Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 175 & 200 Talk => Topic started by: skiri251 on November 27, 2016, 10:30:46 PM

Title: BS200RS Transmission Trouble
Post by: skiri251 on November 27, 2016, 10:30:46 PM

My BS200 developed a transmission problem.
I rebuilt the entire bike 600 miles ago. At that time I didn't pay much attention to the tranny. (Pistons, cylinders, and crank were far worse shape so I just cleaned the tranny parts, put new bearings/seals in, and assembled.) It had been working fine up until now.

The symptom is like something slipping in the first gear. It feels like the drive chain is skipping a sprocket tooth.
So it's not like false neutral. It skips momentarily with horrible noise and recovers. So far it only occurs in the first gear.

I am going to split the crank case again but I am not sure the cause will be self evident to me.

What should I look for? Shift forks? Drum?

Title: Re: BS200RS Transmission Trouble
Post by: BRT-GTR on November 29, 2016, 09:32:54 AM

        Before stripping the engine, check there is a quarter turn clearance on the clutch adjuster screw under the rubber plug,  momentary clutch slip ? I think this adjustment may tend to close up as the clutch beds in.

       Probably not a fault in the primary transmission, everything is keyed or splined and the ignition timing would go out of sync.

   Sounds like she could be trying to jump out of gear,  ( the highest torque is applied to the gearbox in first), so check the change mechanism, shift forks, fork guide pins,  drum locator, gear dogs for wear or damage. Any other causes, damaged teeth, loose parts, broken springs, etc,  should be obvious as you strip down.

    Good luck, Brian, Let us know how you go on, it helps us all.

Title: Re: BS200RS Transmission Trouble
Post by: skiri251 on November 29, 2016, 04:45:32 PM

Thanks.

My experience in clutch slip is smooth increase in engine rev. This time it's totally different.

But I guess it's so easy to try.

Title: Re: BS200RS Transmission Trouble
Post by: skiri251 on November 30, 2016, 08:53:34 PM

Update.

Clutch adjustment didn't do it so split the crank case.
Took only three hours, not bad!

And it was self evident. A broken shift fork.

I already bought used ones off eBay so should be fixed by the day after tomorrow.

Title: Re: BS200RS Transmission Trouble
Post by: hmmmnz on December 30, 2016, 09:23:52 PM

i had the same thing on my bridgestone when i stripped it,
less than 2k miles on the clock from new and it had a broken selector,  managed to get a cheap set on ebay for $10
hopefully you have the same luck

Title: Re: BS200RS Transmission Trouble
Post by: skiri251 on December 30, 2016, 10:26:22 PM

Thanks.
I got them from ebay also.