Above is the dowel that sits in-between the torsion spring on the shift shaft.
When I got the quad I noticed that when shifting up or down the shifter lever would not center itself. I took apart the right side of the case and found that dowel was completely missing. I also noticed the right case didn't have a gasket but instead gasket maker so somebody was there before. I'm guessing the original dowel broke and they removed it and just dealt with having to manually center the shifter by foot.
I bought a replacement dowel but the problem I'm having now is that this dowel will not stay in its hole. After 5-10 minutes of riding it slips out and ends up under the shift shaft causing you to be stuck in whatever gear you were in.
The first time I installed it I just pushed it into the hole and let it be, assuming it's a slip fit.
The second time I took a rubber hammer and gave it a bunch of taps to see if I could press fit it. You can see right through the hold so it must taper towards the back.
Anybody have experience with this poorly designed dowel/shifting mechanism? Is this supposed to be a press fit or did the engineers really expect the dowel to sit in there all ***** nilly? In my opinion it should be a bolt with a lock washer and nut.
I'm having a buddy make the same dowel but 10mm longer. That way if it gets loose the shifter mechanism will play interference and prevent it from falling out. I also considered jbwelding the dowel in place.

 

I've had them break on a few Hondas but theirs are threaded into the case. I would guess, if it is a push fit, the hole has stretched a bit. Something like Loctite bearing fit or JB weld should hold it. A shoulder, against the case, would have stopped it moving either way, it does seem a dodgy design but must be OK on most Yam 250s.

 

Thanks for the info, I bought Loctite 21448 Green 638 High Strength Retaining Compound and hope that does the trick. I think it was originally a press fit and I'm guessing over tens of thousands of shifting cycles the hole expanded slightly.

 

By coincidence I did another Honda 420 auto this week, they seem particularly prone to it. This one took some finding, as the threaded bit had broken a third of the way down and the mechanism was still returning, just slower than normal, causing occasional confusion in the electronic control unit.

 

As a follow up the Permatex retaining compound plus the extended custom dowel seems to be doing the trick. Went for a two hour ride with zero issues. Who knows how long it will last but if the Permatex gives up the extended dowel length should keep it going hopefully.

 

May try threading both pieces

 

How is everything going?

 

I actually had to take the right case off again to look at a suspected secondary clutch issue (someone installed a fifth/extra clutch plate between the pressure plate and friction disk...no idea why). Since I was in there I actuated the shifter while keeping an eye on the dowel and it was still rock solid. Didn't seem loose at all so the Permatex must be holding on pretty well.

 

Is it solved now?

 

I would say so but I think it's only a matter of time when the Permatex gives up. That's why I already have the backup plan of the longer dowel so no matter what it will continue to work.