QT50 HPI CDI Mini Rotor

Who's running one? Interested to hear about all of it.... spill those beans Yo!

Re: QT50 HPI CDI Mini Rotor

Seems a little silly to put a 300 dollar ignition on a moped that you can't even change the gearing on

Re: QT50 HPI CDI Mini Rotor

lol you don't know anything about qt50s.... Not as many gearing options based upon shaft drive but you can totes re-gear buddy. and everything mopeds is silly, you know this.

Re: QT50 HPI CDI Mini Rotor

The only gearing upgrade I know of for a qt50 is PW gears, and that isn't a very big change from what I understand.

I used to own a QT50, it was the first moped I ever messed with.

Re: QT50 HPI CDI Mini Rotor

Buy a qt50 hpi and then report back.

Re: QT50 HPI CDI Mini Rotor

I have the HPI mini rotor, what do you want to know? Fitting was pretty straight forward, it gives you easily adjustable timing and that's about it. With my pretty modded QT it didn't really make a huge difference in performance, i just like the more powerful lighting coil for my 12V conversion and the fact it isn't 40 years old means i can rely on it a little more.

Re: QT50 HPI CDI Mini Rotor

Would you buy it again and did you notice any more low end torque/ off the line pull??

Re: QT50 HPI CDI Mini Rotor

Yes i would buy it again, no i didnt notice any performance gain but your results may vary. For me it was about the reliability more than anything.

Re: QT50 HPI CDI Mini Rotor

Jack Rutherford /

Damn no performance increased noted! What else did you have going on your qt in terms of performance upgrades?

Speaking of gearing, I ran across this. I should call and see if it is the same as the qt50 main drive gear or slightly different. pwonly.com > hi performance parts for pw50

"Yamaha PW50 special transmission gear designed to give PW50s more low end torque. Works awesome for starts & holeshots.

Replace the standard OEM gear with this special heavy duty, USA-made Top End Machine brand transmission gear. Uses the same gear ratio as the QT50 transmissions, but this gear is located inside the clutch cover making it easier to change than the older rear end QT50 gears. CNC Machined from Billet. *Since this is a bolt on part, you can always go back to stock if you want to.'

This must be a bigger main drive than is stock on PW50 so not sure how it compares to what is on the qt but may not be helpful. (edited)

Re: QT50 HPI CDI Mini Rotor

Everything pretty much, MLM pipe, VM18 carb/intake, 70cc kit, boyesen reeds. Will see how it goes in a few weeks as ive now ported the case, put in stiffer clutch springs, replaced the crank bearings, all seals and put in a stuffed crank but i wont compare it to the stock ignition again. Not sure about the gear but for $50 it might be worth someone trying.

Re: QT50 HPI CDI Mini Rotor

I have a very similar setup hence my asking about the cdi... really would like more info and maybe another opinion, but to think I'm going to scoop and install this winter.

Re: QT50 HPI CDI Mini Rotor

Jack Rutherford /

There has got to be performance gains. I'm about to find out! Damn it!

Re: QT50 HPI CDI Mini Rotor

Jack Rutherford /

Main benefit of this system on the qt is running a CDI with a curve and keeping temps under control. I need to do some more extended riding but my initial thought was that I could almost run without a temp gauge with the HPI system. Once you have it dialed in, life is cool.

You might see a slight bump on top end and a bit more acceleration early on in the rpm range. 12v is nice as well. Too bad you can't get it at Derbi/tomos/puch prices.

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