lund
Pro
My question might not be an issue but i'm concern of probable failure.
It would appear that most clutch noises come from the PTO stub shaft being seperate from the crank and splined to it.
The play between these two components causes enough movement to cause a rattly noise from the clutch at or near idle.
I understand why Yamaha went that rout, as the crank bearings would not hold up to the side load created by the belt clutch drive system.
My biggest question is, how common are the PTO shaft and bearing failures and is there a certain amount of play that is not acceptable.
Coming off a 2stroke and this being my 1st 4stroke, this is new to me. This kinda worries me and would rather replace the shaft if needed then destroy the engine, plus pay for a chopper out.
I run boost and a 174 track so the PTO gets heavily loaded. THX for your reply.
It would appear that most clutch noises come from the PTO stub shaft being seperate from the crank and splined to it.
The play between these two components causes enough movement to cause a rattly noise from the clutch at or near idle.
I understand why Yamaha went that rout, as the crank bearings would not hold up to the side load created by the belt clutch drive system.
My biggest question is, how common are the PTO shaft and bearing failures and is there a certain amount of play that is not acceptable.
Coming off a 2stroke and this being my 1st 4stroke, this is new to me. This kinda worries me and would rather replace the shaft if needed then destroy the engine, plus pay for a chopper out.
I run boost and a 174 track so the PTO gets heavily loaded. THX for your reply.
Off Trail Mike
Gone Riding!
Lund:
Can't add much on the failure side, but I searched through TY and didn't find much on "spline" or "crank failure", although lots of complaints on TY about an annoying clutch rattle at idle, which is most likely coming from the spine and not the clutch. It's just the power pulse vibrations causing the spline to rattle and its on the clutch side.
Is it an issue to be worried about? Doubt it. There are lots of turbo Nytro's out there with 300+hp and lots of miles. If it was a big issue, you'd a heard about it somewhere in these forums, and this subject is pretty quiet in TY land.
All that said, I am really wondering about a viscous balancer or something else to soften the noise. Could be installed on the primary clutch cover. I find my MTX has a rattle at more than just idle, say 1200 - 5000 rpm, and for a new sled with no miles, there is a fair bit of slop in the spline. My '10 XTX has 7000 km's, almost no rattle and the spline is tight. Might have to bug Yami on this one.
What is interesting is I looked at the parts fiche for the Cat 1100 Turbo, and it doesn't use a ball bearing/spline stub shaft at all, rather a big journal bearing at the end of the crank and the usual clutch taper. Since the AC1100 is pretty bulletproof too, makes me wonder why Yami elected for the stub shaft?
Maybe just to annoy us with all the rattle and hum.
OTM
Can't add much on the failure side, but I searched through TY and didn't find much on "spline" or "crank failure", although lots of complaints on TY about an annoying clutch rattle at idle, which is most likely coming from the spine and not the clutch. It's just the power pulse vibrations causing the spline to rattle and its on the clutch side.
Is it an issue to be worried about? Doubt it. There are lots of turbo Nytro's out there with 300+hp and lots of miles. If it was a big issue, you'd a heard about it somewhere in these forums, and this subject is pretty quiet in TY land.
All that said, I am really wondering about a viscous balancer or something else to soften the noise. Could be installed on the primary clutch cover. I find my MTX has a rattle at more than just idle, say 1200 - 5000 rpm, and for a new sled with no miles, there is a fair bit of slop in the spline. My '10 XTX has 7000 km's, almost no rattle and the spline is tight. Might have to bug Yami on this one.
What is interesting is I looked at the parts fiche for the Cat 1100 Turbo, and it doesn't use a ball bearing/spline stub shaft at all, rather a big journal bearing at the end of the crank and the usual clutch taper. Since the AC1100 is pretty bulletproof too, makes me wonder why Yami elected for the stub shaft?
Maybe just to annoy us with all the rattle and hum.
OTM
Really AC has a plainbearing on pto end?Hard to believe that would hold up in a belt blowup.
kviper
VIP Member
The rattle you hear is only on the three cylinder motor's due to the pulse of the triple and is coming from the loose component's in the clutch and nothing to be concerned about. There has been shim's and O ring's used behind the button's to tighten up the gap between the spider and movable shiv with some success how ever the O ring's don't seem to last. As far as failure's go in all the year's of the triple's even boosted I don't recall ever hearing of a PTO failure even on the four cylinder's with the reduction running well in excess of 300 HP.
Zipperno
Extreme
Just another note:
The vector engine has oilflow into the spline stub shaft. Nytro engine does not....
Why?
The vector engine has oilflow into the spline stub shaft. Nytro engine does not....
Why?
