I put on my sparks exhaust, did cam mod, and modified airbox. I put in an adapter with a K&N. I started with a 170 main and a gytr needle in the 3rd clip and ran it. It ran awesome except there is a hesitation right when you hit the throttle. Do I need to go up on my pilot or what. Also I did a wide open jetting run and checked the plug and it appeared white so I went up to 175 and ran it again. It is still not getting brown around the electrode. Do I need to richen up the needle next or go up more on the mains. It still ran crisp with the 175, no bog on top end at all. What should I do?

 

Sorry, this is on a YFZ 450

 

Did you put in a larger pilot or turn the idle mix screw out any?

 

No do you think I should go up a size on my pilot.

 

Hey man, cool bike!!! You need to go up on your main, needle and pilot..Get the next 4 sizes richer and work your way down until it dosn't bog..then do a plug check. With all your mods, I think you can still go up way richer. If you are doing a plug check and it is white, you are lean.. Go up on everything and work down until it doesn't bog, then do a plug check and fine tune from there. I'll keep checking here to see how its coming along..Sounds like with your mods, that engine is starving for fuel!! And power!!! Good luck man, Frank.

 

After more riding I have actually gone down to a 170. I had some misses when I would get on it hard so I had to back the fuel off. With a 170 it runs dang near perfect. Sparks is running a 172 in them at sea level so I should be pretty close considering i live at 4500 ft. The thing absolutely rips.

 

Hey man, cool! Where do you have the needle clip? Maybe you are lean on the clip...

 

On the 3rd setting on the gytr needle, I think I am going to try the stock one on the 6th clip.

 

I'm at 5200 feet and when I went to Glamis i had to jet up 3 mains on my raptor so you might still be fat on your mains


Pat

 

I ended up with a 170 main and the gytr needle on the 4th clip and it runs great. I will go up to a 175 when I get my vp ultimate 4 fuel.