Name Those Carbs

Okay, the block checks out as stock 650. So, I guess plan A is still to clean the stock carbs and see what happens when I put them back on. I figure even if it had some kind of bore kit, there's no need for the 29's, right?

The biggest puzzler is still that the guy who had the bike on the road a few months ago (registered and inspected) says the 29's were on it when it was running right. He told me I should put them back on. I got the impression that he was being completely honest with me about everything (good and bad). He sold the bike (w/ clean title) for a very modest price and handed me an extra set of carbs which turned out to be worth a small fortune. I'm sure he wasn't telling me any stories.

Thanks,

Barry

It may be that the 29s were rejetted for the 650. Also, keep in mind that even with the 650 cylinder block, it's still possible that someone could have gone with bigger pistons. maybe not, but you never know.

TexasKZ wrote:

Mikaw wrote: Sense the mystery has been solved can I ask a could carb related questions. Can someone post a quick description of the different types of card. I.E. what is VM. What is smooth bore, what is VMSS I know this can get very in depth really easy but I hear all the terms and have no idea what they mean.
RS?
VMSC?
Square bore?
Smooth bore?
RS flat slide?
They list seam endless. Maybe a new posting would be better?

RS = Mikuni flat slide carbs. These are modern mechanical slide carbs
VM = Mikuni round slide, smooth bore , mechanical slide carbs. No throttle valve. Factory installed on Kawaskis in the 1960s and 1970s.
29 smooth bores = high performance aftermarket VM carbs.
CV carbs = carbs with vacuum operated slides and cable operated throttle plates . Used on modern bikes until replaced by fuel injection.

Thank you. Clears it up a lot.

The VM29's will need KZ1000 intake's and those need the bolt holes slotted to fit the 650/750 head
Ask the dude if he has the big intakes if he don't or says you don't need them he's lying about them
ever being on your motor,

I'm not being a dick but the Vm29's are not a pull the VM22's or VM24 and stick the VM29's on swap.

zukdave wrote: The VM29's will need KZ1000 intake's and those need the bolt holes slotted to fit the 650/750 head
Ask the dude if he has the big intakes if he don't or says you don't need them he's lying about them
ever being on your motor,

I'm not being a dick but the Vm29's are not a pull the VM22's or VM24 and stick the VM29's on swap.

Thanks, Dave. That's very useful info. I guess it's time to stop trying to figure out what may or may not have happened in the past. Something obviously doesn't add up. I'll just clean the stock carbs and sell the 29's.

Thanks again,

Barry

Do you know for sure your engine is stock and it does not have a piston kit? I would make sure of that before selling the 29mm

IMHO I think the O/P would be better off running the small carbs. sell the VM29's and put that money back in the bike.
Me I'd sell/swap the 29's and find a set of VM26's and a good pipe.

YUP
Steve

Overkill on a stock KZ650. The engine won't be able to take advantage of the carbs' flow capacity. You will end up jetting them down so much they won't really be running as they could if on a larger engine

The way it was explained to me, imagine drinking using a drinking straw or a hosepipe. Small bore carbs=instant throttle response

Big carbs take much longer to get the engine vacuum 'signal', unless you are genuinely racing this using rpm power all the time and drag starts you'll find appropriately sized carbs much nicer to ride on the road.

God I love bad info.
I'll say this one more time you WILL NOT need to jet them "down"
Running VM29's on a 650 cc motor you will get a very weak idle signal caused by slow air flow
therefore you need to go up on the pilot jet to help pull fuel.
I don't give a damn what people say changing "jets" will not change the air flow through the carb.

If I'm wrong then why does Sudco the main importer for mikuni carbs list a 25 pilot as a starting point for a 750 cc motor ?

You're right Dave. In the chart below, it calls for a 17.5 pilot on my bike. It won't run with that. I have 70's in there now and 65's were a little lean. Maybe when I bump up my compression, I can lean it out more. I have 2.0 slides.
jetsrus.com/carburetor/carb_mikuni_VM33_...oded_view_parts.html
Steve

Look at the bottom of this page do the hand thing and move the pic.
universalprintingco.com/pageflip/162087-Sudco/#174/z