Just bought a 99 srx 700, my first Yamaha. Very impressed with the quality. Stripped it down exept the motor. Adding extra idlers and speed track with ice picks. Just wondering if I should machine the primary and secondary helix to get it to shift out into overdrive? I plan on porting the engine to 2000 specs next summer. Any tips would be appreciated. Alot of people I know drive bombies and I want some mph and show off my tail light.
yamaholic22
Active member
if you're going to port it next summer might as well go a little more aggressive than 2000 specs, there still is quite a bit more power available there. As for overdrive, you will get mixed results from people because some think that they maintained top end while gaining bottom end by going to the overdrive system, but what many people dont realize is that these sleds are geared from the factory to achieve top end in absolutely PERFECT conditions, which is VERY seldom ever reached, so most of the time you will be able to drop a tooth or even two on some models and not lose any top end. Also, the CVT clutching system is less efficient at overdrive shift ratios because the belt is being wound around such a tight radius in the secondary, robbing horsepower because a lot of the power is being used to bend the belt around the tight radius, creating high shear forces in the belt, resulting in a lot of friction which means power lost to heat.
So I might be better off going from 23/37 to 22 or 21/37 with more pin weight.
99 srx 700
carbon tech reeds
cold air kit
bender transfer rods
stock clutching
99 srx 700
carbon tech reeds
cold air kit
bender transfer rods
stock clutching
yamaholic22
Active member
23/38 is a good gearing selection to go to, even 22/38 or 23/39 is good in most conditions if you really like bottom end and you are getting a lot of traction. On that 98 shoot for 8100-8200 out of the hole, slowly creeping up to 8400-8500 on top end at WOT.