Raptor Runs exteamly HOT!!!

[Mcsommerfeld]

Please help me!  My raptor runs very very hot!  The headers glow about 2 min after starting.  It has a full HMF exhust and a K&N air box, those are the only mods I can see.  The carbs are still stock jets, what do I need to do?  Please help me!

[Spartan]

glowing headers are normal. you need to run bigger jets to richen it up more

[Mcsommerfeld]

All of the jetts right now are stock, what should I got to? and which jetts should I be changing?  Just the pilot jets? or everything?

[Peelz]

glowing headers are normal...yes....but....doesnt mean it's a good thing.

SPartan is correct. AF screws could be off as well.


THose mods...you need bigger mains for sure. Maybe even pilots/and or adjust the needle clip position. 155 and 160 jets would be plenty rich. 25 for the pilot.

do not buy a jet kit IMO. stock is 145 and 150? get a 155 and a 160. Then you have 3 possibilities and maybe a 25 for the pilot.

for reference:

I had HMF with K&N oem replacement filter for first mods and my jetting was: 150/155 and moved the needle clip down one, effectively making the needle spring lighter, and allowing full fuel flow sooner.

I like 660 questions.

basics of jetting a rappy

http://www.raptorsource.com/forum/index.php?topic=20.0

http://www.raptorsource.com/forum/index.php?topic=8.0

[Mcsommerfeld]

Peels, Thank you!  I called the dealership and they said about the same thing. I am taking the Pilots up to a 25 and going back to stock on the pipe and air filter.  Do you think that will cure the issue? or should I change out the main jets to?

[Mcsommerfeld]

Can anyone tell me what the needle clip should be set at when in a stock position?  Right now they are both set as low as the can go, is this right?

[Peelz]

Peels, Thank you!  I called the dealership and they said about the same thing. I am taking the Pilots up to a 25 and going back to stock on the pipe and air filter.  Do you think that will cure the issue? or should I change out the main jets to?

absolutely change your mains first before pilots. you are running lean with a full exhaust. Need more fuel asap

I bet go up 1-2 sizes

left main is one smaller than right on rappy 660. I bet you 150 left, and a 155 in the right will do it.

oh just read second post there.

Why going back to stock? Loved the HMF on my 660.

If you are stock exhaust and intake, BIG mains not necessary. needle is in the middle stock???...its been awhile I forgot sorry. Thats done more by feeling. If your bike stumbles when you mash the gas...you will want to move the clip down one, which makes the needle come up out of the jet sooner, adding fuel faster.

[Mcsommerfeld]

Peels, thank you agian!  Very helpful!!  I am going back to stock as a starting point, this quad is in rough shape, and I need to know exactly what I am working with to get running correctly.  Plus, I like the quiter stock exhust a little better, I know, I know..im getting old right?  Thanks for your help, im running up to get new jets as we speak!

[Peelz]

cool good luck. those two links there I posted will tell you all you need to know. Especially the one with the tear down of the carb....HUGE help to me.


and lets not talk about being old. thanks, I dont like thinking about it 

[kincerjustin]

In my opinion because Ive been working on my Raptor jetting quite a bit.Dynojet kit is the way to go.I have a full Yoshimura exhaust with umf airbox and k&n filter.Purchased stage 2 kit for about 65 bucks.Did the kit myself and my 2003 660 runs really good.Instructions are very easy and it comes with pictures too.

[Mcsommerfeld]

Thank you to all who answered!  Espically QM, I put in the Vitos kit and she runs like a GEM!!!!  Dont even need the choke to get er started!  No more bright red headers and plenty of power!!!  Thanks you again!!