mud clutch

[kfx450]

what are your oppinions.

last muddy race we burnt up a new ztr1000 spring with 3.5g rollers and a 780 belt. stock motor and maxxis razr cross tires. 2009 drr50

we now have a stage6 cylinder kit. drr90 pipe, reverse intake, 21mm pwk carb. 782 belt, 3.5gram rollers, white koso spring. maxxis razr cross tires.

I know the recomended set up for this cylinder is a 1000ztr with 3.75gram rollers. this was the spring I had on hand so I stayed with the 3.5grams. I also have a new stage6 soft and medium spring in stock with a 3g-4.5g roller set.

I was told last time to set up for finishing the race strong. well I am not sure what that means. should I run smaller tires less stress on the cvt. or maybe run a 1500 spring with 4g rollers.

thank you
jayme

[Hetrick Racing]

The answer would be easier to give if you knew what rpm with that pipe the engine makes the most hp and torque.You stated the ztr 1000 and 3.75 were recommended so the engine must have a good mid range power curve,with this pipe?If your spring is the only issue i have to ask.
Does it seem to have a high rpm power curve ? if so what I would do is step the spring up to maybe a Red Malossi and drop to 3.0 rollers what this should do is allow the engine to come into the power quicker and not loose a bunch on the dry parts of the track. The 1500 /4.0 set up may do the same thing but I have (depending on the pipe) lost belt travel with this set up on a 70.One other thing possibly a 787 belt would help because it would start out higher on the rear pulley giving you a bit more bottom end. Of course going to the smaller tire will help this but then your taking the chance of getting stuck in the ruts.

[skyeryder]

we have similiar motor mod but with SMS pipe we run 3.5 rollers, 1500koso spring and a 787 belt, once we put that cvt set-up on this thing rips, it's pulled numerous holeshots.

My fault are you still a 50cc ours is 70cc

But the 787 belt did help ours when it was a 50 a bunch my .02