New project:Adapting motorcycle Throttle Bodies, this should be "interesting" :) Options

[Mueller]

The cost of aftermarket throttle bodies is way up there, the bottom of scale we have the CB Performance units which are about $250 each and the rest are easily 2X that about.....

so I swung by the motorcycle salvage yard in Fremont today and picked up these beauties (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

45mm at the butterfly....they taper down to 42.5mm at the bottom...

includes a nice TPS and injectors...I doubt the injectors flow enough, but who knows, I'll find out once I get the specs....

no idea of what bike they came off of yet.....price was $125

top view:

[lapuwali]

Mike

Are those grooves in the TBs for O-rings. Maybe you could cut a seat in the manifolds and seal them with an O-ring. Use the studs for some sort of clamping rig. Then maybe some selective port matching.

Dave

Not really an O-ring (putting on my "worked on bikes for 15 years" hat). Bike intake to head manifolds are usually just rubber (or rubber-like) castings, with a lip machined into the inside to catch that groove. I haven't worked on bikes since EFI became commonplace. Those TBs look exactly like a typical set of carbs on any of a number of inline-4 bikes. There are (were) only two manufacturers of carbs on the Japanese bikes: Mikuni and Keihin. I'd be willing to bet money that one of those manufacturers made these TBs.

It would be interesting to know what the flow rate on those injectors are. I'd be willing to bet a set of injectors from a 750-1000cc bike engine would actually be adequate for a stock-ish Type IV. Figure 120-150hp for the bike engine.