ANYBODY DONE THIS?

[bikeseamus]

 I was reading where a guy put a set of downdraft weber carbs on his vision and kicked some serious butt with it on the racetrack, with other mods ended up with 78 horses. Weber and Dellorto both make a two barrel downdraft 36mm carb, and they are both pretty cheap, around 125.00. Anybody done this? How about interchanging bigger pistons? Like many of us visionaries, I have a spare engine, and would love to make a streetable sleeper. good for embarrassing your friends on modified harleys. Just kidding, I would NEVER engage in a SPEED contest officer............. HONEST!

[Blake]

I've been highly concidering a carb change but hadn't thought about the weber or delorto.  I was really thinking about a side draft mikuni round slide (36 or 38mm) but then i was wondering about the extra space between the card and the intake manifold (would be right next to the manifold, just witha  90 degree pipe between the two).  I was also looking into the downdraft keihn race carbs they put on the modernday superbikes, but they dont come individually and a set for a 4cyl bike is around 700 bucks.  a little too much for me.  But if its possible to get a downdraft carb as cheap as you say (which would be as much as i would have paid for a mikuni), i might have to look into that.  i think that would be a more feasable thing to do.


Blake

[RobTx]

Have a part # or a url?  Smallest Weber 2bbl I can find is 38mm and goes for $260.  They have single bbl 34's though.  A set on ebay for $50  right now.  I still have to look for Del'orto.
Rob

[bikeseamus]

 Rob  Enter "downdraft carbs" on ebay, and there are six or eight sets of 36mm carbs there. I guess Porsches and VWs use them quite a bit. I had a Datsun 510 once I put a set on too, with some delightful results. Back in the sixties, if you ran Weber carbs on your drag car, they immediately put you in the fuel injected class. Webers are infinitely tunable, too. They can do anything, and without a laptop and five grand worth of soft and hardware. I'll check on the Yamaha shop in Dyersburg, Tennessee that built the bike, and let you know. Maybe everyone will end up with cheap 2003 carbs. as an old friend of mine used to say.... "we'll see."

[Rick G]

I got a phone number from Jeff Swann,  a couple of years ago , for a guy in the midwest , who raced Visions. He had replaced the cylinder liner and over bored it quite a ways. he also had 3 cranks forged , for a longer stroke. They ended up with 750cc and 93 hp.  He told me that it could be bored close to 600 cc whith the existing liner. look in the Wisco  piston catalog, with the piston dimensions of a Vision and see what might work!  I emailed The fellow in the Gallery who has the Vision race bike (I forget his name) he emailed me back  that is was all bore no stroke  and they were  K& D pistons (I'm not sur of the D, it was Kand somthing.