Pilot jet question

[Guest]

So my GS 1100EZ with 1150 36's and MotoGp Werks pipe stumbles at lauch until about 3k and than it takes of and runs fine. I currently have a stage 3 jet kit in it with 138 mains. I have not replaced pilots which are the stock 47.5's. Cant seem to smooth it out...

[tkent02]

What have you done with the jet needle?

[jwhelan65]

What have you done with the jet needle?

Set on the 3rd notch

[GSX1000E]

Their race can or the street can? Which intake system are you using? Are those main jets dyno jet numbers? Which clip position is the needle jet on?

[jwhelan65]

Their race can or the street can? Which intake system are you using? Are those main jets dyno jet numbers? Which clip position is the needle jet on?

Street can, yes Dyno mains, k&N pods, 3rd position down on the clip.

[GSX1000E]

Keep the stock pilots in there and change the mains from dyno jet 138=130 Mikuni and either install dyno jet 144=135 Mikuni. Adjust fuel screws to suite. See if that doesn't improve things but, I think that you may want to go up even more to a dyno jet 146=137.5 Mikuni.

[jwhelan65]

Keep the stock pilots in there and change the mains from dyno jet 138=130 Mikuni and either install dyno jet 144=135 Mikuni. Adjust fuel screws to suite. See if that doesn't improve things but, I think that you may want to go up even more to a dyno jet 146=137.5 Mikuni.

How do the mains effect the roll on? I had 140 dynos to start with the same problem.

[GSX1000E]

Several other builds that I have seen that are very similar to yours all had at least 135 main jets and 47.5 pilots. A couple had the needles up one more notch. (Down on the jet.) Are you running stock cams?
Have you tried to ask Bill? (Chef )
Heck, I have the same pipe and the same carbs/air filters that I could throw on one of my stock 1100E's and find out. Heck, I even have that dyno jet kit that I could play with.

[tkent02]

I'd try lowering the needles a notch and see what the changes are.

[Sci85]

I'm inclined to go with tkent's suggestion given the little details. However, I think you need to define more clearly what you mean by stumbles at launch. Do yo mean from standstill, at idle? Are you rolling the throttle on or wacking it open? Have you tried both and is there a difference? Is worse or better when the engines cold? And lastly, did it ever run correctly before and if so, what did you change?

[niclpnut]

I had a similar issue on my 1100es. I adjusted the float hight slightly higher (more fuel) and it helped smooth out the needle transition.

47.5 pilot installed clips 2nd notch from bottom
138 DJ main.

Nic

[Carter Turk]

Wife's 1150 has 135 mains (Mikuni) K&N's, third clip on needle, yosh pro series 2 pipe. Not sure on the pilots 47.5? Runs clean and I've never done anything to the carbs aside from cleaning some film off the slides.

Always wondered if the float height is compromised when the carbs sag under the weight of gravity, with no air box to hold them up.

[jwhelan65]

I had a similar issue on my 1100es. I adjusted the float hight slightly higher (more fuel) and it helped smooth out the needle transition.

47.5 pilot installed clips 2nd notch from bottom
138 DJ main.

Nic

This is probably the next logical step

[jwhelan65]

I'm inclined to go with tkent's suggestion given the little details. However, I think you need to define more clearly what you mean by stumbles at launch. Do yo mean from standstill, at idle? Are you rolling the throttle on or wacking it open? Have you tried both and is there a difference? Is worse or better when the engines cold? And lastly, did it ever run correctly before and if so, what did you change?

No changes, fresh build. The bike stumbles between 2-3k, idles fine but wanders up after a ride a mile down the road.

[niclpnut]

If it's pulling 3-4k to redline 3/4 and wot the float height adjustment should help on that needle transition just before.

My fzr 1000 was doing the same thing. Raised the float hight 1.5mm and pulls like a train.

Just readjust the mixture screws once your happy with he float height. Probably won't need them turned out quite so far.

Nic