Primary clutch red hot!

YAMAHIZAL700

YAMAHIZAL700

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Joined
Feb 12, 2005
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Location
durham, ME
Tonight I was just trying to load my sled for a nice 2 day trip and it seems to be overreving and my primary is so hot that if spit on the clutch it sizzle right up. I recently changed track but have ridden her a few times without problems.(Around the yard very little). Its perfect timing since I am supposed to leave tommorro morning. ANy Ideas anyone?
 
Im not sure whats going on here. How do you know when clutch is worn out? Seems to engage at 4300 rpm but when i give it gas it wants to burn the belt and does not move right. I tried a different belt still the same. I can easily turn secondary with track so I know nothing is binding there. The wierd thing is the last few times i have gone around the yard the trottle had been so responsive and the sled wanted to go. Now when i get on to her she bogs and wont move much. Im now def. not going to presque Isle tomm. so this really blows. Hopefully its no big deal but if anyone can help Id reall appr. it. Im really bummed out and stumpped on this one.
 
How much driven clutch pressure do you have? If the driven clutch is way too soft, it will shift up with very little power, causing a huge bog. I would start by pulling the driven clutch and checking for 60 or 70 degrees of preload. If the settings are OK try to rotate the inner half of the clutch while holding the outer startionary. It should take considerable force to cause the inner half to move, like 12 - 15 lbs of force. So, verify the clutch settings first. Did you have the primary clutch off the engine recently?
 
Nope havent had the primary off but everything looked to be ok a first look. Do you think that It could just need some lube. I havnt done it for a while and have a can of that expensive comet clutch stuff. Thanks guys, Im gonna go check it out again today with i good nights rest under my belt to hopfully see whats happening.
 
YAMAHIZAL700 said:
Nope havent had the primary off but everything looked to be ok a first look. Do you think that It could just need some lube. I havnt done it for a while and have a can of that expensive comet clutch stuff. Thanks guys, Im gonna go check it out again today with i good nights rest under my belt to hopfully see whats happening.
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So, assuming the clutch isn't hot from transmitted engine overheating or failed PTO crank bearing, it has to be friction, right? From the belt, most likely? So it ought to be a problem with the primary clutch, or something frozen in the drive train.

I'd pull the belt, and make sure the secondary rotates the track easily with the track off the ground. Then I'd pull the cover on the primary and look at the spring, make sure the sheave slides easily, make sure the weights are free.

I would think that kind of belt friction heat would be most likely due to a broken primary spring, so that even at idle, the sheave are squeezing the belt.
 
Is the belt riding real low in the secondary? It should be up flush or just above the sheaves.
 
maxdlx said:
I'd second the primary spring being broke or bagged. Maxdlx
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Yeh, it oughta take about 5 minutes to pull the primary clutch cover and look at the spring, check the weights and rollers. Unbolt the six cover bolts, the spring (or two parts of the broken spring, if that's it) will slide right off.
 
I saw a 99 sx 700 at a sale that had the exact same symptoms. The primary spring was broke out near the end, and the clutch was scortching hot. Maxdlx
 
broken primary spring

Mine did the same thing last spring. Everything looked fine. Popped off the primary cover and the spring came out in 2 pieces. Replaced the spring and all was well again.
 
I just finished clutching ( new rivets and WWW spring in primary, backed off preload on red secondary to 80) and replacing my track.
took the whole week that i had off.
well on new years eve it was complete, I fired it up, everything was good to go, and i decided to load on the trailer and be ready for when/if ever we get show again in michigan

well, i had a hard time loading onto the trailer, and smoked the belt some, I was hoping it was just the dry wood trailer bed and ramp, but now i am a little worried I may have something not right too?

either we both had dry trailer syndrome, or we both may have some clutch issues. I want to test this clutchign out before heading north with the buddies I'm trying to beat, only problem is north is the only place the snow is and I may have no test and tune time........ :o|

Ramb
 
Hey Ramb, when you finished the assembly, did you run it with the belt guard off and the tail suspended? Did you verify that the clutches were shifting all the way out and back? Using this test method, you can verify that the clutches are responding to power input and you can simulate track load by applying a lttle brake. With the engine running and clutches shifted about 50% or more, squeeze a lttle brake. If all is well, the clutches should immediately bach shift. Applying more power will cause the clutches to upshift. If it passes this test in a nice smooth almost effortless way, I would not hesitate to head for the snow.
 
ModMMax said:
Hey Ramb, when you finished the assembly, did you run it with the belt guard off and the tail suspended? Did you verify that the clutches were shifting all the way out and back? Using this test method, you can verify that the clutches are responding to power input and you can simulate track load by applying a lttle brake. With the engine running and clutches shifted about 50% or more, squeeze a lttle brake. If all is well, the clutches should immediately bach shift. Applying more power will cause the clutches to upshift. If it passes this test in a nice smooth almost effortless way, I would not hesitate to head for the snow.
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Great tip! A very important point for anyone after doing any transmission work - can save a lot ugly surprises after trailering a just-reclutchedsled a couple of hundred miles.
 
good idea, I was thinking of jacking it up while on the trailer and run it again, I did run it in the polebarn to dial in track tension and alignment, but did not look at the clutch shifting. I'll do i this time


one other questions, (now that I hogged YAMAHIZAL700's thread :rolleyes: )
what do you clean the clutch sheaves with, as i expect some black marks from smoking that belt a little....
someone said 100 grip sand paper, seems too harsh to me....

thanks for the responses

Ramb
 
Clutch Cleaning

I use scotch brite because you don't want to get sand, from the sandpaper in the clutch bushings! I still tie a piece of small rag around the primary shaft, to minimize contamination of the bushing. Solutions you can use... soapy water is good, acetone, and clorinated brake cleaner also will work. The non-clorinated stuff seems not as good. I usually give the tower bushings/helix buttons, a small shot of silcone spray.
Also when you do your clutch check, bring the track up to about 70mph and see if it tight enough. if it's too loose it will flap around allot when you let off the gas.
 
ModMMax said:
I use a scotch scrub pad. Green or red and hot soapy water.
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Steel wool (very fine) and some acetone, followed by a dry cloth. My usual method it to chuck the secondary into a lathe and turn it up to do that. You might be able to guess how I scrub up the primary clutch - but I certainly wouldn't want to promote that as the safest way to do it.
 
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