doug
New member
Alright guys, although I am selling my 00 SXr 700, I am dying to know what is up with the primary clutch.
It worked great for several years, and then it started to over-rev a little. Then it broke a spring. It broke another spring 300 miles later, and was hitting 9,000 rpm. I took it to my dealer, they completly disassembled it, checked everything. I was with the mechanic, and he paid good attention to all details, checked for cracks, all the basic stuff. Bushing, rollers, etc.. were all fine. He really recommended the Thunder Shift Kit, because you can easily tune it, and he thought my sled could really benifit from a better primary setup. He set it up with what he experienced as a good start for weights, and put a new spring in it.
At first, I was amazed how much better it accelerated. By 200 miles later, it started to over-rev. I kept adding weight, but still over-rev. Finally I said to myself "something is up" and started really looking at it. Both of the previous broken springs broke in the same spot, right at the coil that starts to enter the pocket in the spider. The coils showed rub marks on the O.D., like the spring was not staying centerd, and binding on the edge of the pocket. The I.D. of the spider pocket was galled-up, so I cleaned it up and put a chamfer on it. All was great for 200 miles, then the same shit. Since then, twice a year I have to clean-up the pocket I.D. to keep my revs under control. My WOT rpm's are pretty much OK, but partial load rpms are always too high. Forget about breaking trail with this sled, rpms are through the roof.
Has anyone else seen this, and what is the real fix?
It worked great for several years, and then it started to over-rev a little. Then it broke a spring. It broke another spring 300 miles later, and was hitting 9,000 rpm. I took it to my dealer, they completly disassembled it, checked everything. I was with the mechanic, and he paid good attention to all details, checked for cracks, all the basic stuff. Bushing, rollers, etc.. were all fine. He really recommended the Thunder Shift Kit, because you can easily tune it, and he thought my sled could really benifit from a better primary setup. He set it up with what he experienced as a good start for weights, and put a new spring in it.
At first, I was amazed how much better it accelerated. By 200 miles later, it started to over-rev. I kept adding weight, but still over-rev. Finally I said to myself "something is up" and started really looking at it. Both of the previous broken springs broke in the same spot, right at the coil that starts to enter the pocket in the spider. The coils showed rub marks on the O.D., like the spring was not staying centerd, and binding on the edge of the pocket. The I.D. of the spider pocket was galled-up, so I cleaned it up and put a chamfer on it. All was great for 200 miles, then the same shit. Since then, twice a year I have to clean-up the pocket I.D. to keep my revs under control. My WOT rpm's are pretty much OK, but partial load rpms are always too high. Forget about breaking trail with this sled, rpms are through the roof.
Has anyone else seen this, and what is the real fix?
The rub marks are normal, the galling is not, my 1st instinct would say primary spring coil bind causeing both the overrev as well as the pending breakage, why the coil bind? I would assume that upon dissassembly your dealer checked the moveable sheave bushing along with the cap bushing for excesive play? Process of elimination!
Did you buy the sled new? I know I am grasping at straws here, but Yammi went to the "deep cap" around that time frame on the SX'rs, is it possible you are running a "long" spring with an older "shallow" cap? Your engagement would be high though simulating a high pretension spring.
I am far from an expert, but figured I would toss in my 2 cents
Did you buy the sled new? I know I am grasping at straws here, but Yammi went to the "deep cap" around that time frame on the SX'rs, is it possible you are running a "long" spring with an older "shallow" cap? Your engagement would be high though simulating a high pretension spring.
I am far from an expert, but figured I would toss in my 2 cents
pics would help
Using a short cover style spring in a long cover primary or vice versa might do it. You should have the long cover primary cap on that sled & using the short style spring might give you too much play & cause that spring to explode. When you replace the primary cap you should have to compress that spring to make the cover bolt on.
doug
New member
SX: Yep, all bushings were good. I bought the sled new and had maybe 6,000 miles on it before this started. It now has about 13,000 miles. All bushings still check good. I keep it pretty clean. I agree that the coil is catching on the spider pocket lip and causing the overrev and spring breakage. I haven't broken a spring since putting the chamfer on the pocket edge.
Ding: I'll take some pics if I can, our dig. camera is broke.
Turk: We verified the proper springs, and yes I have to push on the cover to get the bolts started.
Ding: I'll take some pics if I can, our dig. camera is broke.
Turk: We verified the proper springs, and yes I have to push on the cover to get the bolts started.