Hey experts:
May have a transmission issue here.
There has been a couple time when gliding in neutral that the bike motor has suddenly stopped with a clunk. Like it whacked into a gear when it wasn't shifted and the motor just stopped. Bam. Not all the time. Infrequent.

And, now notice a 'whirr' sound when letting off the throttle from speed that happens around 3500 to 4500 rpm. Mostly noticed when the bike is chilly, not warmed up. Pulling in clutch doesn't make a difference, even when the 'whirr' is happening. Even with a throttle blip with the clutch in. Tranny is what I'm thinking. Thoughts?

 

Sounds strange, Scott. However, I'd think you'd get a change in that "whirr" noise with either the clutch in and out if it was in the clutch or tranny. I'm assuming that noise is not just happening in neutral.

On your tranny seeming to go into gear from neutral, have you had any crashes lately on the shifter side? Is your shifter rubbing anything? Have you changed the angle on the spline for your shifter? Do you have some new boots?

 

Strange? Yes. Very. No change in the 'whirr' with clutch in or out. It happens when I'm slowing down, like for a stop light. Riding along at 35 or 40, let off the throttle, slowing down, 'whirr' for about 2 to 3 seconds. Speed up, it goes away. Clutch lever in or out, no difference.

Ya, I've probably crashed into the shifter. And the shifter isn't stock. A MSR which is more solid than the stock shifter. No, it's not rubbing anything. No change in angle. No new boots. This is street riding with no pressure on the shifter. The bike did take some good hits both left and right side in the last month or so in the Owhyee rocks. I thought most of the hits were to the skid plate, but the shifter could have been hit.

But the whack motor stop started before these hits. As example, pulling off the road, into a gas station, shift from 2nd to neutral and glide into the fuel bay (something I've always done since the street riding days...is this a bad habit?). During the glide, suddenly the motor just slams to a stop with a "klunk" sound, like it was jammed into gear with the rear wheel locked up. It just whacks to a stop. But the rear wheel/chain doesn't jerk or anything. Glide to a stop, hit the starter, and it starts right up.

Are they related? Heck, I don't know.

I was ready to do 351, but don't want to invest in the BB until this crap is diagnosed and fixed. Where do I start?

 

Not reassuring You would be the first I see here to counter the legendary reliability/robustness of this KLX. How many miles on yours?

Not an expert, but I would suggest flushing the oil and looking closely for metal in it and in the oil filter.

 

If you start the bike in neutral, does it ever want to surge forward? I had similar issues with my banshee transmission. It ended up being a fried transmission bearing. For me, it got to a point where the bike no longer had neutral. At which point, there had been extensive damage to the transmission shaft (welded bearing to shaft). I dont know about these klxs, I've never had to open my bottom end, but my shee would have been a $50 fix if I would have caught it in time.

 

[QUOTE=IDRIDR;458815]During the glide, suddenly the motor just slams to a stop with a "klunk" sound, like it was jammed into gear with the rear wheel locked up. It just whacks to a stop. But the rear wheel/chain doesn't jerk or anything. Glide to a stop, hit the starter, and it starts right up.

QUOTE]


My Sherpa will sometimes make this noise when shutting it off. I've always wondered what it was.

12,500 hard miles and counting.....

 

no, it doesn't. And this clunk-stop in neutral has happened 2 or 3 times over the past few months. The whirr is regular when cold. Thanks, will put a bearing on the list of possibilities.

 

When you are coasting in and the engine locks and you have neutral... does the engine end up in gear? If no, I would say it is not anything on the wheel side of the clutch (including the transmission).

While trail riding, I notice when I stall on the big hills & in rock gardens that the engine stops with a big clunk and then we start the balancing act. If the above paragragh is true, I would look at the ACR unit, as that kicks in at low RPM and the engine dies abruptly. It may have a bad spring or something loose, or it may be adjusted to activate in your idle speed range. Adj you idle up may test this idea.

 

That was my first thought. It does sound like a whack. Take your wrench out and the crank plug, and turn the engine over slowly with it. Every other rotation, you will probably hear the ACR make a noise. Is that the same noise?

 

There may be an issue with the starter sprag clutch...

Ron