that. At a couple dollars a jet, my opinion is that is far cheaper than leaning it out, or looking like the two stroke guys that give us a bad rep and fouling plugs all day.

 

[supernova_64]

thanks, i just didnt want to go buy 10 bigger sizes before i go out to ride, if i wouldnt need them.

[BellicoseBanshee]

Also this winter i am going to build a 4mm cub motor will these pipes work well or should i have gotten Shearers.

CPI or Shearer pipes work well with a cub. :thumbsup:

[J-Madd]

I'd leave the fatty's on a stock unported motor.