What Jetting With New Port Job

[No Limit Powersports]

Just sent my shee to the porter getting a medium port with the boost ports put in. I live in south east kansas and running a noss cool head 20cc domes, cpi inframes, 4 degree timing, vforce reeds. Right now I am running 340 mains with no air box lid and a k&n any ideas what i need to do after my port job. Also i heard that i need to go down to 19cc domes after the porting but I want to be able to run pump gas?????

[SyNtAxx]

Hello,

 

 

Jetting with a port job is silly, sometimes it changes sometimes it may not. Mine changed big time after my port. I reputable builder/porter should be able to give you ball park figures on jetting. If they cant...they dont get my juggies....

 

Also....when you port you will loose some compression....how much will be determined by how my you were ported and such......You will just have to see what compression you have AFTER you get her back together and do proper break in procedures and all the internals settle in....then you can start to up the compression if you feel it necessary.

 

 

Hope that helps....

 

 

Nick

[Ducman]

Also the static compression may go down but the dynamic compression when running WOT in the power band could go up. Again, your builder/porter should know if the 19cc domes will work w/no detonation and pump gas. I'd guess 19cc domes will probably be OK if you can do it on stock ports and 20cc domes but who knows. The increase in power probably wouldn't be worth the risk.