Motorcycle carbs?

[avw1973]

The weather has been too wet and cold. So, time to waste. I have an EMPI Sporster I am going to start working on. It will have a 1200 engine. My question is if I could fabricate a manifold and linkage, could I use 2 motorcycle side draft carbs? Old Amal or Bing. Any thoughts? Thanks!

[whozawhat]

find a pair of carbs that are of the proper size to feed 1200cc, watch out for manifold icing in your manifold design, consider carbs with chokes for easier colds starts, if your sportster is going off road often you may consider a large single center mount to avoid excessive sloshing in the float bowls

[Geeto67]

A couple of thoughts:

most motorcycle carbs are cable operated, so I don't know that you would need a linkage so much as just run two throttle cables to the gas pedal and make sure the cables are linked up. Motion pro can sell you anything you need to make custom cables, and they can even make custom cables for you if you provide them measurements.

you are going to want to keep motorcycle carbs synched up. this requires using a synch gauge on a vacuum port and adjusting the slides, air bleed, etc....the hardest thing is going to be a vacuum port, so make sure your carbs have one (some bikes have it in the head) and getting the hoses long enough to reach two side by side gauges.

If I was going to use a motorcycle carb, I would look for a CV type carb. Why? CV carbs use engine vacuum to adjust the slide, meaning the engine draws in the fuel/air it needs based on vacuum pressure. This increases drive-ability and part throttle operation smoothness. Most modern carbed harleys have CV carbs and they can be had fairly cheep used but are 40mm and might be overkill for a vw engine. an XR400 honda has about the same size piston as a vw and depending on the year uses a 32-34mm carb so that might be a better fit.

[BFB]

i had thought about mikuni carbs for a vw, even talked to a buddy of mine thats into older bikes and hed said they make splitters for the throttle cables and i believe they are adjustable ?
also somewhere in the classifieds i think i was a set of aircraft intake manifolds which either go straight forward or straight back and would be perfect for side draft carbs

[sallyandsean]

I did one a couple of years ago using a ZX9 single carb. Worked well but used a lot of fuel.

[rayjay]

I would look at a stock carb off a Harley twin. They are Keihin CV carbs and should be a good size. I worry about having enough accelerator pump but it would be a fun experiment.