I just picked up an old 88 Formula MX which has a Polaris open face primary with a blue spring. I want to lower my engagement from 5000 to maybe 3500 or so for the kids to ride this easier through trails.

If I keep the shift tension equal and try to reduce the engagement tesnsion, will this accomplish what I intend or should I be looking at new weights. I dont see any notching or flats on the flyweights at first glance but I will be taking a closer look this weekend, and also verifying if it is even shifting flat to begin with. I didn't want to put a lot of science into this as its just a kids trail machine.

Thanks for any advice before I get too deep.....
Scott

I'd do the same thing, about 100 start tension.

Do you have to do anything with the weights in the clutch if you change the spring?

Do you have to do anything with the weights in the clutch if you change the spring?[/b]


No. Not if you are just lowering the engagement. Like hillpounder said just find a spring with a lower starting tension and the same end tension and you should be good.