Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 350 Talk => Topic started by: Kenneth Pagel on January 22, 2021, 01:19:03 PM

Title: Seat Mounting Bolts Needed
Post by: Kenneth Pagel on January 22, 2021, 01:19:03 PM
... for my '67 GTR. One of p/n #0142-1220 hex bolt "D" (LH side of seat), and one of 09511-145 (12X45) for the RH side of the seat. NOS, or very good used. Odd that the parts catalog lists two different sizes, since the frame mounts for the seat appear identical, as are the seat brackets. PM if you have a spare set. Thanks!
Title: Re: Seat Mounting Bolts Needed
Post by: erniegroen on January 22, 2021, 02:23:09 PM
LH bolt is also intended to fix the handle and collar!
So LH M12x1.50x45    RH M12x1.50x20
You can take standard bolts, but the head size will then be 19mm. instead of 17 mm.
Good luck with the restoration, Ernie
Title: Re: Seat Mounting Bolts Needed
Post by: Kenneth Pagel on January 23, 2021, 11:55:41 AM
Thanks erniregroen. I forgot about the lift handle! You mentioned that I could use 19mm head "standard" (meaning metric?) bolts instead of the 17mm head original bolts, but arend't the original's JIS thread? I THOUGHT I kept all of the original hardware that was in good shape, but have been unable to locate them. :-\.
Title: Re: Seat Mounting Bolts Needed
Post by: erniegroen on January 23, 2021, 01:28:39 PM
Hi Kenneth,
JIS and later the ISO standard used in Japan is metric! The big difference is that Japanese motorcycles use a different pitch for the M10 and M12 bolts! ISO M10x1.50 M12x1.75 and in Japan: M10x1.25 and M12x1.50 pitch. The last 2 measures are common in Europe as fine metric.
The biggest problem with JIS screws ( till 1967) is M5. JIS= M5x0.9 and ISO M5x0.8 pitch. I'm not sure, but it's possible that the later Bridgestone's use M5x0.8 pitch.
I bought a Suzuki T20 in 1966 and it still had JIS M5. In 1968 with my T500 this was already ISO
Fortunately, taps and cutting plates can be purchased for this for little money so that you can make bolts yourself or search on Ebay.
Title: Re: Seat Mounting Bolts Needed
Post by: dfc on January 25, 2021, 07:32:57 AM
Were the shocks mounted in the rear position? If you are also missing the handle spacer that may explain...
Title: Re: Seat Mounting Bolts Needed
Post by: Kenneth Pagel on January 25, 2021, 12:22:56 PM
dfc: Shocks are mounted in the forward position.
Title: Re: Seat Mounting Bolts Needed
Post by: dfc on January 25, 2021, 11:03:43 PM
Kenneth: Was just a thought, as that is why I am missing the separate seat bolts. Thinking to try the forward shock position.