I remember somewhere on here where someone had a surging bike and it was electrical, the fix was to add a ground wire to your harness. Sorry I don't remember the specifics but maybe someone who was having those problems will chim in as it was the fix they were looking for.

 

Is the BB needle a fuel screw, or something else? When I compared my stock to the kouba fuel screw, they looked identical on the business-side of things. It's interesting that your other fuel screw would cause a surge at higher rpms but idle okay, given that the fuel screw affects only the idle/pilot jet circuit.

 

This has been very helpful. As someone mentioned, the Kouba t-handle does have the same shape as the stock fuel screw, so that should be ok. I spoke with my mechanic, and he said it's most likely the main jet, like most of you guys thought. So tomorrow we will put in the 130 main, and go from there. It's the biggest one I have, so we'll try it, and if it needs more, then I can order some other sizes. We will also check the fuel lines as suggested. When we put the IMS tank on, we routed one of the lines above the frame (between the frame and tank). I didn't think it looked right, so when the mechanic put on the 351, I asked him to route it below the frame. Well, when I got the bike back, I found that he had also routed it above the frame. It's probably not an issue, but I will change it just in case. Plus I think it will eliminate a possible chafing issue down the road. And if those things don't work, then I'll keep the grounding idea in mind. I hope to get it dialed in this weekend or next, since I'm scheduled to head out on a short trip in early November. I can always ride my Husky, but I'm really wanting to take the KLX on a trip for the first time.

 

Fuel screw; it came with the one pictured and one longer with a T[pin] handle.
It seemed to run fine in on and off throttle situations and just bogged on a long up hill pull above 6000 RPM with a load. Like I said I was running with 525 KTMs and some 650 KLRs. All I changed was the fuel screw?

 

Just to update...We installed the 130 main jet this weekend, and it corrected the surging issue at higher rpms. I'm a little irritated at my mechanic, because when he installed the 351 kit, I gave him the 130 main and told him that's what Bill Blue had recommended (Bill said I should go up two sizes on the main and one on the pilot from where I was currently). He didn't install either, just left the jetting the same, although he did raise the needle. So I paid him probably an hour, for what? Oh well, probably should have just done it ourselves in the first place. Now I'm wondering if I should have put the 40 pilot in too, but it seems to be running pretty well. It's not 100% perfect, as it does have an occasional stumble, but then it did before as well. The power feels good, so I'll ride it for a while and then reevaluate I guess. Anyway, thanks for the help.