drew24
New member
Okay, I know there are millions of threads out there on clutching but I have read for hours in the last few days and am still confused a little. I want to play with and learn clutching. So anyway, I have a 99 srx 700 and the clutch is all stock. I just bought the 8dn-20 weights off of another member today. What helix and springs would be a good starting point? I ride trails most of the time but I would still like some top end performance. And also how much does changing clutching affect fuel mileage? I am eager to understand this stuff a little better. I appreciate any info.
helix close to 51-45 should work perfect or close to it .....u will need new roller 99 is the only year that srx put 15mm
drew24
New member
Thanks for the input modsrx. What roller do I need and where is the best place to get it?
15.6mm u can try to post in the wanted section or direct at dealer ...
drew24
New member
Thanks a bunch. I never saw anything about that before. I really appreciate it.
nothing wrong with 15mm rollers, you DONT need to change those, you just need to use the right clutching parts is all.
you can use either the stock 8dn10 weights or the 2000-02 srx 8dn20 weights. With a 98-99 srx youll need slightly more front primary spring pressure because they dont make as much hp as does the 2000-02, so use a stock yellow/white/yellow(45/128kg), with the 8dn20 if you already bought them, 4.5 rivets in both holes. On the back clutch use a 52/44 helix or close with a green dot sec spring and it will run pretty good all around.
you can use either the stock 8dn10 weights or the 2000-02 srx 8dn20 weights. With a 98-99 srx youll need slightly more front primary spring pressure because they dont make as much hp as does the 2000-02, so use a stock yellow/white/yellow(45/128kg), with the 8dn20 if you already bought them, 4.5 rivets in both holes. On the back clutch use a 52/44 helix or close with a green dot sec spring and it will run pretty good all around.
drew24
New member
Thanks for all the input. I have one more question. What would be the fastest way to get the rivets? I should have all my other parts in a few days and would like to get it put together as soon as I can. Snow is going to be melting and I might have a chance to go north this next weekend. Thanks
drew24
New member
Ok guys. I finally got to test my clutching. I am running the 8dn-20 weights with 4.5 rivets in both holes. Brand new stock y-w-y primary spring. Pioneer 51/45 helix with green spring at 70. I ran about 8100 rpms at WOT. How do I get that up? And when I am on it for a little while the rpms drop between 7700 and 7800. Probably at 80 mph. Is that normal? Thanks.
your gonna need to lighten the tip of the rivet a little bit go to 4 grams in the tip and retest. You can either just grind some off the fat side of the head or drill a small hole thru it. you keep track how much you remove via a gram scale. With the helix being aggressive at 45 finish youll need to lighten up the tip a bit on the 98-99 srx. this is the cheapest way to dial it in without buying a differnt primary spring with more force to raise up the rpm a tad.
youll want just a tad more then 8300(8350)rpm for that sled
drew24
New member
Thanks mrviper. I don't know if I can retest this year yet. I hope so but the forecast doesn't look good. I plan on doing the topend this summer so would I be better off waiting until that's done to fine tune. The sled has 4500 miles on it.
drew24
New member
Carbs,Powervalves, and clutches have all been cleaned recently although I haven't checked the powervalves in a couple hundred miles. Thanks for the input. I will be going through all that again this summer.
YAMMIEGOD3:16
Active member
your on right track for good clutch set-up. i will answer fuel mileage question because that was left out. it will be bad if ya get clutching right because you can,t stay off the throttle. lol. 3:16 (yammie tony)
drew24
New member
That's a pretty awesome answer. I can only hope that's the case. Just wish we had more snow.
Mrviper, If you have a 2001 motor and bdn-20's what primary spring would you run or do I leave the rivets off? I have a 51/45 Helix and a Green Secondary spring?
what brand is the helix? and do you know the helix is a 51/45 or is it a coded helix that someone told you its a 51/45.
I ask because most of the time the coded helix are not the angles you think and this is what messes up the set ups,low rpm and such.
Hi MrVider, it is a stock 48/42 Yamaha Helix not sure what sled its from but when my friend measured the angles it was 51/45 he played with it a lot with his different clutch set ups before he gave it to me... Also I just checked my weights and I have BDN-10 weights not the 20's but will look for a set.