Has anyone used these carbs before?

[ATXzombie]

http://www.speedmotoco.com/mobile/Product.aspx?ProductCode=029-314#PhotoSwipe1460244904362.
They are vm34 carbs. How do they run over stock? Are they worth the money ?
Thanks

 

[5twins]

Many use the VM34 carbs but maybe not from that particular seller. You have to watch where you get them. Many don't come set up properly for a 650 which means you would have to spend additional money for different jets. These are custom high performance carbs so you usually have to do a little of that anyway, but if you get them from a known reputable seller, they will at least be very close to right. Also of note, if you read the fine print on that link, you see that price is for carbs only. You would need to buy manifolds, air filters, and the special 2-1 throttle cable. That could easily add another $100 to that price.

 

[figure8]

Agreed, look up Hoos racing. He'll set up those carbs for you based on your bike mods and climate.

 

[grizld1]

Click the Tech button, go to the carb reference thread written by INXS, and find the link to the VM section of the XS-650 Garage USA Carb Guide. You'll find a baseline jet list there.

Gary Hoos of Hoos Racing and Michael Morse of 650 Central are both expert tuners and ethical vendors who provide solid advice before the sale and tech support after. If you buy for less you'll get less.

As far as performance goes, let's be real clear. With a stock motor, a nonvacuum carburetor is going to provide throttle response that's a little bit quicker than the stock carburetor with vacuum actuated slide, but that's about it; it's not going to make your Bruce Banner stocker split its paint and morph into the Incredible Hulk. The VM's are advantaged when it comes to modified motors because they have more tuning options than the stock BS-series carbies and because modified motors can take more advantage of the improved breathing that results when you take the throttle shaft and plate out of the middle of the venturi.