Occasional false neutral at 4,500-5,000 rpm

[Twempie]

2003 R1150R Single Spark, Non-ABS, just over 39,000 miles.

During the past couple of weeks, my bike's been popping out of gear during hard acceleration.

It's only happened a handful of times over the past few weeks, usually while accelerating on a freeway on-ramp, in 4th or 5th gear, over 4,500 to around 5,000 rpm. The bike pops into a false neutral, I put it back into gear, and continue on my way as usual.

Today, as a first step, I changed the FD and tranny oil (it was due), using synthetic 75W-90.

Anyone have any experience or ideas of what I may be dealing with?

Thanks.

[boxermania]

Generally speaking a tranny poping out of gear is usually related to:

Looseness of the shift linkage
Damaged or bent shift fork

May I suggest that you check the plastic bushing that is located between he shift lever shaft and the tranny housing. It is located right behind the gearshift lever. When worn, they have been known to give problems.

This is the simplest test before getting serious with the tranny.

Keep us posted........

[AndyRR]

Is it possible that the clutch is slipping? Is there a clunk or do the rpms just climb without any other noises?

The fit between the gears and the shift forks is very tight. Just enough for a layer of oil. It's possible that there is a lot of slop with one of yours. When you drained the trans fluid, did you use the drain plug on the side or underneath? I have never used it, but the underneath plug is magnetic and any metal filings should be caught there. I'm not sure if there is an aluminum gasket on that plug - the parts fiche doesn't show one. Drain the fluid from the side plug first, so the oil doesn't wash any metal filings away, then pull the lower plug (it's very close to the normal drain, but underneath).

Has anyone actually used the magnetic drain plug? I didn't even know we had one until I was putting my trans back together and the manual told me to clean it. I cleaned mine from the inside, so it still hasn't come off.

Boxermania - I can't picture that plastic collar. If I ever had one, it didn't go back on the bike. I'm going to go search my workbench now...

[dmk]

I've had this happen to me in the middle of a 1,500 mile trip. I had 12K on my bike and it happened twice - I couldn't find a dealer to check it out because I was in the middle of nowhere. I called the nearest dealer and he wasn't much help, implying it was likely the clutch spline that we've heard so much about. I had no choice but to continue on and it never happened again. I've put 5,000 miles on since then... hoping it never comes back. Please post if you find anything else, I'm still terrified it may be the dreaded clutch spline issue.

[sweatmark]

Ditto for the clutch slip idea.

Could be worth time & effort to pull starter for peek at clutch to evaluate fluid contamination.

[Twempie]

I tried to repeat the problem today, but the bike behaved itself. Thanks for the input, I'll check out the suggestions and post any findings.

[boxermania]

AndyRR

Go to ascycles.com, Fiche for R1150R, Diagram #23, Item #9....sleeve, that's what I was talking about.

Albeit, it can be many other things and I agree with you that it could be internal looseness. I'm not a beleive of preloading the shift lever prior to gear changes.......they tend to put undue loads on the engaging components and that eventually results in excessive wear.