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Discussion Starter #1
I'm new to the StarBikeForums. In Feb. 2006 I bought a new Stratoliner S. It now has 18,000 miles and it started making a bad noise when I back off on the throttle. It sounds like it's coming from the front pulley.

I searched the Stratoliner forums and found a few posts that say the front pulley nut comes loose. I'm going to check that when I get home tonight. I hope that solves the noise problem.

That's the only problem I've had with the motorcycle.
 

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I`m not a stratoliner guy but welcome to the forum. Hope you get your problem solved. the guys and gals on this forum are the best around.
 

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Welcome fellow strat owner to the all mighty star forum. You are on the right track about the front pulley nut. If it a loose nut buy a new one put loctite on it and stake it down. Oh by the way the gray strats are the fastest ones.
 

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Hey springer you got one for everybody. Where do you come up with it? I bust a gut when I read your welcome forums. Keep it up the world needs more people like you.
 

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Just curious, you mentioned a few posts on the strato forum on the loosening pully nut, did those few posts have about 18K on the clock?

Blue is fastest :eek:
Stop encouraging Springer:D
 

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Welcome to the forum sailordon...I will hold back all my squid and sub-Marine jokes for now. This is a great place for information and some really awesome people!
 

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Discussion Starter #11
Loose drive pulley nut.

Just curious, you mentioned a few posts on the strato forum on the loosening pully nut, did those few posts have about 18K on the clock?
I think all the loose drive nuts I saw reported on the Stratoliner forums occurred over 20K miles.

I pulled the cover plates off mine and found the same problem. It was hand tight for about 10 degrees. Then I had to use a wrench to remove the nut. This is what it looked like with the original nut still in place.



I'll go to the Yamaha dealer today to get a new nut. I've cleaned the threads and will use Locktite. Obviously the Yamaha design of hammering the nut hub extension into the machined slot in the shaft ain't worth diddley (or squat). :(
 

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Discussion Starter #14
No dings, no marks, no damage

So in the picture, are we also looking at "ding" marks from the pulley hitting something or somewhere against the cover?
Nothing hit anything. Perhaps the welds on the fabricated drive pulley look like ding marks.

The pulley and spline fit tight so there is no opportunity for the pulley to misalign to the point where it would hit anything.

I'm guessing the noise came from the pulley vibrating from side to side along the spline. It couldn't have been much, maybe a couple thousands of an inch. When driving, the load on the spline would provide enough friction to prevent the side to side vibration. Once you unload the spline, the noise starts.

Obviously a tight drive pulley nut is supposed to prevent the side to side motion.
 

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Discussion Starter #16
Drive pully nut torque

Good explaination. Makes sense. Do you have a torque value specified for that nut?
In the Stratoliner forums, someone posted 100 ft-lbs from the Stratoliner repair manual. I don't have the manual, but it sounds about right to me for the size of the thread. I wouldn't go too much more than that since it is a very fine pitch thread and the nut material is soft. So soft you can hammer the hub of the nut into the slot in the shaft using a center punch. That is the Yamaha design. They sure didn't put a whole lot of thought into that nut retention design. :mad:
 

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Agree, mainly because you say the nut is a softer than normal material. But on typical threaded connectors, a finer thread can take a higher torque load (if my memory serves me). Then again, this nut may have very tough threads but an annealed top for stakeing it into the slot. Soemthing tells me the threads won't be "soft".

But besides all that, I would think it would be recommended to replace the nut so you aren't stakeing it into the shaft slot in multiple spots, assuming you'll be wacking at it a new spot from the original factory dent.,....depends on the cost of the nut I suppose.
 
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