[img]i/expressions/face-icon-small-confused.gif[/img]This is going to be difficult to explain here but I`ll try my best. I hardly ever ride wide open for long periods of time and distances. Last time we wen`t riding to get to this new area there was a couple mile stretch of RR tracks we need to ride to get there needless to say it was wide open the whole way.

What I noticed was a vibration at the sustained high speed and it went something like this RRR... RRR... RRR... and so on until I let off and slowed a little. At 1/2 throttle you would start to notice, 3/4 throttle a little more pronounced and above that realy noticable. It didn`t sound like anything was going to blow up or fall apart but I think it`s something to be concerned with. Since I rarely ride like this I don`t know if this is new or been there all along.

Would worn clutch buttons do this? Maybe something is bent sprocket, wheel or axle. Rear axle bearings going bad.

Anyone who rides wide open a lot, does your purr right along or is there a vibration also?

Thanks for any input!!!

 

My machine does about the same thing. I took off the belt cover, and noticed the belt is getting worn. I suspect the belt has a 'flat spot' on it somewhere and it causes a vibration at higher speeds. My brother's 400 Xpress used to do the same thing until he put a new belt on, which cured his.
It starts out barely noticeable at top speed, then gradually becomes more and more pronounced, and starts vibrating sooner. Mine is at the point I start to hear the rrrrrrr, rrrrrr, rrrrrrr, at about 50 MPH (top speed on my Xplorer is about 60). 200 miles ago, I could barely detect it at top speed. I suspect the belt wears unevenly because it is also used as the 'clutch' and takes a lot of slippage crossing logs, mud bogging, and the like.

 

Here's another idea: My Scrambler did the same thing on hard packed trails at high speeds. Pretty much like you described. It was the Bearclaws in back making the sound/vibration at high speeds.

You never know... [img]i/expressions/face-icon-small-confused.gif[/img]

 

Its a good thought, but the treads on the tires wouldn't cause a pulsating vibration, just a steady one.
The other reason that it's not the tires is because my Xplorer makes the same vibration in High and in Low, at roughly the same RPM. As a matter of fact, it does it when you rev way up in Neutral, as well.
It has something to do with the clutch, but I'm not sure if I'd consider it a problem, as I'm pretty sure most all belt trannies with a good amount of power behind them have this same vibration.

 

my 96 xplorer did the same thing from new and i thought it was my blackwaters,till the rear axle bearings went out and after i repalced them the noise was gone.

 

Thanks for the ideas guys.

I think I can rule out the tires because I was riding on those big RR rocks and they deffinately make more noise than the tires them selves. On hard pack maybe. Xplor because mine sits long periods of time between rides I do notice a vibration from the tires getting flat spots but it`s gone after a while.

The axle bearings don`t have any slop but they still could be pitted. 4 yrs on these bearings which I think is good considering the conditions I ride. Maybe I`m on borrowed time with them now.

I lifted the rear tires off the ground and ran it the axle is slightly bent but I find it hard to believe that it would be noticable riding on those surface conditions.

I`m going to check the belt it`s been 2 years since it`s been replaced, sounds like a long time buts it`s probably only got500 to 600 miles on it.