What position is the needle set at? Did this always do this or just start doing this?

 

Really the first time to try it. Middle position. [img]i/expressions/face-icon-small-wink.gif[/img]

 

i put a 39pwk on a few weeks ago,and with a 38 pilot jet there was a slight bog on takeoff.i switched to a 35 pilot and the bog is gone and its more responsive..

 

do you have the trail (torquer) pipe? or topend(speed) pipe? i have heard that the topend pipe will produce that bottom end lag...

X

 

If he has a true HPD racemod then he will have the race pipe. It is totally different fron the top and trail pipe. The expansion chamber is all in front of the frame unlike the other pipes with the chamber running along side.

 

Ron, you may want to try the hpd almond primary. Its what I run. It will raise your stall speed considerably. Maybe with s58s or 55s depending on your gear, weight ect.
I used to run the blue and didnt like it as much

 

THat's an awful big pilot jet for only a 172 main, I think your pilot needs to come down some!

 

Man I didn't see that on the pilot jet. I would think that would be way too high as well. I'm running a 35 pilot and it does great.

 

i've end up to 55 pilot jet on mine race mod,check your primary
sheaves clearance,it might not exceed .015-.020

 

My bike did not like the blue spring, the violet worked great. If a spring change doesnt fix it then put on a new belt and the problem will go away, trust me.