sons 397 rappy. carb question

[Dr. Gerbik]

sons raptor has a 397cc stroker kit. stage 2 jets (what ever the hell that comes out to) a uni filter and GYT-R pipe. Bike was running a little rich untill i replaced the air box lid with an open one and removed the spark arrester/ opened it up at the tip. Question is. do i need to rejet for the slightly lean condition (and hopefully regain some bottom end torque) or can I simply raise the main jet one notch on the slide and cure the problem? thanks in advance:tup:

 

[beastlywarrior228]

Whats your main jet and pilot #s

 

[duneracerweston]

Do a plug chop but idought its going to hurt it any

 

[Dr. Gerbik]

Whats your main jet and pilot #s

155 i wanna say...... what is a plug chop?

 

[Dr. Gerbik]

the plug is on the lighter side of tan as is. could use just a tad more fuel. the power band is all in the top end now is the main difference. is that just how it's gonna be with this engine combo? Or can he gain some torque back on the bottom end?

 

[beastlywarrior228]

Wow 155, that seems like a lot for a stock exhaust. Course if it has a stroker i could see maybe. Go up 1 on the main and see what happen possibly the pilot too. These quads usually arent too hard to get right in jetting

 

[Dr. Gerbik]

its a Gyt-r pipe with no spark arrester and cored pretty much. not sure if the gyt-r is much better than stock on this bike or if it's all bling. either way its cored and the uni has no top on it. confirmed 155 and it's on the ragged edge of being a tan plug..... just lost all his torque on the bottom end

 

[Dr. Gerbik]

go up a jet size or lift it up a notch on the slide?

 

['00 WO-YA!]

2 different parts of the carb & 2 different effects to the powerband. Moving the needle costs you nothing to try but it has the biggest effect on mid range throttle. I'd give it a shot & look at the plug after a few hard runs, moving the needle will directly effect how far it seats into the main. Try richening the pilot as well, don't make all the changes at once though. You can adjust the pilot out w/o removing the carb so start there.

Consider that your bottom end power loss may be associated with messing with the exhaust & it's back pressure & not necessarily b/c it's slightly on the lean side.

 

[duneracerweston]

Gytrs eat torque I will admit but they are screamer pipes and thats how I like mine thats just my opinion though