Help identifying carbs

So i just found an '81 650 CSR with low K's and am going to spend the winter going through. Anyway, I pulled the carbs off and I can't seem to find any information about these. More specifically, what's with the external accelerator pump?
I would like to remove the whole accelerator assembly and run the carbs without. I also want to run pods and as you can see these pump jets are mounted right in the intake. The stock intake boots barely fit on there.
What would be a starting place for needle height and main jet size if I was going to remove pump?

They are the stock Mikunis 22s I believe. Also some drilled the venturi and put hoses in for equalization. Most have had pods? The pumps are the chokes, not an accelerator pump.

R

You can see right in the center there is a diaphragm pump with fuel supply from 2nd carb from right and pumped to those inlet nozzles. I also have 2 other kz's I've rebuilt. My 79 1000 has the vm 29's with accelerator pump style built into carbs. I actually turfed those and found some 29's from a gs750 that are perfect. Anyway, I am familiar with the choke circuit etc. And these measure out at vm 24's. Just never seen or can find any info online about this external pump circuit.

If they came from the factory like that taking off the pump would be a mistake. Slide cutaway would need to be changed as well as needle jets, needles and possibly emulsion tubes. On the underside of the slide is a number (1.5, 2.0 etc.) With pods the accelerator pump would be needed even more.
Steve

Those are not the stock carbs for the 81 650-CSR & that is not a stock accelerator pump. The pump nozzles aren't stock either. I'd guess that someone added the pump to a set of 70s VM24s. maybe 77 or 78 .

The 81 csr came stock w VM24 carbs w accelerator pump. The pump is on the #2 carb bowl & the nozzles are smooth. The pump is actuated by a mechanical linkage to the throttle pulley.

1979 VM24 w AP. the 81 csr are similar.

Never too smart to learn something new... R

xxsierraxx wrote: You can see right in the center there is a diaphragm pump with fuel supply from 2nd carb from right and pumped to those inlet nozzles. I also have 2 other kz's I've rebuilt. My 79 1000 has the vm 29's with accelerator pump style built into carbs. I actually turfed those and found some 29's from a gs750 that are perfect. Anyway, I am familiar with the choke circuit etc. And these measure out at vm 24's. Just never seen or can find any info online about this external pump circuit.

If you have vm29's with an accelerator pump, they're rare and worth some coin. Vm29's were an aftermarket only performance type carb, no bikes were fitted stock with them. 79 kz1000 had vm26 or 28 pumpers stock. The 26s are considered untunable.

I have had several gs750s, none have had 29's on them. Not saying it doesn't happen, because it does; but every gs750 I have had still wore the stock 26 mikunis

Your right, the ones I had on my KZ1000 were vm 26's. Very hard to tune. Yes' I did find a set of vm26 from as gs750. Bike runs perfect now. Anyway, I thought maybe someone had added them so I'll take the accelerator pumps off and try them out. They have 105 mains so they should be okay and both pilot and air are adjustable so I should be able to tune em..

Wait... What's hard about tuning 26mm Mikuni carb's. I don't think I've had any trouble.

Let me clarify, the vm26 PUMPER carbs are considered by some (ahem wired george) to be untunable

martin_csr wrote: Those are not the stock carbs for the 81 650-CSR & that is not a stock accelerator pump. The pump nozzles aren't stock either. I'd guess that someone added the pump to a set of 70s VM24s. maybe 77 or 78 .

The 81 csr came stock w VM24 carbs w accelerator pump. The pump is on the #2 carb bowl & the nozzles are smooth. The pump is actuated by a mechanical linkage to the throttle pulley.

1979 VM24 w AP. the 81 csr are similar.

I have a set of VM24 pumpers for a KZ650 that are exactly like these, I've never seen the OP's set up before. I have VM24's without a pump on my KZ650B1 and it runs great, so they could be tuned accordingly, if things like the slide cutout and the needles are different that could be an issue as those are not parts you can just buy like the jets.

If they are Mikuni's chances are you can get slides needles and needle jets from jetsRus. Running slightly lean makes more power and the pump makes up for the flat spot off idle or during the RPM range. My 33's were fitted with one and the emulsion tubes were drilled so they would run lean. It was missing when I got them. No amount of jetting would cure the flat spot. I had to solder the extra holes being parts aren't available anymore. Lucky for me the guy couldn't drill in a straight line so it was easy to close the ones he did. I have 2.0 cutaway slides like the early Z1's. What I need are 1.5's like they did on the later models.
Steve
God I hate this machine!