Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 50, 60, 90 & 100 Talk => Topic started by: stingray68 on March 07, 2016, 08:20:29 AM

Title: 1965 BS Sport 90 Engine Work
Post by: stingray68 on March 07, 2016, 08:20:29 AM

Hello All,

   Well, I have soaked the piston in this 1965 Sport 90 that I picked up and no movement yet....At this point, I am ready to pull the motor and send it off to get the cylinder work done along with piston and rings. I was wondering if anyone here has any suggestions as to what my next step should be.  I am not looking to do a ground up resto on this bike, just clean it up, get it running and ride it to work once in a while and maybe around the lake once a summer.  Thank you all in advance for your input.....Mike

Title: Re: 1965 BS Sport 90 Engine Work
Post by: Old BS Guy on March 07, 2016, 09:41:13 AM

From your description, you're probably headed to the machine shop anyway, even if you get it lossened up. One important thing would be to make sure there is nothing else locked up, making it appear it's the motor, (broken trans, clutch, etc.). I have, on occasion, loosened a stuck piston by liberally using light penetrating oil in the cylinder, then putting the bike in 1st gear and rocking it back and forth, bumping the motor. This way you're trying to move it in both directions. Using the kick starter isn't always the most effective. Best of luck, and enjoy it when you're done!

...KP

Title: Re: 1965 BS Sport 90 Engine Work
Post by: rwgibbon on March 07, 2016, 05:30:07 PM

I agree with KP. If you add oil in the cylinder and rock it back and forth,
while it is in gear, it may loosen up and make it easier to take apart.

Randy

Title: Re: 1965 BS Sport 90 Engine Work
Post by: slawsonb on March 07, 2016, 05:37:05 PM

Good luck with your project, Mike. There are many degrees of "stuckness", some will loosen with the rocking technique, others require dynamite. ;D
Hopefully yours is a "rocker".
...bert

Title: Re: 1965 BS Sport 90 Engine Work
Post by: srpackrat49 on March 07, 2016, 09:42:33 PM

i used the block of wood and a big ass hammer once.... ;D  and i,ll be damed itworked.....its most likely the rings are stuck to the walls ;D   but i have found the bottom end filled with water to on a yamaha i was going to fix..... that one is junk now... only good for some parts 8)

Title: Re: 1965 BS Sport 90 Engine Work
Post by: mqtsteve on March 08, 2016, 06:45:01 AM

I've heard of people using a hot plate(electric stove top) to warm the engine up.  After it's warm try rocking it.  You may need to get a little more aggressive.  Good luck! Steve

Title: Re: 1965 BS Sport 90 Engine Work
Post by: Ken54 on March 17, 2016, 09:56:12 AM

If you have it available, watch the History Chanel's American Restoration episode #154, where they show how they heated a 100 yr old motorcycle to loosen a frozen piston.