srx over-rev

O

ottawaair

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more clutch ??'s. here is what's happening- from idle to wot with fairly good traction - jumps to 85- 8600 rpm & climbs to almost 9000, I get out if it at that point. Here is what is in there right now 1 1/4 X 136" ripsaw, 21/39 gears with 8tooth drivers, primary- YWY, 8DN 20's loaded- weigh 52.5 grams, secondary- stock helix 47 deg, pink spring at 90 deg twist, new 8DN belt. Do I need more weight in the tips ??? any recommendations.
 
what helix do you recommend?? How many grams of weight does it take to change the rpm's, would adding like 2 grams be a noticable change??
 
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Your gearing is multiplying your torque huge. You need a steeper helix plus different primary weights. Your geared for just under 100 mph. You can,t make your weights work properly with your gearing.
 
I changed gears when i went from 9 to 8 tooth drivers. I did the formula i found on here & tried to keep about the same final ratio of about 1.65/1, that is where it was with the 9 tooth drivers. Please give me anidea of what to use for all around trail use & occasional racing my friends.
 
You figured your gear ratio wrong. If Your running 21/39 with 8 tooth it,s like 19/39 with 9 tooth. Anyway...try peening over a 1 gram washer under 4.5 gram weights 7 look for a helix about 53/47. I have a 52/48 Bender that would work well for sale in Canada....$70 shipped.
 
ottawaair said:
I changed gears when i went from 9 to 8 tooth drivers. I did the formula i found on here & tried to keep about the same final ratio of about 1.65/1, that is where it was with the 9 tooth drivers. Please give me anidea of what to use for all around trail use & occasional racing my friends.
Click to expand...

IMO: You are geared too low for a 136"[I run 144" x 1 1/4"]

Your present set up:

for 8 tooth drivers: 21/39 = 1.86 : 1
1.86 X 9 divided by 8 = 2.09 : 1 [final corrected ratio]

My suggestions as a minimum for 8 tooth driver trail type riding[non mountain] :

23/39 = 1.69 : 1
1.69 X 9 divided by 8 = 1.91 : 1[final corrected ratio]

If it was my sled:

I would run a 24/39 that would equate[with 8 tooth drivers] to 1.83 : 1 [final corrected ratio]

JM.02c

ps:
I like Turk's suggestion on a Helix as well. On Yamaha secondaries I have used 53/47 with a Yamaha green spring for an all purpose helix since 1999...drag racing, radar runs + trail riding ect.
 
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You didnt mention if you had more than ample power out of the hole. If so, you could first try loosening your secondary (as suggested by needaSRX) to make your ratio climb faster keeping your RPMS lower. It's easier than fussing with weights and you might wanna try that first and take a couple of passes. Then based on your satisfaction, see if you even wanna fuss with parts swapping.

It's a test and tune thing and if you loosen too much you get belt slip, so keep at it and search this forum for clutch tuning. There are tons of older posts with awesome info.
 
Turk said:
You figured your gear ratio wrong. If Your running 21/39 with 8 tooth it,s like 19/39 with 9 tooth. Anyway...try peening over a 1 gram washer under 4.5 gram weights 7 look for a helix about 53/47. I have a 52/48 Bender that would work well for sale in Canada....$70 shipped.
Click to expand...

Turk, i would be interested in that helix, PM me if you still have it, :)
 
I figured out where i went wrong with my gearing, i was doing the math wrong. I picked up a 23/37 combo to try, will put me at 1.80:1. I also have a 35 tooth gear but not sure if the chain will fit. I was looking for a 24 tooth top gear but could only find them listed for RX-1's. Are they the same gear & will it fit in my SRX chain case??
I already bought the helix from turk.
 
is it a stock yami gear or aftermarket, don't see them listed for any srx's. I think i should be good with my 23/37, puts me at 1.80:1, right about where sideshow says to be.
 
ottawaair said:
I figured out where i went wrong with my gearing, i was doing the math wrong. I picked up a 23/37 combo to try, will put me at 1.80:1. I also have a 35 tooth gear but not sure if the chain will fit. I was looking for a 24 tooth top gear but could only find them listed for RX-1's. Are they the same gear & will it fit in my SRX chain case??
I already bought the helix from turk.
Click to expand...

i think the rx-1's are hyvo and 13 wide chains, like the '00 and newer srx's. your '99 should be a 15 wide chain i think, so i don't believe it'll work.
 
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