Warning: Kickstart Stopper Breakages

I recently bought a 1999 WR400 and on the ride home the kickstart ratchet mechanism jammed on. After a little research I discovered this was due to the kickstart stopper [Part No. 5BE 15668-00 which bolts to the r/h crankcase behind the clutch] wearing out - and it seems to have affected a few people on this forum in the past. The stopper is designed to prevent crankcase damage in the event that the kickstarter kicks back. However, and the reason for this post, when I went to replace the stopper, I discovered that not only had the stopper completely worn through, resulting in a large chunk of the crankcase being chewed off, but also the securing bolts had stretched - one so badly that the head was about to shear off - which of course would have caused massive engine damage. A previous post on this forum reported that the bolts had actually torn the threads out of the crankcase. This leads me to believe that in certain circumstances, when the stopper has worn though maybe, that there is very significant perpendicular force on the securing bolts which causes them to either fail or tear out of the crankcase.

The bike has covered 10K's and therefore I would strongly advise that when you take the time to undertake a spot of preventative maintenance, and check out this particular component. By the way, all the parts are identical on all WR/YZ 400/426 - so be warned it could happen to you.

Also, take care when starting the bike to make sure that that you try to not allow the kickstarter to kick back - I think caused by being a bit eager with the throttle when the engine first fires up. I'm sure that my poor starting technique [2 stroke convert!] finished the stopper off, BUT the wear had definately built up over a long period of time!

I have some photos showing the location and damage caused, but being a bit of a luddite, I'm not sure how to post them.

Thanks for the heads up.I'll check mine out.

I have some photos showing the location and damage caused, but being a bit of a luddite, I'm not sure how to post them.


Send them to me and I would be glad to host them for you.

I would love to see them myself.


p.s. thanks for the tip off

Mine broke the day after I got the bike. (I bought my '99 used in April 2000 from a dealer.) The threads were actually ripped out of the case. It broke again in January '01 because the dealer didn't fix it right the first time. All they did was just helicoil it and send me on my way. They paid for a new set of cases for me.

Now I check the kickstarter stopper for wear every time I take the right side cover off.

I think there is definately some sort of design problem here. Firstly the stopper itself simply isn't strong enough - it's a skinny little bit of steel probably no more than 0.5mm thick. Secondly, I don't understand why there is so much force being placed on those securing bolts. I can only assume that it is when the stopper wears out and the force of the returning kickstart acts directly perpendicular to the the bolts - a classic shear force - I did notice that the stopper had worn thorugh right on the bend - thus turning the stopper into a guillotine.

It has has already spolied the "ownership experience" for me, especically when I traded up from a 1992 Honda CRM 250 that never ever gave me any trouble. Pity, cos the WR itself is a terrific ride.

Here are the photos I took [Thanks to Darin for hosting them for me!]:

web page http://home.cleanlink.net/enduro/TechInfo.htm

Just scroll down and click on the broken kickstart stopper link.

Picture 1 shows the exact location of the stopper plate on the right hand crankcase. You can see the damage caused to the crank case after the stopper failed.

Picture 2 shows the extent of strip down required to get adequate access. Unfoprtunately you cannot avoid taking the clutch off, but I did leave the water pump intact in the r/h crankcase cover. Took about 3 hours to diassemble and reassemble - but I was taking it slow and being very careful

Picture 3 shows the damage. You can see the new stopper at the top of the picture and the damaged one at the bottom. Also shown is the top bolt which is exhibiting severe signs of stretching. Luckily the threads were not damaged but I did re-tap them just for good measure.

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