Carburetor problem

SWest wrote: He said that

I have now read it Steve, a silly mistake by me.

kevski wrote:

SWest wrote: He said that

I have now read it Steve, a silly mistake by me.

That's two silly mistakes! Mine was first....assembling them incorrectly!

I am not sure how this set of carbs could be setup in the manner shown. I may be wrong but the pic appears to show connections for the vent system between #1 and #2 and between #3 and #4. It wold appear to me that the current #3 carb came from a set that made use of connections between all four carbs. As it has an opening for the vent on the wrong side of the carb. Or it could be that the carb currently in the #2 position was ment to be a #4.

Either way something just does not look correct in the pic.

He should post some pics. I'm thinking they might be 29 mm smooth bores. Common upgrade in the day.
Steve

Here are pics of what I have. Hopefully they can be expanded and id's. Also found that I do have air leaks around number 1 & 3 intake boots. New boots should take care of that. Thanks for the help.

From the pics posted they are before the use of the accelerator pump. They have pilot screws and do not have air screws. I did try to enlarge the pic to see if I could read the ID stamp, but could not.

I could certainly be wrong, but to me they are from either 77 or the non emissions 78 carbs. 3 of which are vm26 and one vm28. The pic which shows the engine side of the carbs makes me think they are 26s

Again if you can read the ID stamp maybe able to provide more info.

They are 26mm non vacuum pet cock, could have come off KZ900A4 or ltd, kz1000A1 or ltd, do you know what pilot and main jets you had in them to start with, it cannot be far from right, some changed to the 26mm carbs as they run a bit better at low rev range, that said you need to stop any air leaks and make sure your carbs are clean through all the passage ways, if you have blocked pilot circuits it will not run .

Look like Mikuni VM26SS. The 1976 version had air screws. These don't. The 1977 version had pilot screws, which these have. I'm 90% certain they are from a 1977 KZ 1000. Great carbs!



What needles were in the carbs when you pulled them apart?

As far as I know both '77 and '78 VM26's are identical. That's what these look like to me.

The carb bodies are the same from 1977 to 1978 but internals are different...mainly jet needles and needle jets. Also the size of pilots and mains.

Rebuilders seldom replace the jet needles or needle jets so this is one way (but not the only one) to identify the year.

1977 (A1) O6 needle jets and 5CN8-3 needles. Pilots and mains were one size larger than 1978.
1978 (A2) O5 needle jets and 5DL31-3 needles. 15 pilots and 105 mains.
1977 LTD was the same as 1978 A2.

I have two sets of 26s, both with vac stubs but the pilot jets are physically different and not interchangeable, my assumption is they are for A2 and B2 bikes, it would help if a picture o the insides were put on and main and pilot jet sizes were submitted.

One of the really cool things I've discovered about this site besides the great information is the interesting stories about these great motorcycles. My old 900 holds some really great memories for me and apparently has some mysteries too. Owned it forever, but didn't know my carbs weren't stock. Funny thing too because I bought carb kits for my '75 back in the day and got pissed when they wouldn't fit. I thought the guy sold me the wrong kits. They were for two bolt tops and mine has three bolt tops. It wasn't until you guys schooled my up that I now realize my carbs aren't stock. My apologies go out to the guy who thirty years ago knew what he was doing. The history is, the bike has been off the road since the mid eighties. It was running pretty decent when it suffered some very minor road rash in a slow speed gravel incident and was put into storage. I was thinking about putting it back on the road a couple of decades ago when one of my buddies who had a '76 KZ900 was having his carbs rebuilt and suggested I get mine rebuilt too, which I did. However, it was never started with the rebuilt carbs; life got in the way and it went back into storage until now. My friend doesn't remember the rebuilders name, but what came out of the rebuilt carbs are Mains 102.5 Pilots 15 needles, 5cn7, I don't know if that is what came out of them originally or not hence the mystery. It does start now, but I need to replace the intake boots and would like to get the internals right too. Thanks for the help, I really appreciate it.