I had race porting done on my 98blazer hpd agressive clutch kit,hpd pipe,35 flat slid from hot seat.the motor makes a sound like this babababbbbbaaaaauntil full throttle.I live in northern missouri if that helps.is it my needle or my pilot? I also have a 35kehin carb from hpd that has never been run and it wont fit any ideas? thanks

 

Well, I'm certainly glad this post isn't what I thought it would be. I thought for sure I would read that you were sticking jets in your ear until you found one that fit tight. [img]i/expressions/face-icon-small-tongue.gif[/img]

 

I can't tell by ear. But try running the engine at 1/4 -1/2 throttle
for about two minutes and then hit the kill switch. Pull the plug
and check its color. Tan to light brown is what you need. I think
you may need a bigger pilot jet. The Keihin carb body is larger
than the Mikuni. Is the Keihin hitting on the top of the Trans. case?
I have the Keihin on my quad and I had to file the top corner off of
the transmission case. Do you have the split throttle cable? Your choke
could also need adjusting. You should have 3/16 - 1/4 inch freeplay at
the chock lever.

 

I bet you could adjust that out. Try moving your needle clip up a groove and see if that helps. I don't know about your jetting thou. I can always tell how mine is jetted. I can hear it when it goes lean but I know my quad more intimately than my wife.

 

if it sound like fat cow yell,that mean you definitively on the lean
side and must richen the jetting,check spark plug color for proper jetting at all throttle positions, DO NOT WOT if the engine is yelling like that,sometime the piston turn blue and dindn't crack suddenly,you might check compresion PSI when engine is cool down next time you go ridding instead to back home walking.