Best carbs you can buy?

[scabber]

The CVK has vacuum actuated flat slides one difference,

 

[Signal]

I agree with Scabber. Have GPZ 500 CVK carbs on my road bike and love them. They replaced VM 36 carbs. Would not hesitate to use the CVKs again.

My previous post was intended as a presenting options post, not a recommendation and continuing in that line MMM from 650 central told me he has used Amal MkII carbs to good effect.
From a quick scan of Amal's info it looks like they are available in a smooth bore version. 2900 series (34mm), 2000 series (36mm), Smooth bore (34,36 & 38 mm)

http://amalcarb.co.uk/mk-ii-concentric-series.html

The good people in the UK are trying to work with Amal to get a bolt on ready to go kit. In reality no carb kit can ever be such but they should at least address the major issues.

http://xs650.freeforums.net/thread/64/amal-carburetors-replacing-bs34-carbs

 

[hotdog]

IMHO, get a set of vm34's and put the extra coin into some headwork, shell #1 Cam and intakes, some better valve springs and either a707/750cc bore.
All that will be close to what you'd spend on a set of fcr's and you'll have a great responsive bike that will be a complete blast to ride.
Like griz has already mentioned get Craig's guide you'll see you don't need $1K carbs to make power.

 

[aldo5468]

+++ on the Keihin CVK's - there's a very long and detailed thread on retrofitting them to Yamaha 650's that includes an awful lot of tuning experience to get you very close on your first combo of needles, pilots and mains.

 

[Liftedzuki]

Being the Keihin CR is a "performance version" of the CVK, has anyone used the CR?

VM, CR, or CVK seems like the most practical.

 

[grizld1]

The CR is emphatically not a performance version or any other sort of version of the CVK. The CR is an old design: manually controlled round slide carburetor. The CVK is a second generation vacuum carburetor: light, vacuum controlled flat slide, fitted as OE to a number of bikes, a significant improvement over the older Mikuni BS34's and BS38's that are OE on the XS650.

If you think the CR is a practical option, check your resources (wallet and ability). Fit and finish is beautiful, tuning includes the secondary main jet typical of Keihin carbies. But you're either going to do a lot of fabrication (throttle shafts, choke actuators, brackets) or pay through the nose for custom work, and there's no data pool re. the XS650. The CVK, on the other hand, offers bolt-on fitment and plenty of information from experienced hands who've tuned them.

 

[Liftedzuki]

Google search shoes people we're replacing their cvk to cr on their ex/gpzs so i took it as an upgrade ovdr the cvk. They were pretty vague and didn't mention the round vs flat side difference.

The cr is $500, and I can fabricate anything I need. But I would have to learn to tune carbs, I'm an efi guy (rock crawler background) so suck at carbs.

I was under the impression that the cr was very similar to the cvk.. I don't mind spending money just not 1200 unless it's going to be an significant upgrade.

 

[grizld1]

Had a look at the Power Barn site, and the price (less than $500/kit for the EX500) surprised me; I figured it would be more. Most of the fabrication is done in their kit. Since the EX500 head has the same port spacing as the XS650, throttle shaft and clutch actuator will be fine. The only other fitment issue would be mounts; I don't know the spigot OD on the CR's. OE BS34 boots might work, but do the homework. CR's jetted for the EX500 should get you close enough to fire up for tuning; the old 4-valve twin isn't going to be a lot thirstier than the newer 8-valve twin in spite of the difference in displacement. But when you're dealing with aftermarket carburetors, no matter how carefully pre-jetted they are, you're going to need one of three things: a lot of luck, a lot of patience and research, or a lot of hands-on help, paid or otherwise.

 

[Liftedzuki]

I'm going to get it "running" then take it to a pro.

I'm not a carb fan (I'm an offroad 4x4 guy, aka efi)

I want it to run like a top,not my experiment lol.

I'm going to buy jbm intake boots BTW.

 

[Liftedzuki]

Well sob. I ordered JBM intake manifolds and went to order the carbs from power barn today, CRs are all on B/O til mid spring.

So I guess I buy CVKs or wait.

 

[peanut]

might be worth considering Amal Mkll concentric carbs they are high performance carbs and very reasonably priced
http://amalcarb.co.uk/mk-ii-concentric-series.html

 

[CDNTX650]

Take it to a pro to tune.....good luck. There is alot of good threads on "pro carb tuning" done by "bike shops" all over this place.

 

[Liftedzuki]

http://www.ebay.com/itm/05-EX500-ex...ash=item1c5fb195a5:g:iJQAAOSwT5tWOPTz&vxp=mtr

Well with the CRs on b/o, I will run these