A little more jetting help from you guys please.

[rigger]

Looking for a little advice from you guys out there. If you could just point me in the right direction with a little jetting, that would be great.

First, here is what I currently have...
36mm PJ carb
open air box w/ UNI filter
FMF pipe and a mild motor with a little higher compresion
running on race gas

Currently have a 160 main
Needle is dropped all the way down, #1 spot
42 pilot
air screw is now 2 turns out

This is how it runs now...
Starts great, idles great, you can blip the throttle and it is just fine. If you dump the throttle to it, it will choke down and if it makes it through it, then it will run like a champ.

When riding, ( this is just down the street and back, I have not taken it out on the trails yet ), it has very little bottom end, and the more you run up the throttle, it will then hit and run out just great. It just has that bog from about 1/8 - 1/2 throttle.

I am assuming it is running fat in that area. I played with the needle and when I dropped it all the way, It seemed to help some.

Do I need to go to a smaller pilot, bigger needle smaller main?

The next size down main that I had was a 152 and it did not seem to help out so I put the 160 back in it.

Any advice would be great. I was going to order some jets to play with but thought I would get your thoughts on it before I went and ordered some.

Thanks guys, as always yall are a big help.

[86 Quad R]

have you made sure that the float is set properly and is shuting gas off completely. sounds like the pilot is about right. could possibly be a lil phatter. what needle are you running. may need a leaner series.....

btw: have you done a leak down test to ensure that the crank seals are good or the center case gasket hasnt blown? juss a thought

[rigger]

Good thought on the gaskets and seals. All that should be good. All gaskets and seals are new. Crank seals are new.

I will have to go pull the needle and see what it is. I was kinda thinking it may need a little leaner needle as well.

I was just looking on line for a jet kit for this Keihin 36mm PJ Carburetor and really did not have much luck finding one. I looked on the Duncan Racing site and did not see one listed for it. It is one of their carbs. Guess I could call them and see what they have for it.

[86 Quad R]

fwiiw i would take anything for granted when it comes to ffresh seals en gaskets. i've pressure tested engines as soon as finished a build just to have them leak around the center gaskets ect.

if all else fails.... try These (http://www.carbparts.com/keihin/katv.htm) guys for parts. :cool:

[rigger]

Here are the needles that I have.

The one that is in the 36mm right now is has DG on it.
I have another one out of a 34mm carb that has DGH on it.

I do not know if the DGH might be a leaner needle or not.

[RyanWsly]

2nd the float height, make sure your reeds aren't hanging open just a fuzz, make sure the spring loaded retainer for the needle is holding it snug in the slide, then try to go leaner with you needle, IMO doesn't sound like it needs re-jetted till you get this little demon figured out, and I pressure test engines with new seals after assembly also. I believe Duncan Racing give you directions on how to build one I believe, lots of ways to make them though, fairly cheap if you use your imagination.

[rigger]

I called Duncan yesterday since it one of their carbs any way and the guy I talked to told me I needed a DGJ needle. He said both of the ones I had were way to rich. So I ordered one from them to try. It was only like 5 bucks I think for the needle and I got a couple of pilots to try too.

So when I get them, I will give them a try and see what happens.

[RyanWsly]

Bet that will help you out a bunch, had a YZ250 someone had changed the needle in, messed with the jetting forever and never could get it right, fine on top but way rich on the bottom and mid-range, like you I finally ran the numbers and they had put some funky needle in it, took me while to figure it out though.