Can anyone shed some light on JIS fasteners for pre1967 Hondas? Particularly 305 Superhawks, Scramblers and Dreams. I am use to 1970s JIS screws with the small dot on the head of the screw. I read somewhere that the pre 1967 JIS (no dot on the head) have a different thread pitch .....9 compared to 8 pitch on the newer JIS fasteners. Is this correct ?? The reason for my inquiry is I want to replace some of the current damaged screws on a Superhawk. Thanks for any help or pointing me to any reference. Sounds like I'm becoming a fastener nerd !:lol:
Pre 1967 JIS fasteners
- Thread starter Yakeye
- Start date
IIRC the earlier version was ISO threads but someone far more familiar with the older models will have to confirm or refute my old-ass memory.
WintrSol
Veteran Member
If you have one out, measure 10 threads. Use a metric scale or a vernier that reads in millimeters. Divide the result into 10 to get the pitch in mm. If it is ISO threads, switch to the ISO (inch) and use the same math.
ballbearian
Veteran Member
You are correct that the 5mm screw pitch changed from .9 to .8 and there are no dimples on the earlier ones. The 6mm bolts /screws didn't change. The countersunk cross head screws on the points cover and stator covers are the hard ones to find, the originals have a slight dome and are chromed. I try to save these by gently peening them smooth and hold them in soft jaw vise while pounding in a JIS #2 tip and them finally buffing on a wheel. Belmetric Fasters have a very limited selection of these courser thread screws but without the chrome and the heads are totally flat. The points plates are also like this and you will find the 4mm ones there (usually slotted) as well as the 3mm tailight lense screws.
The one I found difficult was the tiny screw on the chrome cover over the steering lock on the 1966 CL77. I ordered two different thread pitch screws from CMSNL and neither fit the cast mounting in the lower triple tree. I ended up using the original screw after a clean up, since it was correct. When the pitch gets to .5 or .6 .7 or .8 TP it is hard too see with these old eyes, if the metric gauge fits or not.
ballbearian
Veteran Member
The one I found difficult was the tiny screw on the chrome cover over the steering lock on the 1966 CL77. I ordered two different thread pitch screws from CMSNL and neither fit the cast mounting in the lower triple tree. I ended up using the original screw after a clean up, since it was correct. When the pitch gets to .5 or .6 .7 or .8 TP it is hard too see with these old eyes, if the metric gauge fits or not.
I didn't think of those little 3mm. They might be the same as the emblem screws on the tank covers.
Chris I have scanned the CB77 manual but totally missed this info. I was not aware of this excellent chart and description. Thank you for providing this. Does this affect your 450 Black Bomber bikes since they were produced in 1965-1969?
Thank you for the Belmetric link. I will check it out. Maybe the only place to find the 9 pitch screws if originals are impossible to find or cost prohibitive.!