Nytro Clutch Rattle Solved ?

[m.schuey7]

Well, may have accidentally solved the clutch rattle issue with the Nytro FX

Changed my oil this fall and decided to switch to a straight weight oil, never have liked the multi weight oils, they always seem so watery when I drain them.

So after a little research ended up choosing Redline straight weight 20wt semi synthetic oil. During the warm up after I changed the oil I couldn't help but notice how quiet the sled was idling in the garage?? Normally its pain-full to listen to it sitting in the garage rattling away while it warms up. Hmmmm, must be the thicker better quality engine oil quieting things down, Wow!! Have ridden the sled twice since the oil change and all the while have been noticing how much nicer the motor (clutch) sounds. As an added test I left the sled on the trailer outside for two days after my last ride, it was single digits at night and teens during the day, turned over a little slow initially but started fine.

 

[striker606]

I wouldn't think changing oil would solve clutch rattle.

 

[m.schuey7]

Me either,

I think the fact that the straight weight is thicker and probably a better quality oil is whats having the effect.

 

[canoehead]

And in fact your running thinner/lighter weight than recommended oil.
Plus they don't recommend multi weight oil.

 

[m.schuey7]

The owners manual calls for 0w-30w which is a multgrade, its also much lighter weight oil than the straight weight 20 Redline

Not trying to start any riffs here just just pointing out that using a heavier straight weight oil instead of a multi grade does quiet the clutch rattle issue.

 

[canoehead]

You are correct but 20W is not rated for temperatures below 14 F

 

[fourload]

Redline is good stuff but it will never start below zero with that straight weight. I used Redline 0-20 in my Apex for years with great results. I will be changing over my NYTRO soon too.

 

[weldion]

I would recommend you to drain that oil out from engine. Too little protection for the moving parts in cold temps for exemple the camshaft. First it takes a long time to pump from the bottom of the engine and up to the camshaft. And the protecting film that should protect the moving parts from wear is not good enough.

So I can not recommend anyone to use this oil in their sled. Not even to quiet the clutch rattle

 

[m.schuey7]

I very rarely ride in temps that dip into single digits, and for the short amount of time it takes for the oil to heat up because its a bit thicker I'm fine with, the engine is under no load while warming up and it takes only seconds for the dry sump to have 100% pressure. All the time your using the engine hard though you have much better protection with a straight weight and 20 weight is not thick.
The reason the clutch splines are constantly hammering is because zero weight oil isn't doing the job oil should be doing IMHO
If I was storing my sled outside in frigid temps I might think again but my sled sits in a heated garage in between rides.

From what I have read about straight weights in high performance engines the level of protection is much higher than mult weights. No one use's multi weights for instance in racing engines.

 

[Keith1962]

Just came across this old thread. Any update?

 

[TPAY243]

Well you believe what ya want but the oil really doesn't have anything to do with the clutch rattle. It's the spline on the stub shaft that goes on the end of crank shaft they just loosen up over time, doesn't really hurt anything and I don't think there is an actual fix that totally eliminates its. I'm sure a thicker oil would help but not at the expense of the rest of the motor. I would use the oil that Yamaha recommends i think they know alittle more about their motors and what it needs for lubracation.

 

[4strokes]

the splines are dry, oil doesn't even get to it, its sealed. maybe the oil got in your ears

 

[Keith1962]

Wow. Dick move 4strokes.

 

[pdiddy]

If the cause of the rattle is the micro acceleration and deceleration of the crank pushing and pulling on the slack in the stub shaft then using a thicker oil makes sense to reduce the change in momentum. I'd only expect it to be able to reduce the acceleration side of the equation though.

 

[Mooseman]

Read through that long Official clutch rattle thread and lots of things were tried short of welding that stub shaft to the crank. A couple mentioned putting a heavy grease in the splines in the stub shaft. It was mentioned a couple of times but didn't look like anyone tried it.

The splines of the driveshaft slip yoke in my truck would make a "thump" whenever I stopped. Someone told me to grease the splines and it worked. I'm gonna find the thickest, heaviest, highest temp grease and give this a try this summer.