Ryan You might have a problem with the Tiny Tach (TT) on a point ignition. Never could get it to work on the point/condenser mag on the Yamato Y80, points probably give a dirty (not clean) signal that affects the pickup to the TT. The TT works great on the Merc 25ss with CDI system.
J6C is probably to hot a plug with the timing setting way up there. Have a set of colder J4C handy. Send me an email with your email and I will send you a PDF (11.5mb) of the Champion High Performance Heat range and Tuning Guide. Gives great tips on plugs and tuning. Key with plugs is to know how to read them. Especially important with timing set high, don’t want to burn a hole in the piston 😯 .
Pete
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