I counsel the following: do not even consider going to a single carb setup. Period. It will turn your potential sport-bike into a toad. If you want to have low end torque and not be able to rev, buy an older single.
Carb Kits for the Virago
Deep Breaths
Let's try this: Preliminary descriptions and tentative pricing for dual carb kits for the Virago, RH/RJ, and TR1. All kits come with a Mikuni tuning guide. All kits come with two (2) carbs. All fit to the stock air box. They come with all cables. Custom setups, such as with after-market air cleaners, can be provided.
All these carbs shine with a high-compression big-bore, the first emphasizing low-end power. A big bore and perhaps a C05 cam set will have you out-pulling any stock two-valve twins. Going with a C01 cam kit will put you far ahead.
For stock or near stock motors we have a pretty nice little dual Mikuni VM34 carb kit. Seen below, it consists of aluminum flanges, rubber manifolds, two carbs, and a throttle cable. Niche Cycle built the original kit on an XV920R. They put one on a Gen I Virago 750, and found that it worked just as well. They have put a carb sync plug in each flange and included a number of pilot and main jets. However this leaves you no place to plug in vacuum lines for the petcocks. From me, the flanges will have an additional tap with a rubber cap in case you've moved on from vacuum petcocks. These will fit Virago 700s up to one thousands, and connect to the stock tubes into the frame and back to the stock air cleaner. I'm also including a hefty Mikuni tuning manual so you know, if necessary, how to select the right jets and how to install them. The included one-into-two throttle cable is meant for stock bars or lower; like clip-ons. If you have high bars, say so and we'll dispatch everything with a 48" cable.'
- Kit with Additional Vacuum Taps and Tuning Manual
- $500
For built 750s or stock 920s with performance exhausts there is a kit I'm putting together. Two Mikuni TM38-85s outfitted out the same way as the 34 kits, and hook up to the stock air ducts, a throttle cable, a handful of jets and a Mikuni tuning manual. Remember to tell us if you have high bars so we send the right cable.
Note that for smoothest operation you must have the intake ports opened to fit the carb flanges.
- Kit with Additional Jets and Tuning Manual
- $700
Extreme builds need monstrous intakes. So coming soon is the introduction of dual Keihin FCR41 kits for those who had their engines bored to at least 99mm; this represents the 1065cc kits for the 920/1000 and the 1155cc kit for the eleven hundred.
Keihin kits are a lot of work to develop from scratch. The carbs must be chosen from a variety of configurations. The spigot that connects the carb to the intake flange must be picked; the same with the intake bell on the back. Even the cable hanger on the carbs must be chosen to provide the optimal alignment. It will likely be different on the front and rear carbs. Cables need to be made. Throttles with enough 'throw" must be used. A choke cable kit must be installed on each carb; actually, this is tentative: we may be forced to use the down-draft versions of these carbs. No configuration of down-draft carbs have choke circuits. Then a baseline jetting must be found, and a lot of jets and such must be included for those having custom pipes bent up. As it stands expect a final price of about $2400 for the complete kit. Remember that these are 41s, NOT 39s.