Re: 40hp Johnson 1963 Carb Question

[Don]

Neither one of those pullers is up to the task, especially the three jaw puller. The flywheel and crankshaft tapers create quite a "lock" holding that flywheel in place, especially on that 40hp.
I’m trying to remember how you have checked the ignition, will it jump a 1/4" gap while cranking? Try the new plugs, then you might want to buy some of those inexpensive inline neon spark testers/monitors, available at most auto stores or Harbor Freight.
Digging into the ignition system without confirming a problem first may just create more confusion/problems.
Again, trying to remove that flywheel without a ring gear holder and the OMC puller might get you and the equipment hurt. Let’s confirm/rule out ignition problems before pulling that flywheel.
Maybe you can post a video of the engine running poorly, we might be able to help you zero in on the problem area.