pwizl
XS650 Addict
Which Mikuni carbs for an XS650 are non vacuum or straight pull?
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Non vacuum carbs
- Thread starter pwizl
- Start date
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- Tags
- build carburetors engine
DIRTY DOG
XS650 Guru
vm round slides:d
All stock carbs were vacuum carbs.
You need to go aftermarket for the VM carbs.
Leo
You need to go aftermarket for the VM carbs.
Leo
pwizl
XS650 Addict
Which are easier to work on, set up, and tune?
I think the stock carbs are. But then again I haven't worked with any of the VM's. If I did I might have a different answer.
Leo
Leo
The question is, easier to set up and tune for what? And let's add to the list of Mikunis. If you can do some fabrication, you can bank a pair of Mikuni TM33/8012 or TM36/68 flat slide 4-stroke pumpers or you can split two carbs out of a bank of RS34 or RS36 flat slide 4-stroke pumpers. You can also jet a pair of TM34 flat slides, although, like the VM's, they're not dedicated 4-stroke carbs and represent a rather dated design. In my experience the 4-stroke pumpers are the easiest to dial in because component effects are much more tightly isolated. Run some searches and you'll find plenty of information on all of the above, no point repeating it here.
pwizl
XS650 Addict
It's just a stock rebuild for a motor for street cruising and freeway use. I'm just looking for the easiest most reliable option and I've always liked the non vacuum option for simplicity sake. My only experience with carbs is on cars, this is my first foray into motorcycles. Grizld1 do you have any picks of banked 4-stroke pumpers or a thread that talks about it? Is there a particular bike that has those carbs, TM33 or TM36 that you're talking about? I don't mind doing a little fab work and actually enjoy it. Thanks
Those are all aftermarket carbs, they're not OE on anything, though several variations of the VM series appeared on Yamahas, Suzukis, and Kawasakis in the '60's and '70's. There are some good threads on the RS-type carbs here and at XS650 Garage, but you'll have to dig to get them; try "RS34" and "TM36/68" in your search terms. There's a lot of work involved in setting up the dedicated 4-stroke pumpers (throttle shafts have to be linked on TM pumpers, fabricated for proper spacing on the RS carbs, etc.), so if you're just interested in replacement carbs for a stock motor they're really not worth the work and expense; a pair of VM34's or the general purpose TM34's will be much simpler to install, though a bit touchier to tune. There are many threads with baselines and tuning tips, do some searches and you'll find plenty of information. 650 Central has the best combination of service and price available for the VM34's--Michael Morse's tech support comes with the purchase, and that support is the best there is. There are several fine threads by mrriggs and others on tuning Kawasaki Ninja500 carbs for the XS650; it surprised me to find out that their center-to-center intake distance is the same as the XS650, 120 mm. They're vacuum carbs, but a later design, and they should do very well.
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pwizl
XS650 Addict
I thank you very much sir. I'll give 650 Central a call.
