I thought you were running with F7s, there is no modern 2 stroke cat that should be engaging at 3100, twins should start in around 3600 to 3800. yours is way too low and could easily cause the dreaded cat bog. check you clutches something is wrong. Who has been choosing you clutch parts for you a 60 degree front angle on a little 600 seems a bit steep what other choices have you made???????
dude, this is an old post now. about a week old. My spring has already been purchased and installed. It shows that nobody in here knew anyway. And yes a 60 degree start angle is fine. You should try one and see the difference from just a stock...what 55 or even 53 angle will do. I have another spring now and i've been using it for about 5 days now and i'm engaging at 4600.