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View Full Version : soft acceleration - feels wrong


mcollinstn
09-08-2004, 07:22 AM
Okay, this isn't a Vino, but it is a minerelli.

Aprilia SR50 liquid cooled, carbureted.

I just got this booger home - a friend picked it up for me.

It has an Arrow pipe on it, which has definitely made it more "pipey".
Appears that stiffer clutch springs have been used on the clutch (a three pad delta).

I took off on it, and it was a dog off the line (compared against a stock Zuma). Acceleration continued to be pitiful, and any hill of significance dropped speed horribly. The motor, however, continued to spin happily. With my 220 pound butt on it, I was able to find a long downhill in the neighborhood and see 43 on the speedo although it slowed to 28 on the uphill (mild grade, not steep hill).

I took the side cover off and removed the clutch. Clutch was polished and pads were glazed. Sandblasted the clutch and pads, cleaned them. Took side cutter pliers and slightly opened one turn of the springs for less tension. Reassembled. While apart, did notice that the belt is worn some (not a lot, just some) and there is belt dust in it. Previous owner says pipe and clutch changes were done when he bought it, and has never had the side cover off sothe dust is from 2000 miles.

After the cleanup and deglazing of the clutch, I could feel a more positive clutch hookup, but not really any better accel. I assume the rollers could be worn or something but I don't have any experience to be able to diagnose these things with the seat of my pants.

Any ideas?

Bad*Brad
09-08-2004, 12:02 PM
At your weight you will need to be running 3.0 to 4.0 gram roller weights. Just doing that, you should notice a huge difference. And, if there are not any Shims on the torque spring you may want to consider adding some.

One other thing, are you using a performance variator ? or, does the Variator your using have 16x13mm rollers ?

monzav8
09-09-2004, 06:22 PM
Yup, sounds like a transmission tuning issue. You need to try out some lighter rollers. How much did the previous owner weigh? This does make a big difference in the characteristics of the scoot. If he weighs 160lb (or whatever) you can get it to accel and top out like he could with some tuning.

BTW, the SR50 is a good performing scoot. Just sounds like it needs some adjustment to get it back to being a rocket...