Mixed Up The Carb Internal Parts - Advice?

Trying to revive an 81 KZ750-N1 Spectre 4-cyl shaft drive that sat unused for a few years in a garage.

This is the first multi-carburetor machine I've worked on. All my other projects have been dirt bikes and ATVs with single cylinder engines.

So in my ignorance I did the unthinkable: removed & disassembled the carbs, and put all the brass jets together in the cleaning solution. Didn't even stop to think that each carb had been tuned specifically with its set of jets, and that slight differences in the brass pieces could cause the carbs to change their performance or tuning if put back together with mixed-up former sets.

So Now I've reassembled them, having no idea exactly where the pilot jet in cylinder #3, for example, might have come from. Same for all the parts except the little plastic plugs – that's because they're numbered 1 through 4.

Here's my dilemma: should I assume that I've dorked up the whole previous synchronization/tuning, and just start over from scratch with the default pilot screw turns out and a feeler-only measurement bench-sync on the carbs' butterflys (I don't have a vacuum meter)?

Or should leave the butterflys where they are, and try resetting the pilot screws to their former positions, just in case it might still run ok that way?

If I had vacuum measuring tools I'd just set it all to initial defaults and synch the carbs properly. But I don't. I'll have to do al my tuning “by ear”.

For what this is worth, I believe the carbs are stock, Keihin 34mm CV diaphram type. Primary main jet #65, secondary main jet #90, pilot jet #35, float valve brass seat insert #2.0, slide needle # N1 0A.

Advice, comments? The carb's still sitting here on my living room desk until I make my decision on how to proceed. Thanks -Robert

Does not matter what jet came from where. You wouldnt want to change any other parts but those dont matter.

The float valve and seats are matched sets and should not be interchanged, not so important on which carb they from, just that needle and seat stay a pair.

[.

I already mixed up all the parts. No telling which part is from which carb. I cleaned & polished each part. The float valve's needle is the type that has a rubber tip and none of them had that worn-out groove, they all look pretty good. Also saw that someone previously used the wrong size flathead screwdriver on some of the slotted brass parts and boogered up their slots, so i repaired the damage as much as I could.

My first thoughts were "A #90 jet is a #90 jet... shouldn't matter which carb it's from..." but then realized that slight size differences, times multiple parts, times four carbs, might add up to an overall tuning fail.

Anyone know offhand the default number of turns out for the mixture screw on this carb (I had to drill and pull the caps to get at these screws). When I removed them, the 1-2-3-4 turns out setting were 2-1/4, 2, 2-1/4, 2-1/8. Not sure if I should go bac to the same settings or if I should instead go to a standard default.

Like the guys above said it should not matter about the jets. as long as all primaries are the same # you are good. Same for the secondaries and the pilots.

I'm not sure about the seats (float valve needle seats) either. In my Kiehins these are not removable and they are not matched with the float needles but it sounds like yur carbs are different.

You may find that with the floats themselves mixed up that the fuel service levels are different across to bowls and I would suggest using the clear tube method to check the fuel levels in the bowls. I learned this that hard way after mixing up floats :laugh:

Regarding the air mix screws the spec is 2 turns out from lightly seated.If the bike ran well at the 2 1/4 setting then perhaps go back to there. Not a big deal as easy to adjust.
Good luck

Thanks. I have the carbs back together now and will probably put them on tomorrow and give it another try.