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New 660 exhaust?

1K views 4 replies 5 participants last post by  oldskool83 
#1 · (Edited)
I looking for recommendations for a new header and muffler that are some what affordablem and also would i need to rejet the carbs with new pipes and modding the air box. I'm looking because she runs real hot on the exhaust now.

My raptor 2003 660R with Wiseco 11:1 Pro-Lite Piston Kit - 4-Stroke, new aluminum radiator an new Silicone hose, new Wiseco Cam Chain and a Bunch replacement parts.

my local elevation is 489' I'm located in Illinois.

my 2003 600R stock jets are
Jet needle clip groove position,3

Main Jets
Left - 140
Right - 145

Pilot air jets
Left - 80
Right 150

Pilot mixture screw turn out:
Left - 3
Right - 2

Starter jet number - 95
thrtize valve number - 80
 
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#2 · (Edited)
Any good aftermarket exhaust will give what you want - I'm biased towards CTR.

The REAL improvement is then also opening up the airbox and re-jetting. With the open airbox use a Dynojet kit with it's 146 main in the leftL and 148 in the right carb and the DJ needles at 1 or 2 notches rich of center... Mikuni 25 pilot jets with fuel screws between 2.5 to 3 turns out (leave all others stock)- should get you close.
 
#3 · (Edited)
#4 ·
I agrre with everything said about the dynojet kit, I just did this about a year ago on my 660 after adding a k&n box lid and full Yoshimura exhaust. Only two things I would add, read the stickey post on how to dial in your carbs and do as it states, and dont use K&N filters, get the UNI filters. The K&N allow fine dust to get by where the UNI filter doesn't.
 
#5 ·
I put an hmf header on mine. I bought a nice used system off ebay for the header. I sold the muffler for as much as I got the system for due to I hate the noise of hmf mufflers. Then I took a mint fmf q4 muffler off my kfx450r welded a stainless extension bolted it to my bike.I hate noise and noise never made power. I got 14:1 compression for power.

Run open or holes cut in air box, then jet up til poping stops. Not hard.
 
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