bbk/rollers/cdi upgrade

[jdadesignstudio]

Ive installed enviromotos 72cc bbk on my 139qmb. I held off on installing the 8g rollers it came with, I first installed the bbk, the uni air filter, and the #90 main jet. I was pretty happy with the result with just leaving the stock rollers in, but I decided to try putting the 8g in. I also ordered the "blue racing cdi" from scrappydog scooters.

Here are my results:

1.) stock rollers with stock cdi-best overall acceleration.
2.) stock rollers with blue cdi-better acceleration 0-15, lag from 15-30, then it picked up a little.
3.) 8g rollers with stock cdi-laggy from 0-20ish.
4.) 8g rollers with blue cdi-maybe a bit better than option 3, but not by much.

Top speed was the same with all 4 options.

So my question is, should I try lighter rollers, or another option? Or should I just stick with stock rollers and stock cdi since thats giving me the best performance overall? (just kinda seems a shame to have spent money on new rollers and cdi, and tools to get the variator off, just to have them sit in the garage...).

Thanks,
jon

[90GTVert]

I'd stick with option 1. The money spent on tools is never a waste IMO. CDIs are almost always a poor way to spend money unless the stocker has a low rev limiter (I've heard some are limited at 10,000RPM... which will never affect most GY6s).

[jdadesignstudio]

Ok thanks, I agree about the tools for the most part. I originally bought the ztr variator lock tool, and thats the only tool I feel was a waste-it bolts onto the existing bolt holes, but unless Im missing something, you cant use the existing bolts because they are too long (since they are meant to hold the cvt cover on), so the tool doesnt stay in place unless you have shorter bolts of the same size and thread. I wound up just having to buy an impact wrench, which Im sure I will use again. I was a little surprised the 8g rollers decreased performance-the rest of the bbk from enviromoto seemed to work together so well...

[lshigham]

Jul 16, 2011 14:39:35 GMT -5 90GTVert said:

I'd stick with option 1. The money spent on tools is never a waste IMO. CDIs are almost always a poor way to spend money unless the stocker has a low rev limiter (I've heard some are limited at 10,000RPM... which will never affect most GY6s).

I had one limited to 5500rpm, but I've never heard of anyone else having one that low.

[90GTVert]

You can pick up shorter bolts for less than $1 at most hardware stores. They're M6. The tool is nice to carry under your seat, along with other necessary tools and a belt, in case you ever break a belt on the road. Jeremy seems to really like the heavy rollers anytime I see him giving advice. I usually end up on the lighter side. Unless you are going for max performance for a certain purpose, it's personal preference to some degree.

[Fox]

Try some 5 gram rollers. The thing will accelerate much faster and it'll walk up fairly steep inclines at 25-30 mph. Won't increase top end but you'll reach top speed quicker.

[kymcotallinn]

Hi, I have been playing with rolls and all the other parts, starting from 8,5g. rolls and stock settings.

Best solution I got for my 4stroke engine:
5gramm slider rolls.
Unrestricted CDI (+10km/h)
Iridium spark plug.
Original/stock torque spring.
Malossi Yellow clutch springs.

Maybe you can try this also ?

[jdadesignstudio]

Thanks guys, ill try some of this out. Does anyone have experience with the polygon shaped rollers-are they worth it? or should I just get round ones?

[90GTVert]

I love sliders. They hold up much longer than rollers from my experience. Sometimes you get a little more top end and acceleration.

[jdadesignstudio]

Sounds good, thanks! I think Ill get these set of rollers to experiment with:
www.provoscooter.com/scooters/gy6/ruima-variator-roller-tuning-kit-16x13mm.html
and then get the appropiate sliders.