XS650 Mikuni VM34 Carb Kit - Which one to buy?

peterg

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Hello

I'm been a member for a bit more than a year now but this is my first post. There is an incredible amount of info on this site and I've made use of much of it.

I have a 1980 XS Special that I bought in stock condition last June and spent the winter modifying it to make a Brat-ish bike. I've tried to get the stock BS34 carbs in good working order but after spending this summer re-jetting, adjusting float height, replacing gaskets, replacing the float valve assembly, replacing the throttle shaft seals, replacing boots, etc., etc., etc. I'm ready to buy a VM34 kit. There are so many suppliers of these kits I'm a bit overwhelmed and not sure of which one to buy. The suppliers I've looked at are:

T.C. Bros.
http://www.tcbroschoppers.com/xs650-mikuni-vm-roundslide-34mm-performance-carb-kit.html

Niche Cycle Supply
http://www.nichecycle.com/ncs/mikuni/carb-kits/yamaha/ncs235-yamaha-xs650-70-79-vm34-carb-kit.html

Cognito Moto (from the description wording it might be Niche's kit)
https://cognitomoto.com/products/mikuni-vm34-carb-kit-for-yamaha-xs650

Cyclexchange
http://www.cyclexchange.net/Yamaha XS650 Carbs Page.htm

Dime City Cycles
https://www.dimecitycycles.com/vint...ikuni-34mm-carburetor-mikuni34mm-001-235.html

650 Central
http://www.650central.com/

I know that there are other kits available through ebay and XS650direct (Canada's Mike's) but, based on comments I've read on this site, I'm not exploring them as options.

Some vendors are forthcoming about which components they install (DCC) and some are not (TC Bros).

Some kits have flanges with spigot indents and matching rubber connectors (Niche). Others have straight hose (DCC) or what looks to be stock boots (Cyclexchange). Is the flange type and connector type even important?

I'm middle aged and just got my licence last year - speed is not what I'm after. Just having carbs that don't idle erratically and that perform consistently at all speeds. RPMs and throttle positions is all I'm looking for.

Your thoughts on which kit is best would be greatly appreciated.
 
650 central gets high praise from this forum. From my personal experience I went with Gary from Hoos racing. No kit you buy will likely be set up perfectly, it’s gonna require some fine tuning from you. Having said that, Gary asked about climate, engine etc and prejetted mine pretty close. Like I said, some work will be required on your end, but I found his customer service and experience with the xs to be exactly what I was looking for.
 
As figure8 said 650 Central or Gary Hoos. I have bought VM36's from 650 Central and have only made minor changes from the as supplied settings.
I doubt you will be disapointed if you go with either of these suppliers. Choose the one nearest to you.
 
Thanks for the comments so far.

Hooser (Gary?)

Is the only difference between the kits as I've noted below?

34102 VM34 mm Carb Kit #1 - generic filters
34103 VM34 mm Carb kit #2 - K&N filters
 
Thanks for the comments so far.

Hooser (Gary?)

Is the only difference between the kits as I've noted below?

34102 VM34 mm Carb Kit #1 - generic filters
34103 VM34 mm Carb kit #2 - K&N filters
Yes sorry, Gary is who you’d talk to at Hoos.
 
Thanks for the comments so far.

Hooser (Gary?)

Is the only difference between the kits as I've noted below?

34102 VM34 mm Carb Kit #1 - generic filters
34103 VM34 mm Carb kit #2 - K&N filters
I used different intakes also on the 34103, it is more set up for a full bore 750, that needs to breath better. It will not fit in the space of a stock 650.
 
Peter, some of the vendors you listed are fine sources for chopper/cafe racer/bobber bling but don't have a clue when it comes to tuning. If you want grief and extra expense, buy cheap from the bling merchants. If you want quality, buy from 650 Central or Hoos Racing; you'll be dealing with guys who know how to tune and will give you expert tech support after the sale.
 
Grizld1 - good point about the bling merchants.

I have already received great customer service from Hoos Racing and I'm not even a customer yet! I'll probably go with their kit.

Just out of curiosity has anyone ordered a kit from any of the others I mentioned?

Photos of my bike below for anyone interested. The pipes are ceramic coated stock and the pods have been replaced with Uni filters in an attempt to better the BS34s' performance.

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IMG_0486.JPG
 
First, in response to Griz. These other vendors are certainly not cheaper, unless you mean in terms of what there doing.

Second to OP. I’m gonna say it because if I don’t someone else will. Very nice looking bike, but I can almost guarantee your carb problems correlate to those pods. They don’t look like Uni pods, though I could wrong. Many here will advise against those tiny pods. They heavily restrict the carbs ability to breath correctly. You’ve been on TC Bros site, they sell foam Unis that I had good success with on those exact carbs. Some will advise using a large pod, they worked fine for me.

Should you not be able to be swayed, get ahold of me. I may be interested in taking those stock carbs off your hands.
 
Yeah, figure8, I'm referring both to cut-rate vendors and vendors who maximize profit with cheap tricks. Example: some of these characters install #15 or #17.5 pilot jets to compensate for the Q2 needle jets and 6DH4 needles that come in the carbs from Mikuni. Sure, Sudco uses #15 pilots; they work in the Sudco setup because Sudco uses rich 2.0 slides along with leaner needle jets and proper needles--a very expensive setup. Retaining the factory generic needles and needle jets and fooling around with the cheaper main and pilot jets won't produce results that are anywhere close to satisfactory. A working baseline has been posted in the VM section of the XS650 Garage USA Carb Guide and repeated here in post after post with warnings about the frustration and expense in store for anyone who buys from vendors that are not known to be both competent and honest.

Good catch on the pods. I can't count the number of warnings 5twins and I have posted about those cone filters. As the old timers say down here in So. IL, "Them as won't hear it is gonna have to feel it."
 
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Peter,

I can also recommend 650 Central's kit.

It is a bit of an old school experience, as you have to phone your order in....This is a good thing though.

When I placed the order, I spoke with Michael for the better part of an hour about all things xs650 (not just carb related).

When fired the bike up for the first time with the new carbs, it came to life on the third hit of the starter button.

No kit is going to be 100% plug and play. However, Michael provided some good baseline jetting to get started.
 
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Retired gentleman - thanks for the compliment. I learned how to wire from building guitar effect pedals and tube amps as a hobby.

Re pods: sorry my note wasn’t clear. The pods shown In the photos have since been replaced with Uni filters - PK-92s. The Uni filters helped but not to any great extent.
 
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Where did you get the power splitter under the seat. Is it fused?

Grizld1 - good point about the bling merchants.

I have already received great customer service from Hoos Racing and I'm not even a customer yet! I'll probably go with their kit.

Just out of curiosity has anyone ordered a kit from any of the others I mentioned?

Photos of my bike below for anyone interested. The pipes are ceramic coated stock and the pods have been replaced with Uni filters in an attempt to better the BS34s' performance.

View attachment 107783 View attachment 107784 View attachment 107785 View attachment 107786[/QUOT
 
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