My first Rupp

[jacobsonp]

Thanks William W. for the helpful info that led me here! My first minibike experience was my new 1964 Taco 22. Right now I am anxiously awaiting delivery of a Rupp Roadster 2 that I recently purchased. My motorcycling experience includes some success in pro mx during the early 1970s, AMA off-road, dirt track, and AFM roadrace. Currently my only bikes are a 2000 Specialized FSR XC Comp and a 1997 Yamaha YZ 125 (approx.) tuned by Rick Peterson Motorsports. Another one of my hobbies is my completely restored 1973 BMW 2002 comp./show car. I have extensive fabrication and computer design experience,and discovered Rupp minibikes while doing some design research for a minibike I want to build from the ground up. I look forward to any reply regarding a common interest (broad). One of my first Ideas regarding the Roadster was replacement of the diaphragm carburator with the Delorto that was original equiptment on the Black Widow. However, my primary concern is optimum performance, and I would appreciate some other opinions comparing the performance and practicality of this modification given the cost involved.Thanks and remember, rubber side down, shiny side up, Phil

[Blackwidow]

Phil, the performance of a Dellorto is unbelievable for 2 reasons. 1st ...it is a VERY precise carb that has excellent fuel mixture capabilities which always make better power/torque than a poor mixing carb. 2nd.... performance is increased due to the lack of a govenor.

For best performance you need to use the Blackwidow exhaust pipe as well due to the muffler in the Roadster2 pipe hampering performance.

Now for the bad news......if engine is worn (which most are) a Dellorto and no govenor will definitely ends its life very quick. The rods are prone to breakage due to excessive rod brg clearance from a worn rod journal on crank. 95%+ of all Rupp motors I have restored have had cranks from .004"-.031" wear on rod journal...and those engines all ran.