Tips on ZRX-1200 carb swap?

[Bonz]

Thanks for the link to the other thread, I had not found that one in my searching around the forum.

I'll keep you posted. I think I'll run the pods on the ZRX carbs, since I have them on the ZRX already. The ZRX runs flawlessly, so I don't see why it shouldn't translate over to the XS, other than the jetting, etc.

The ZRX 1200 is going to get the carbs from a Kawasaki ZX11/ZZR-1200. This is the equivalent upgrade to putting ZRX carbs on the XS, especially with the mod's done to the ZRX and the ability for it to breathe with the pods and full exhaust system.

[Outlaw4shrt]

anyone know if you can use the needles from a mikuni dynojet kit with the keihin's? I bought a jet kit for my stock mikuni's a while back and used the 138 mains from the kit in the cvk's and I'm curious if I can use the needles too. they are the same length, just thinner at the bottom, and height adjustable.

[Bonz]

Needles should work with whatever brand jet you have. The taper of the needles can dictate you go smaller or larger in jet size to work the best, the taper enters in to the clip position you end up with as well for best response, idle, driveablilty, etc.

Probably some experimentation in your future to dial it in, but otherwise should work in the grand scheme of things.

[natemoen]

I would not think so. The dynojet needles would have been made to work with the emulsion tubes in the mikuni and not the ones in the keihin's.

[Outlaw4shrt]

I would not think so. The dynojet needles would have been made to work with the emulsion tubes in the mikuni and not the ones in the keihin's.

could the taper make that much of a difference, they are the exact same length? I sadly know squat about carbs. the needles are for midrange tuning correct?

[natemoen]

Taper is a big part of how the needles work. It is one of the main ways that fuel is metered out into the engine.

[Outlaw4shrt]

Taper is a big part of how the needles work. It is one of the main ways that fuel is metered out into the engine.

good to know, thanks, I guess I'll just leave them as they are.

here are a couple pictures of my attempt at the vacuum advance. wasn't paying enough attention and went too far with the drill bit and hit the butterfly. I think it still seals ok at idle so I'm going to leave it as is because the vacuum advance seemed to work fine, but I wouldn't mind some feedback on if that's going to be a big problem or not. thanks.

[TADracer]

I would think you are OK as long as you never move that butterfly. The hole is in the correct position as it should be barely closed when the throttles are at idle so you get no vacuum signal at idle, metered vacuum at a crack of the throttle (which is where you are at cruising speeds) and no vacuum signal at WOT.

[Outlaw4shrt]

I would think you are OK as long as you never move that butterfly. The hole is in the correct position as it should be barely closed when the throttles are at idle so you get no vacuum signal at idle, metered vacuum at a crack of the throttle (which is where you are at cruising speeds) and no vacuum signal at WOT.

well that's good news, thanks.

[natemoen]

Might be ok. I would do something to smooth out the grooves you make in the butterfly thought. The rough edges might do something to F up the air flow, but might not cause enough to be an issue.

[Outlaw4shrt]

Might be ok. I would do something to smooth out the grooves you make in the butterfly thought. The rough edges might do something to F up the air flow, but might not cause enough to be an issue.

I'm nervous about it, but I'm also hesitant to take any more metal out of the one that's damaged. I'm not sure how hard it would be to just get a new butterfly but that's probably what I will end up doing eventually.

[TADracer]

Looking at the picture I am of the mind that it will be OK. The two holes under the center of the butterfly are the pilot system ports and there should be a third hole (not visible) just past the butterfly. So any imperfection by the vacuum advance hole should not come into play at all by the pilot holes as the throttle is opened.

BTW, next time you do this....prop the butterfly open with a small stick of wood so the drill does not come close to the edge of it.