[250ARRR]

04 CRF250R,
Just installed FMF 4.1 with megabomb.
My question is: Should I jet it?

Started it up first time and it idles fine, with slight bluish/white smoke. (but it hasnt been started in a month so I am thinking thats normal) After about 4 minutes of idle, the head started to glow hot at the front. (I shut it off immediately.)

Started a second time on the first kick, with a regular idle. The header did not glow this time.
I didnt get to ride it yet. But I will Sunday...or should I?

Follow up questions:
Even if it runs fine, do you guys suggest jetting anyways?

And is it normal for exhaust headers to get glowing hot at first? When the bike was brand new, the stock exhaust did the same thing and never did it again after.

[zak13]

when ever you change sumthing engine wise it is reccomended to change jetting i mean whats the worst that can happen your jetting was already spot on then you have to re install the stock jets and from what i hear the headers are supposed to glow

[fbr]

Jetting Center:

We know how difficult jetting can be sometimes, that's why when we test our exhausts we also adjust the jetting to see what works best. Sometimes stock jetting works fine, other times a slight adjustment is needed. Here is what we've come up for in our area and is a great starting point for you as well. There are way too many variables in jetting to give you a recommendation that works perfect. Use these specs for a reference to help aid you with your specific bike. We developed these specs with a 32:1 fuel to oil mixing ratio of a 50/50 mix of race fuel and super unleaded, 0 - 1500 ft altitude at 70 degrees outside temperature.

Your choice: HONDA --> 2004 --> CRF250R

Jetting Information
Main Jet: 160
Pilot Jet: N/A
Needle: STOCK
Needle Position: 3RD
Power Jet: N/A
Air Screw: N/A
Fuel Screw: 2

Comments: "250ARRR" - I just installed the same (single silencer) system on my son's '07 CRF250R. His bike with an otherwise stock engine did not need any re-jetting just a little tweak on the fuel screw. We shaved 2 pounds converting from the dual silencer OEM system and his bike is quieter and has improved low to mid-range power. The info above is copied and pasted from fmf's website. I think it is safe to assume that you disregard their blurb about 32:1 gas:oil ratio when referencing the "F" models.

[250ARRR]

Yeah I saw that on thier website. I was debating seting that up. But I rode today and it was fine. More power with a smooth delivery. I can wheelie much easier too. Im happy.