08 MTX "Loud primary clutch"!!!

[Nytromayhem]

This is my first yamaha sled! I was wondering if all yamaha primary clutchs are loud? It has a clunking sound, it sounds like its ready to fall apart! I took the clutch apart and every thing looks to be in good shape! Im just wondering if this is normal or is there something to look out for!


Thanks!

 

[Amped]

Yea this is normal

 

[0007]

Ya they rattle
It's not a clutch problem it just the power pulse of the engine at idle, it's "Lumpy"

 

[MTdream]

rumor has it, there are a couple fixes...one is some rubber o rings on the primary bolts..another is a .020 shim behind the spider...

 

[Frostbite]

Bump your idle up a hair and it will go away. I can't remember exactly but, I think mine is in the vicinity if 1,650 RPM.

Frosty

 

[neversummerwyo]

I believe it is the bolts that hold your weights on... Normal occurance from what I hear. Someone chime in if I am way off base here...

 

[4bangrboost]

every nytro i have rode has done it. maby yamaha will listen some day and fix that kinda stuff?

 

[shortstop20]

This has been a complaint ever since the 4 strokes came out, mostly on the 3 cylinder models. The 2 stroke triples had the same clutch and nobody ever complained about it. The quieter motor is the only reason you even hear it.

 

[Nytromayhem]

Thanks for all the replys! Too know that the noise is normal easies my mind! Other than a noisey clutch, Im very happy with this sled and the qauility of yamaha!!

 

[MTdream]

I believe it is the bolts that hold your weights on... Normal occurance from what I hear. Someone chime in if I am way off base here...

yes, this is what I was referncing above...AmBush and I are working on a solution (we were told about) and will post results in a day or so...

 

[KFD070]

Glad to hear this is normal as I was wondering about that noise myself.

 

[WFO or go home]

Mine sonds like rattling sheet metal until you get up to the 6000 RPM range.

 

[MTdream]

yeah our little washer fix on the arm bolts did nto yeld much value, so going to go the path of putting a .020 shim behind the spider, have heard rumor that this will significantly minimize the noise...

 

[WFO or go home]

I am going to turn up the volume on my MP3. I will keep everyone posted on the results.

 

[rotax]

interesting.. i notice it a bit more on other, quieter nytros. but don't notice it too much on my own.

mine does idle higher..17-1900 +\-..and has a louder exhaust..

i know there are plenty of doo guys with this as well.
even after balancing, and new parts...

increase idle to ~2k and sounds fine..< 1700 and it becomes noticable.. weird stuffs.

 

[MTN_VIPER]

This type of noise can be caused by weight rattle. Bumping up the idle speed, increases centri***al force of the weight which holds it against the roller. Instead of allowing the weight to swing back and forth between the roller and moveable sheave at low idle speeds.
Most Yamaha weights have a little bit of swing room between the roller and moveable sheave. Yamaha moveable sheaves bottom/stop against the spider. Some other brands of primarys bottom/stop against the weight, with no swing room.
By having the sheave stop against the spider, and having the swing room. Yamaha can use different sized rollers, without it effecting the moveable sheave to belt clearance.
Some factors that can effect weight clatter would be idle speed, number of cylinders (power pulses), weight profile mass, and roller size.
Weight clatter dosn't usaully cause any durability issues.
For those of us who have been around awhile. May remember the old Cat hex drive primarys, they were really loud with spider/weight rattle!

 

[MotoPsycho]

I am going to turn up the volume on my MP3. I will keep everyone posted on the results.

That's what I did... fixed the problem 100%!!!