Help setting up SR 172 Malossi ported!!

[mavio]

Most people use the roller weight they heard was good in a forum. Their scooters will never show its full power because the roller weight depends on a lot of factors. Gearing, belt, variator, counterspring, jetting, rider weight and so on..

I guess your pm pipe is a pm52 and I dont know how much it revs. If it is a more high revving pipe than my pm59 11,5 might be good. 11,5 is probably close to the weight that would suit an mhr pipe and that pipe is screaming.

Try different roller weights untill you have found the best weight.

Good luck!

 

[sr172]

Thats what i was thinking but soo many people have told me different. Yes i am running pm52.

Pm tuning are giving me a rough idea i guess as they wont adivse it to be revving the hell out of it and i weigh 14 stone so i need lighter rollers haha.

Im using a 180 belt standard 125 gearing with malossi secondary gear kit.
i was going to put 12-12.5 gr in.

But i had a gear kit in before and 3 16gr rollers and 3 12.5gr. Raced my firend, changed to standard gear and put all 11.5 gearing in, now it screams not much less than a 70cc and i havent gaind all that much accel considering ive took gear kit out and lightend rollers.

Im guessing maybe my rollers are a tad too light so hopefuly 12.5 will be ok with a gear kit.

pm tuning say my bike will be slower accel an top end with the 125 gearing as im not using all the power, i though 125 would be better accel!

is thats true wat they are sayin?

Thanks

 

[mavio]

The reason a 125 cc has a lower gearing is that it has to little power to pull a higher gearing in the start. Like a car would starting in second gear.

After take off acceleration revs is adjusted with the roller weight and you can make it accelerate at the same revs with std or higher gearing using different weights.

With a too low gearing it will overrev and loose power off the line easier. But I dont know if the std gearing really is too low.

More power in the engine needs heavier rollers too so if you are going to use that pwk its better to start messing with rollers after you have fitted it.

PM definitely know what they are talking about.

 

[sr172]

pm tuning say 25mm dellorto is the best for my bike, but i can get more power from my keihin28mm :S