I need info from anyone with a zilla with a 39mm keihin PJ carb. Tell me your slow jet size and air screw setting. I've been trying to keep an air screw adjmnt of between 1 and 2 turns but I think that this only applies to mikunis. I have presently a 58 slow with maybe 3/4 turn out on the air screw and still runs rich!!! Please help[img]i/expressions/face-icon-small-smile.gif[/img]

 

Gee Storm, it doesn't look like anyone knows what there carb is jetted at!![img]i/expressions/face-icon-small-disgusted.gif[/img]

 

a 58 pilot? I'm running a 38mm keihin with a 62 pilot and i'm not running rich. This is on a lt250r at 700' elevation.

 

Geez I can't figure it out...it runs too rich at idle and low RPM!!!!!! The CR500 bike has the same carb and it runs a 55 slow in stock form, so I figure mine should be relatively close?

 

I think you need to go larger on the pilot. here is a thread where another lt250r dialed in his jetting and he is running a 65 pilot click

This info isn't for the zilla but out of curiousity how do you know you are running rich? I thought mine was running rich with a 55 pilot but it turned out that it was lean

 

It'll start to smoke if I put put around for too long with my kid on the bike or if idling too long! It will bubble bubble bubble when I open her up to WOT and clears up after a couple of high speed runs. It's not burning trany oil or antifreeze. I had gone up on the slow jet to 68 with worst results. Defenately runs much better with a 58 jet in there but still a bit rich. I have a 55 jet on order. I'll try that next!

 

so what is a good carb to get . i am running a stock one with jet changes, i would like more power. of course,,, lol i see mikuni 39mm 0r 40 for $160...

 

Hello, you might check out the duncan racing website here there's an article on jetting a keihin carb. For what it's worth I am going to be putting a 39pwk on mine after I get the top end back on and trinity told me to start with a 60 pilot.

Good Luck

 

i need to know whaty carb would be good to get now that im over bored and have a good pipe