Ok heres the deal. My buddies and i got together this weekend to do some trails and messin around on the quads. Well my one buddy picked up a new Z400 and just piped and filtered it and wanted to see how fast his was compared to my Raptor. Well I killed his Z400 easily. Then another buddy lined up with his ported shee. I beat him too but it was pretty close. Then my brother lined up with me on his Raptor with the exact same mods as mine except his is using mikuni jets and i am running a Dynojet kit. Well He spanked me pretty hard! By like 3 quad lengths. The bad part is that i am a better rider than he. Before i put in my Dyno Jet Kit i was faster than him cause i have a better riding ability. Now after i put this Dyno Jet kit in he spanked ME!? Whats the deal? I tuned the kit and and have the jetting spot on. I jetted his with the mikuni jets and it is spot on. Why is his faster? We weigh the same. and everything. Guess i am taking out my Dyno Jet kit and selling it. That was realy depressing. But i guess it made my brothers day.

 

When is the last time you adjusted your valves? It makes a difference.

 

Are you running an air box lid? What are the mods for both Raptors?

 

What altitude were you at? I have a fishy feeling that the Dyno Jet Kit can't be tuned correctly for altitude.

Every time I go above 5000ft I can't seem to get the jets right. If I get the top end correct the bottom and mid are so rich you can't drive it. If I get the bottom correct the top is so lean it doesn't produces any power.

Of course at sea level I can get it spot on and kill the stock jets all the way up. I'm going to try changing the pilots the next time. Maybe that will get the low/mid range leaned out.

Maybe I can find a dyno up high somewhere and figure out exactly what is going on. Fuel Injection would really help.

 

I adjusted my valves about 10hrs ago. Both Raptors are running with the airbox lid off. I tried it with it on and off and couldnt notice a difference at all. My brothers raptor is running a procuircut slip on and Prodesign proflo with a foam filter no lid. Mine is running the same but with the Dyno Jet kit. I rode his and i could definatley feel a power difference. His has alot more top end and mid range pretty much the same low end. ours are both 02's bought within a week of each other. I am not too happy. The jetting is on according to the plug. I talked to CT about this and they said the dyno jet kits are good for low but stock jets are better for top. Especially with CT's needles. I have a feeling that they just want me to buy their carb kit. If i cant come up with a good way to make it run better the dyno kits going in the can and i am going back to stock jets.

 

Do a carb swap just to see. Then go from there. Dynojet works!

 

Well as soon as i get a chance i am going to change back to my stock needles and mikuni jets and set mine up like i set up my brothers. I'll keep yah posted on what i find out. I will also check my valves to see if they are still right even though its only been 10hrs since they were adjusted.

 

If you are on the recommended dyno-jet settings with the air box removed, I suspect you are rich on the needles. Do you have an ever-so-slight engine shutter when letting off the throttle when on the needles? Mine did this after air box lid removal.....I wound up having too drop my needles 2 notches too clear this up.....with improved drag results + the front end is easily lofted to clear obstacles on the trail again!
When I removed the lid, I jetted up too 148-150 (from 146-148) and picked up a solid 5 lenghts in a couple hundred yards. I have probably picked up about another 3 lenghts since I got the needles dialed in. Seriously.
If you gear your Raptor up, it will be quicker too.

 

mtecate... I agree with your results, the Dyno jet kit gives good mid response but does not come close to the top end that stock Mikuni needles/mains can give. Problem is, the 1/4-1/2 throttle pos is a little hard to dial in with stock Mikuni parts & lid removed-good luck!

 

there is a trick to getting the stock needles set right so it runs good. You just put one needle a click higher then the other that way it splits the difference of moving both one way or the other.