At only $3 or $4 each, I'd definitely change the spark plugs.

And, going back about 50 years or so when I was a radio technician in
the Air Force (before I got my EE degree), a megger or a mega-ohm meter
was, at the time, a hand cranked device used to measure very high
resistance in a circuit.Â* I never saw a reasonable use for one other
than charging up a very large capacitor and tossing it to a buddy,
hoping he'd catch it.

Spark plugs have an air gap, as you know, and I don't believe using a
megger is a worthwhile test to save $10 or so.Â* Buy new plugs.

On 3/29/2020 4:49 PM, BillT wrote:
On Wednesday, March 25, 2020 at 12:31:27 PM UTC+11, Mike N. wrote:
I'll call Seminole tomorrow and see if they can troubleshoot.

I am also thinking about getting the pump rebuild lots mentioned earlier in the thread.

Thanks
I spent a couple of hours Saturday checking suggestions from this group & others. Electrical - a friend put a megga on the spark plugs & tells they're ok. Checked ignition module secondary for continuity - both ok, checked the terminal block on the engine bay firewall for loose connections - all good.
Fuel - removed the pulse line from the diaphragm pump & connected a syringe - it pumped ok. Checked carby inlets & exhaust for blockage (mud wasp nests) - all clear. I've ordered Carby diaphragms, gaskets & metering modules from SH so it may be a few weeks before these are installed. Next problem will be getting a launch to test fly - probably no operations due Cov 19. Rgds, Bill

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Dan, 5J