I think you're paranoid...but that doesn't mean they're not after you.
Seriously though, once you know you've got the 'good' design star installed, I think any fears of breaking it can go away. I'll explain my reasoning...

From the layman's standpoint, I've scoured the internet (so to speak) in search of information on broken shift stars related to this family of bikes...nothing comes up other than the 09+ KLX250S. Nothing on the older KLX250S, nothing on the KLX300, nothing on the KLX250R. A lot of history there, but the issue of broken shift stars doesn't occur until the '09 KLX250S comes out.

From a professional standpoint (I'm a mechanical PE), I blame the rash of broken stars 100% on a design flaw in the 09+ star. That relief cut - whatever the reason - does a number of things to make the pins of the star weaker on their own, plus the way the shift mechanism fork contacts those pins compounds the problem. Long story short, breakage of the 09+ design is more or less inevitable, but the 06/07 style will not likely ever break. With the good design, I think you'd be more likely to shear the dowel pin that locates the star on its shaft - and I still think that's very unlikely.

Now that I've said that, remember Murphy's Law! That star isn't such a large item to pack anyway.

 

hey
i just got by bike back today from breaking the shift star on my klx 250 2008 australian/ new zealand model. as had no idea about this sort of thing i took it into our local dealer. don't no which one they changed it to hopefully a stronger one cause it was a pidly little crash that broke it.
thanks for the thread interesting to see other people had same problem and what caused it.
mike

 

IIRC there was mention of the shift star profile on the planetklx site, saying the 06-7 shape has some problem, and to reshape it for better shifting. There might be something on Brewster offering to modify them... I could be wrong memory fades in winter

 

Now that you mention it, I went back through my subscribed threads on this site, and yes there are some folks who complain of shifting issues with the 06/07 style shift star.

I've been thinking about this more and more, and I'm starting to think that the increasing the spring tension on the detent arm (as done by adding a dowel in the KLX300 shift star mod) will play a more important role than it's credited for in helping to avoid missed shifts or the tranny slipping out of gear. A lot of things play into how the whole mechanism works. I've got to run now...I'll try to get back here later to elaborate.

 

Lutz:
I'm interested in hearing your thoughts. IIRC, the earlier posts had to do with grinding the "groove" deeper for a better lock into the shift position.

 

I think that train of thought is very much in the right direction. It's the same train of thought that makes me think we need more spring tension on the follower.

We're getting into a balancing act between shift 'smoothness' and shift 'positiveness.' Thoughts are circling in my head...but I've not enough time right now to try straighten them all out and type them.

Good night everybody (or good morning if appropriate in your part of the world).

 

So here we go again...

I think with the 'pointy' shift stars (such as the modified KLX300, OE '06/'07 KLX250S, and OE '08+ KLX250S) we have a lesser of evils. That is, the sharp point of the star makes the follower less likely to hang up in a neutral or false-neutral position; however, the flatter profile of the side of the star makes the detent positions much less positive - less likely to fully engage and less likely to remain engaged.

For what it's worth, Kawasaki used the same general profile for the star in the KX-series two stroke motocross bikes as was used in the KLX300 - the type with the 'clipped' tips and defined valleys, rather than pointy tips and shallow valleys. The KX bikes had some degree of shifting 'issues' as well, but the common solutions do not involve modifying the profile of the shift star - rather options 2 and 3 below are commonly used, and sometimes 1 as well.

It seems the simplest remedy for our bikes is simply increasing spring tension on the follower (a la the dowel on the spring). However, there are a number of things that might be done to greater or lesser degrees of extravagence to improve shift quality.
1. Increasing tension on the follower.
2. Polish contact points on the shift star and the pivot point of the follower arm.
3. Polish the shift shafts and shift forks (inside the transmission).
4. Attempt additional modifications to the star profile to create more positive detent positions (valleys).
5. Develop a follower with larger-diameter, lower-friction roller (possibly ball bearing). This would likely go hand-in-hand with a matching refinement of the star profile.

 

Yeah I had read on here awhile back, before I got my bike that the 09 star was weak, so I knew (or hope I know) exactly what happened when I had a low speed get off and dropped the bike on the left side. Finished my rock star endzone dance, picked her up, straightened the handguard so I could pull in the clutch lever, then cranked the dirty girl up and nearly fell over when I gave it some throttle and eased out the clutch and I didn't take off. Worked the shifter up and down with no gear change.

Mine had issues shifting sometimes before, so I hope the new star makes her shift better. Thank you all for posting, so I wasnt too freaked out and had an idea.
Aside from the obvious, worst part was getting towed over a bunch of low berms by my buddy and getting pulled into the ground on the way back to the truck.

Nevermind this small problem, still love the dirty little *****.

Big Bend or bust!

 

If and when this repair is needed I think I will go ahead an buy two 06-7 shift stars. Modify them both to the same shape as the 09 star. The damage happens so easily when crashing on the left side, my buddy laid it over doing about 15 mph.....

 

Newbie with 09 klx250r and researching some of my issues with shifting that may be a symptom of a failing or worn shift star...looking for some advice. When I'm riding with bike hot or cold.....on occassion when I'm coming to a stop and down shifting, sometimes I will not get into 1st gear...i will have to play with the shifter and sometimes have to let out of the clutch a little to get her into 1st gear to start out again.

Shifting from 1st to 6th is no problem at all and very smooth...it's just once in a while I will be sitting at a light and trying to shift into 1st gear. I have found that if I downshift while moving coming to a stop it usually goes into 1st gear everytime...its just if you are sitting there it might not get all the way into neutral or 1st......thoughts? oh, i do know how to ride and shift and the clutch is in great condition (2000 miles on bike). Oil is 10-40 synthetic and recently changed.