I recently bought a messed up 1971 Rupp black widow. Unfortunately it was painted and did not have the original motor (or original Dellorto carb.) I guess that's understandable as the bike shipped with no governor and no air filter. So i can't imagine those engines lasted that long.
This particular Black Widow had a snow blower 5hp motor. The carb was a messed, and not angled either. So i installed an angled intake manifold and a standard tecumseh/china $10 carb on the bike. It rode and ran really well. The guy put a nice motor on this bike, it was responsive and fast.
For fun i searched for an original Dell'orto ua19s carb. Someone here was selling one for a decent price, so i bought it. Then off the blackwidowmotorsport.com and got the required throttle cable ($50!!) and the intake manifold ($40). Got it all installed and ran the bike. There is definitely an improvement. Not like night and day, but a lot more RPM potential and more responsiveness from the Tecumseh. It is an improvement, but for the price, frankly it's probably not worth it.
It got me thinking... instead of spending all that money, was there another way to get the same results? Now mind you, i can't match the look of the euro Dellorto, but perhaps there's a way to get that slide carb performance, without spending hundreds of dollars.
This particular Black Widow had a snow blower 5hp motor. The carb was a messed, and not angled either. So i installed an angled intake manifold and a standard tecumseh/china $10 carb on the bike. It rode and ran really well. The guy put a nice motor on this bike, it was responsive and fast.
For fun i searched for an original Dell'orto ua19s carb. Someone here was selling one for a decent price, so i bought it. Then off the blackwidowmotorsport.com and got the required throttle cable ($50!!) and the intake manifold ($40). Got it all installed and ran the bike. There is definitely an improvement. Not like night and day, but a lot more RPM potential and more responsiveness from the Tecumseh. It is an improvement, but for the price, frankly it's probably not worth it.
It got me thinking... instead of spending all that money, was there another way to get the same results? Now mind you, i can't match the look of the euro Dellorto, but perhaps there's a way to get that slide carb performance, without spending hundreds of dollars.
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