Talonhawk,

What jetting are you using on your carb? I am trying a 34mm pj keihin carb on my friends Trailblazer with the HPD trail pipe,porting and slip on filter. I need to be close. It came with a 152 main and it wont run. I cant tell if it is to rich or lean. Are mikuni jets and keihin jets different and do they go with the same size increments. Is a 150 mikuni jet the same as a 150 keihin jet? Anyone have any info? Thanks!

 

Kurt, the Mikuni numbers are much larger than the Keihin. For instance a 300 Mikuni would equal a 165 Keihin, dont know if that's true size comparison, but you get the point. A 152 main seems small to me. I run the dual 35 PWKs on my Banshee and I have 165 mains in it.

 

Well I guess Bubba297 answered that but I'm running a 160 main
and a 38 pilot the needle is on the middle postion.
So you say that your friends quad won't run or won't stay running?

 

No it wont stay running. When I looked at the main jet on the keihin it looked alot bigget then the mikuni jet. I could be wrong. It will idle somewhat ok but when you give it gas it bogs really bad. I didnt think the 152 would be to small but I dont know much about keihin carbs

 

If it bogs bad I would say it would be lean before being rich. They should try and run but "blubber" if they are rich. I would start with the needle clip in the next to last (4th) position and go to a 160 main jet. Ohhhh. I forgot too, I run a 48 pilot jet. Dont worry about what pilot it came with for now as long as it tries to idle. Adjust the air screw for the best possible idle then work on the needle and main jet to start with. Just remember that jetting figures are the same, bigger number is richer and smaller numbers are leaner.

 

I would say that if it won't stay running or idle then its a low
speed circuit problem. Has the choke been checked or adjusted
and what about the pilot screw or jet?

 

I was told by keihin that the stock 152 jet is like running a mikuni 230 jet. Way to rich for his application. We then dropped down to a 120 main and it runs real good. Still a little rich but we are in the ballpark. Now We need a smaller pilot jet. Stock is a #58 and am going to try a #35.