got 2 for you  By  chris5527 (Read 691 times)

These tachs are great and install in five minutes I have one even though my instrument panel has a built in tach.

As far as best gearing MILLSC should be able to help with that he has done many gearing.
Alleyoop

www.trailtech.net/digital-gauges/tto?cat=117

16/50 does a decent job but the hoca sets yield more performance but also cost more I got the biggest gain with the 18/46 set may have got a bigger top speed gain with 17/41 but didn't want to lose hill climbing and torque.

yeah I definitely dont wanna loose torque or hill power just wanna bump on the top end a little.

You need to know what gear ratio you have before you buy gears. Different scooters have different gears. (Models/10"-12"13"wheels). Plus your weight your riding style and area.

Your 139QMJ motors usually come with 15/52 gearing. To get more top end speed you go up on the Counter Shaft Gear 15teeth to 16,18 etc.. and go down on the Final Drive Gear 52teeth to 50,48 etc,,. For a stock motor no matter what size I recommend only go 2 up and 2 down so you do not loose your acceleration.
Alleyoop

All the 10 inch wheel scoots had 15/51 the 12 inch wheels had 14/52 I didn't lose acceleration with the 18 46 upgear as why I maybe should of went all out got the 17/41 set. I still wonder what I could of got with the 17/41 I say with more motor you can go taller on the gear and have suitable torque. I have 15/37 on my 150 and believe I can go to 16/36 and still have good torque with my bigger displacement. I probably won't it runs awesome now so I'll probably leave it. Slider weight costs add up and it runs great now so its if its not broke why fix it type deal.

All depends on the speed limits on the roads you travel on, if they are 25-35 then yea you need some low end torque, but if the speeds limit gets up to 45 you know the traffic is doing 50-55 so you need some top end speed to keep up otherwise your a danger to yourselve and others. If you can't keep up with the traffic speed they will all be trying to get around you because your holding them up and that is when trouble happens. So saying that you need both good low end and good descent top end. I see the 50cc scoots all the time around here wot on the 35 mph streets and the cars are doing 40-45 and the little 50 is holding everyone up. Just like coming up on a guy on a bicycle what happens you slow down and wait for a clear space and go around him putting your car in the other lane and back into the right lane again.
Alleyoop