Build me a CVT

[BEEFKING69]

Im looking to rebuild my crossfire cvt from the ground up...heres the tricky part....i ride all types of terrain...dirt,mud,sand,hard pack,hills,bigger hills,creeks,swamps,fire roads,rocks...So atm heres the list of mods done to the crossfire so far.

Crossfire 150
Uni filter
Some sota ebay glasspack style muffler off a buggy at the junkyard
60mm jug with HC piston
Big port head with SS valves and titanium springs
A-12 cam
12g slider
yellow clutch springs
yellow contra
custom oil cooler
Mythical factory 26mm cv carb

Top Speed 45mph

With my setup now its got decent low end and decent top end....but it keeps burning clutches up (yellow springs?) and its leaving something to be desired in the low end and i dont wanna lose my current top speed cause i drive it to town to get smokes and stuff and makeing the same 10 mile trip in the HH Twister at 32 is rough :/

So is there any way to get better low end and still keep my current top end?

Also im interested in a stroker kit sometime in the future +6 or +8....pros cons any specific kit i should get?

[xlint89]

To me, it sounds like you have a good combo already. My top speed is about 40 MPH, so if you're getting 45, that's pretty good. I would have to guess your internal gearing is a little different than mine. (Yerfs are geared for good bottom end)

Not sure why you're burning up clutches? What size rear tires are you using?

One of the best mods you can do (and is FREE) is to optimize the air flow into the CVT. This will help keep temps down and might help some with your clutches.

Clean up the air openings (often there is casting slag that can be removed)

Eliminate the stock intake snorkel and install a scour pad (make shift filter) over the case opening to allow more (filtered) air in


The only other suggestion I might make would be a performance secondary pulley. They have optional "race" and "rec" grooves in them. Who knows, maybe the "race" set up might keep you in low range a little bit longer, but should still allow you to hit top speed over extended runs?

I have the KNM "perfromance pulley" and didn't notice any top speed gains as advertised. But I did notice a little more bottom end performance. I don't remember if it had the optional "race" groove or not though....

Just something to think about

[BEEFKING69]

Stock tires and ive already took the cvt boot off. and yeah thats what i was wondering if the oversize pulleys are worth getting. i also wanna try a dr2 variator. Also i think my motor is actually a hammerhead motor with a howit cvt cover si i have the hammer head finals plus the stock crossfire sprocket.

[SYCARMS]

The performance variator will make a difference since the pulleys are larger but the type of ramping is what is most important and different performance manufacturers use different ramping. Many are designed for scooters which will react differently than on ATV's or mostly buggies. Now there just is no magic bullet when it comes to tuning a cvt. You will tune it differently for steep hills, sand or mud as compared to normal trail riding. The only thing that will push you past that problem is if the motor has some extreme power. Keep in mind that these engines were designed originally for the much lighter scooter. The 6mm or 8mm stroke kit will greatly improve the over all performance but you will want to go with a long rod stroke kit which will come with a longer cylinder requiring no spacers. The short rod uses the normal cylinder height which allows the piston to travel extremely low in the cylinder sleeve (weakest part of sleeve). Now for the clutch burning out, if put under a huge load it will slip and heat up and eventually burn up. The only way to remedy this is to build more power into the engine with a better clutch. Prior to my recent build I ran 12gr. rollers. I now run the stock torque spring, and 16gr. rollers with no stress on the cvt.

[BEEFKING69]

Any particular brand you recommend for the stroker kit and pulleys? My clutch problem seems to crop up when i do a lot of slow riding.....like its not engaging fully