mikuni vm 26 rebuild

I just got my fathers 1976 900 LTD and I am now in the process of restoring it to original specs.

It came equiped with (4) Mikuni VM26SS carburetors.

On these carburetors what should be replaced if it has been parked for 22-23 years.

I assume that I should replace the upper gaskets and the bowl gaskets. I should probably replace the jets and the needles. If I am missing anything please let me know.

anyone out there who has worked with either these bikes or these carbs before I would like to hear from.
Any additional experience to pass on helps.

Thank you

In my opinion guys go way overboard on rebuilding carbs. Gaskets don't go bad for the most part even if sitting 25 yrs. Jets don't go bad, needles don't go bad. Yes, jets get plugged from stale gas, but otherwise don't go bad. Rubber hardens, but what rubber is there really? The rubber between the main jet tube and carb that don't do didly squat and the rubber on the air screws that if left alone will work just fine without replacing. If it was me, I'd just do a clean of the carbs, then sync and ride on down the road. Just me probably, but I've yet to rebuild a carb yet in probably 20 KZs and 300-400,000 miles

Everyone's got an opinion. Personally since you are going to go to the trouble to take the carbs of the bike which is kind of a pita anyway, I would just order new carb kits from Jeff at Z1.

www.z1enterprises.com/detail.aspx?ID=41

When you go to tighten the screws on the bowls and such don't reef on them with the good old screwdriver. It will bend the carbs and then you will get a leaker. I just got some new T fittings for my set because I have a leak there. Might want to check that out as well.

If fact, it sounds like you are new to KZ's . Bookmark Z1enterprises. They will be a great resource for you when doing work on your bike. Great selection of parts for these old dinasours.

Good luck and congrats on the bike.

I'd be willing to bet that you need to replace the carb holders .
They get old and crack and the rubber that seals against the block goes bad.

Chances are you won't need to replace the jets. Along with what's been said about the rubber manifold Carb holders. I'd suggest that you get replace the "T" fuel fittings between the carbs. The rubber on them gets hard and don't seal as well leading to leaking. ZI Enterprises has them too. In a pinch you can wrap them in teflon tape, but if you're tearing the carbs apart for a good cleaning replace them now.

Bill

ejshotgun wrote:

I'd be willing to bet that you need to replace the carb holders .
They get old and crack and the rubber that seals against the block goes bad.

+1. I just received new ones for my '79 1000, I had a vacuum leak on 2&3.

I've been monkeying with the carbs on my bike for awhile now, and oddly enough, they are '76 KZ900 carbs. I would take the top and bottom covers off, remove the fuel outlet screws (the big brass ones in the bottom bowl) and start cleaning. Leave the floats alone as much as possible! I tried setting my floats, but I though I was dealing with '79 carbs at first, which have a different float setting. Clean the fuel bowl out, remove the jets (main and pilot) and spray them clean. I also removed the air idle screw and cleaned that passage out. Make sure all orifices are flushed and you can see carb cleaner coming up out of the main body when spraying.

I just replaced the top and bottom gaskets (the old ones ripped). I also replaced the o-rings on the fuel outlet screws, as they were rotted.

Post edited by: arozanski, at: 2007/07/09 15:34

Thank you all for your advise.
I have decided to only replace the ruber t fittings and the rubber carb holders. allong with new upper and lower bowl gaskets.

Thank you