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Discussion Starter #1
I had to drill out a couple screws on my '66 honda 50 points cover, and now I am having a hard time finding replacements.

A standard metric 5 will only go in a couple turns--I don't want to force it and ruin the threads in the side cover.

Did the early Hondas use an odd size thread in places? I have the end of the drilled out screw and it just doesn't match up to anything at the hardware or autoparts stores. It measures a 28 pitch but there are no screws that small with the 28, and that seems like an american size.

Thanks,
Jack
 

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While I can't really offer any insight as to the odball thread pitch, I think the way to go would be to heli-coil it with a M5x0.8 insert. A heli-coil kit should be less than $30 and they work great.
 

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Older Japanese bikes often used the UJM (?) thread, something like Universal Japanese Metric. They used them into the later 60's on some bolts like shock bolts etc.
On non critical stuff like a points cover you could first try running a standard fine pitch metric tap in there and and seeing if a standard 5mm bolt would take a bite. The UJM thread is often so close that a modern tap will just distort the thread enough to get a modern bolt in there but not distort them so much that it destroys the threads.
Most of my Honda stuff is 67 or later...by then most of the bolts were metric standard, except stuff like the aforementioned shock bolts.
JohnnyB
 

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Discussion Starter #5
Thanks Guys,

It is a .9 pitch-- I will run a .8 tap thru the threads. As Johnny B said, it seems that several changes were made with the 67 model year.

Jack
 

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Jack- it's called JIS threading and it's all over my Superhawk. I keep most of the nuts and bolts in place so it's easy but I had to re-thread the jet holders in the carbs so currently availible jets will screw in.
 
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