Johnson OA-55 flywheel puller bolts 1/4 – 24?

[twostroke]

I just went to pull the flywheel off an OA-55 I picked up yesterday. Pulled the rope sheave & crank nut off, grabbed my puller & bolts…..and it appears that the holes are 1/4 -24 thread, if I’m reading my thread pitch gauge right. Am I correct? I vaguely remember finding some of this size on a old Harley that I did some resto work on for a guy back in the day. Any ideas to save me byying a sack of expensive scooter hardware to use only three would be greatly appreciated.

Thanks!

Jim

I say "pardon me" a lot. I had a 20H, then raced open mod sleds.

[Mumbles]

Your motor was built in a time before thread sizes became standardised and manufacturers could use whatever thread they wanted. Those threads aren’t 1/4-24 but close. They should be 14-24, which is just a few thou under 1/4".

Here’s a link to a previous thread on these threads:

viewtopic.php?f=2&t=14362&p=75091&hilit=14+24+threads#p75091

[twostroke]

Thanks, Mumbles! Learned something there….I always thought that 1/4" and #14 were the same…

Tubs told me how to make a flywheel-popper-offer which worked great. Nut w/bolt welded in, tighten on crank, lift flyweel and two whacks with a hammer…

Now I’m on a mission to find a coil. My new Merc-O-Tronic says it’s bad.

I say "pardon me" a lot. I had a 20H, then raced open mod sleds.

[lyks2tinkr]

Nothing against your new mercotronic but what is the secondary resistance of the coil?

Johnson coils are pretty robust and still throw great spark 80 years later unless it got damp.

I have an OA55 that I restored over 10 years ago and it is a fantastic reliable runner. I haven’t had the flywheel off since then.

[twostroke]

What kind of a number do I want to see measuring secondary resistance? I’ll check tonight when I get home.

Jim

I say "pardon me" a lot. I had a 20H, then raced open mod sleds.

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