Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 50, 60, 90 & 100 Talk => Topic started by: Cruzan80 on September 24, 2018, 07:38:10 PM

Title: BS 50 Find
Post by: Cruzan80 on September 24, 2018, 07:38:10 PM
Hello All,

Just joined, as I was at a yard sale last weekend, and found a beater of a bike. Started by me looking at a dirt-bike for my son, and the seller said he was trying to get rid of it for a friend. If it didn't sell, it was bound for the junkyard. So I threw out an extreme low-ball offer, which he accepted. So for the full price of $5, it followed me home. (The dirt-bike was also $5). I have his number, and he is going to talk to his friend to see about an official bill of sale/title/etc, so I can have the possibility of getting plates for it. I am in Colorado, so hitting the end of bike season anyway.

Trying to find any/all information about this, before I start to dig into it and accidentally break something hard to find. We just moved at the beginning of Sept, so my shop is all in pieces right now anyway. This will be a slow, longer term learning experience, as it is the first (of two) bikes I will be working on.

Things I Know (and things I know are broke):
It is a BS 50 Sport, based on the model/serial number.
Right now the kickstart moves about 2-3" before stopping.
The clutch handle has broken off.
The left side cover is missing.
One back taillight is broken.

Things I am unsure of:
Looks like there is a lock cylinder up by the top right of the fork. Is it supposed to be there?
If the gas tank has any rust holes
If the muffler has any rust holes
State of motor and transmission.
Overall age of the machine.

Attaching several walk-around pictures of the bike. Any information would be appreciated, both on what I have, what is missing, possible problem areas, etc. I know the service manual is on the site here, and plan on downloading that once I start taking things apart. I am guessing the motor/transmission would be the best starting place, as if it doesn't run, that is a LARGE issue!
Title: Re: BS 50 Find
Post by: Cruzan80 on September 24, 2018, 07:39:57 PM
More walk around pics.
Title: Re: BS 50 Find
Post by: Cruzan80 on September 24, 2018, 07:42:31 PM
Even more pics. Sorry for front-loading this.
Title: Re: BS 50 Find
Post by: rwgibbon on September 24, 2018, 08:04:21 PM
Great find. Be sure to download a copy of the parts and service manuals that are free on this site.


Title: Re: BS 50 Find
Post by: bsforever on September 24, 2018, 08:49:56 PM
I agree , very nice find for sure. The 'Lock' at the steering head is a lock for the steering (anti-theft) so yes, it is okay that it is there . The other thing that i notice is the ignition switch is also not there ( the left side cover has a hole, that the switch has its face sticking out for the ignition key ) Good luck, and again great find!!!
Title: Re: BS 50 Find
Post by: Cruzan80 on September 25, 2018, 10:27:35 AM
On ebay, I have seen both the ignition switch, and the ignition coil. How would I find out if I needed both? Is the 5.6 on the last picture a reference to the resistance ohms?

Where exactly do I find the VIN on these? Found the serial, but trying to get all information I can for an official Bill of Sale so CO DOT plays nice.
Title: Re: BS 50 Find
Post by: moonpup on September 25, 2018, 10:52:16 AM
The vin number for this bike is on the little metal tag that you see in your second to last picture........ 13R018143 (June 1965 production)
Title: Re: BS 50 Find
Post by: RayK on September 26, 2018, 01:40:51 AM
As this is the earlier model, unfortunately  the front forks are not re-buildable. I think I have seen nos forks on ebay.
Cheers Rayk
Title: Re: BS 50 Find
Post by: Cruzan80 on September 26, 2018, 10:16:44 AM
Thanks Ray, going on the shopping list. When pushing down, I can get easily 6-8" of compression on them. How would I tell if they were rebuildable (in case someone swapped them for a later model version at some point)?
Title: Re: BS 50 Find
Post by: RayK on September 27, 2018, 10:41:54 AM
The fork seals are >50 yrs old. I don't know if they can be replaced on these earlier shocks as I have only seen the later model ones on 50 Sport bikes in Australia. Ask here if they can be re-built - to the best of my knowledge they can't be re-built. Check out the 50,60 gallery on this site for photos of 50 Sport models.
Title: Re: BS 50 Find
Post by: dcr on September 27, 2018, 10:57:33 AM
The "old style" forks are not designed to be rebuilt. On page 33 of the BS50 parts manual is an exploded picture of the forks. Item #2 is the inner tube that contains the fluid and seals. It is a sealed unit that can not be disassembled. For $175 you can buy the entire NOS front fork section on eBay - which is what I did when I rebuilt my 50 Sport. Richard may have one that you can buy so certainly email him and see what he has.

Title: Re: BS 50 Find
Post by: dcr on September 27, 2018, 11:06:07 AM
At the bottom of page 63 of the Owners Handbook & Service Manual in blue is the following:

NOTE: The front fork assemblies on the B/S 50 Sport model with serial numbers before 13N are sealed units. For these units the above instructions are not applicable. (Loss of fluid would require replacement of the entire inner tube assembly.)

Both manuals are free downloads on this site.

Title: Re: BS 50 Find
Post by: Cruzan80 on September 27, 2018, 12:49:21 PM
So since I am 13 R, that means I am safe to drain and refill fluid? Then if it leaks, look at 32 and 40 (o-ring and oil seal) from pg 63? Or are you guys saying that if it leaks, the seals are bad, and replace the entire inner assembly? Guessing it is easier to just buy the whole thing (ebay link) rather than find a particular section of what I am needing (inner assembly)?

Thanks for all the walking through on this guys. I do quite a bit with vintage machinery, and some general car maintenance, but this is getting into a whole new level of expertise. Once I get my garage sorted and re-wired, I will have access again to my metal lathe and mill, so I should be able to remake other small parts I need.