carb identification

After doing a little work I've come to the conclusion that My bike is a mut. I think I have parts from 73, 74, and 75 Z1s. Not to mention the 78 front end I put on it. Anyway I have had a lot of problems getting the carbs tuned and want to make sure I using the correct specs. Can anyone tell me what carbs I have based on these pictures or tell me how.





Post edited by: bharper6649, at: 2006/08/26 08:14

Post edited by: bharper6649, at: 2006/09/20 18:05

Your carbs appear to be Mikuni 28 mm carbs that were used on the Z-1 from 72 to 75. In 76 they went to 26mm carbs for the KZ900

Any suggestions on jets? Currently I have 115 mains and 20 pilots. I didn't put these in, so I'm not sure of the logic behind the combination. The bike has pods and 4 into 2 exhaust that is pretty open(very little baffle). I raised the needle to keep from fouling plugs, but really want to get it setup correctly. Any help would be appreciated.

75 Z1B VM28SC: rejet to #120, #17.5 5J9-3 - Please limit the number of pics in a post as I never was able to sit still long enough for more than one to fully load. Some of us are on dial up connections! Thanks wg

Sorry about the pics. I've been on broadband so long I never consider speed. I will keep the pics to a minimum in the future. I'm off to buy some jets.

Thanks.

Not a problem... when I download pics, it occurs at 3KBS... posts with LARGE or many small pics are painful.

BTW: The pilot jets on your carbs are the same as on the later VM series carbs and not the same style as the 73/74 pilot jets. Your #20 pilots probably won't hurt but you had best have a good spark or your plugs will soot.

The main jet switch helped a lot. I'm still trying to track down the smaller pilots. Maybe I can get this thing screaming before winter.

Thanks for all the help!

wiredgeorge wrote:

75 Z1B VM28SC: rejet to #120, #17.5 5J9-3 - Please limit the number of pics in a post as I never was able to sit still long enough for more than one to fully load. Some of us are on dial up connections! Thanks wg

George,
After talking with Jeff from Z1 enterprises we figured out I have the older model carbs. Does your recomendation change for the older carbs?

Thanks

Bryan

Hello Bryan, I'm very confused with your carbs. The pilot jets you showed in the picture to me are the early style with just 6 bleed holes - yet your carbs are the later Z1 carbs...

Not sure what to think.

The carbs pictured appear to be Z1B carbs (1975). To verify, there is an ID mark inside the red circle on the flange.
2170=1975
1473=1974
1470=1973

The bowls are totally different and not interchangeable from the 75 to the earlier models so I think you will see a 2170 ID mark.

The stock pilot jets on EITHER the earlier Z1/Z1A carbs or the later Z1B carbs will accomodate the use of pods and aftermarket pipes as they are relatively rich when added to the relatively rich jet needles/needle jets used in those carburetors. In other words, if you have the stock (#20 on the Z1/Z1A) or #17.5 on the Z1B variation, it doesn't matter much... you will be OK... Note that I suggested reclipping to the 3rd slot on the jet needles if you have the Z1B carbs.

Jeff.Saunders wrote:

Hello Bryan, I'm very confused with your carbs. The pilot jets you showed in the picture to me are the early style with just 6 bleed holes - yet your carbs are the later Z1 carbs...

Not sure what to think.

I'm confused as well. The more I work on the bike the more confused I get. I have parts from at least 3 different years. Its no wonder I cant get it running just right. As for the carbs I can't find the ID George mentioned. I can't be sure I'm looking in the right place. Can you point me in the right direction?

It is a small marking on the carb flange where it enters the bracket that holds the four carburetors.