1989 yamaha exciter engagement and max RPM question.

[Al]

I am working on a 1989 yamaha exciter, 570 cc with PSI twin pipes, bender fresh air kit and comet clutch. Does anyone know what the max RPM should be and how low the clutch engagment can be? Currently engages at 4600 rpm, max 8100 rpm. Looking to drop engagement to make it a little easier for the young folk to ride. Thx Al axcarlac@gw.dec.state.ny.us

 

[vmaxjohn]

what clutch do you have on there? back then, the hot thing was to throw on a Comet 108...You should keep shift out at what ever the pipes like it, but you should be able to mess the engagement.

Here's what to do:

Figure out what color code your primary spring is now.
Figure out the specs on it, either measuring it, or give PSI a call and see what spring they (hopefully) provided. Doesn't sound like it's a stock spring for sure, stock comes in around 3700!


From there, you can hopefully choose a spring that has a softer initial force, with teh same shift rate. This will lower the engagement, but keep the top end rpm close to the same.

Can you post what spring you have, and where it came from?

 

[Brad]

exciter

max rpm 7250 makes no more power after that

 

[vtsrx]

spin at 8000 and the piston skirts blow apart from experance 7300 is max

 

[Al]

exciter engagement and max rpm

The clutch is a comet 108 the spring is red with a white strip, with J-1 weights . I think these are polaris parts although I cannot verify because of the age. At 2 3/8 inches and 1 1/8 inches the tension in pounds is 102 and 222 respectively. I e-mailed psi about engagement and max rpm with no response. It appears that the aftermarket parts industry changes and is in touch with the late models only. I am thinking about using a silver/ black comet spring with tension of 85/203 at the above dimensions. A chart I found seemed to reflect that my engagement rpm will drop from 4600 to 3800 with this silver/black spring not sure about the max rpm.

 

[vmaxjohn]

That spring change could be close, maybe not enough for hit your top rpm goal.

Honestly, I'd call Olav Aaen, he's got more numbers in his head than a NASA computer. He gave me a set up for my old exciter off the top of his head, and it worked just as he said it would. I think Aaen's website is on TY links, or you can do a search. Good luck!