graham2
06-22-2006, 01:15 PM
(Yahoo group looks over - reposted)
I've a stock derestricted 2001 Vino (50) with just a Leo Vinci Sprinter pipe that is probably obsoleted now. This 'street pipe' gives what I think is a small increase in acceleration and top RPMs, and about 3-4 mph increased top speed. (Shaped like a smaller cone-reverse cone expansion chamber, sounds like one as well, just not nearly as loud.) I decided a while ago not change to a 'real pipe' that would require tuning rollers and springs, as I thought I might just leave that complex job to Yamaha given their experience and superior resources (compared to mine) ;).
I noticed that I got better acceleration if I stayed off WOT and crept up slowly. I was getting top speed around 42, put not going full throttle except
rarely, and the last 5 mph or so was pretty slow in developing.
Last week I rejetted to the JOG #78 (from stock #64), together with the JOG pilot jet (downsized), but the OEM JOG needle I obtained would not fit in the vino needle jet. The Zuma needle does indeed fit, but that needle stalls my stock 50 instantly with this pipe with any throttle other than idle. I put the Vino needle back in, by the way it tapers far more than either the thicker JOG needle or comparable Zuma needle, and set it one notch lower/leaner (raised the clip) for the #78 main.
Now it pulls directly to ~43 mph on the speedo (stock front tire, 100/80 Pirelli back, Motorio rear spring for clearance) directly without any delay, and can now do it for the first time even with a good headwind.
I don't have any low end drop out that so often reported with the true expansion chamber pipes, but only get about 3 mph extra on the top compared to maybe twice that. Finally, why do you think the Zuma and JOG use a bit smaller Pilot jet than the Vino on the 14mm carb? -G
I've a stock derestricted 2001 Vino (50) with just a Leo Vinci Sprinter pipe that is probably obsoleted now. This 'street pipe' gives what I think is a small increase in acceleration and top RPMs, and about 3-4 mph increased top speed. (Shaped like a smaller cone-reverse cone expansion chamber, sounds like one as well, just not nearly as loud.) I decided a while ago not change to a 'real pipe' that would require tuning rollers and springs, as I thought I might just leave that complex job to Yamaha given their experience and superior resources (compared to mine) ;).
I noticed that I got better acceleration if I stayed off WOT and crept up slowly. I was getting top speed around 42, put not going full throttle except
rarely, and the last 5 mph or so was pretty slow in developing.
Last week I rejetted to the JOG #78 (from stock #64), together with the JOG pilot jet (downsized), but the OEM JOG needle I obtained would not fit in the vino needle jet. The Zuma needle does indeed fit, but that needle stalls my stock 50 instantly with this pipe with any throttle other than idle. I put the Vino needle back in, by the way it tapers far more than either the thicker JOG needle or comparable Zuma needle, and set it one notch lower/leaner (raised the clip) for the #78 main.
Now it pulls directly to ~43 mph on the speedo (stock front tire, 100/80 Pirelli back, Motorio rear spring for clearance) directly without any delay, and can now do it for the first time even with a good headwind.
I don't have any low end drop out that so often reported with the true expansion chamber pipes, but only get about 3 mph extra on the top compared to maybe twice that. Finally, why do you think the Zuma and JOG use a bit smaller Pilot jet than the Vino on the 14mm carb? -G