Engine miss while riding

[kywinger]

Can't seem to find a solution for an engine miss. 138K, with 3K on carb overhaul, all new gaskets - O-rings - CV diaphragms - air cutoff valve - vacuum/fuel hoses - spark plugs - spark plug wires & caps – air & fuel filter – sync’d the carbs. Bike was running very strong.

While riding the engine started to miss and cleared after 15 miles. A week later the engine started missing again and will not clear up. The miss decreases under accelerating load and then comes back when leveling off at a constant speed. The engine seems to idle fine, starts to miss when opening the throttle to start moving.

Since the bike was performing so well I can’t pick a good starting point. Anyone have a good idea of where to start investigating.
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I don’t see the coils being affected by opening the throttle.
Do the pulse generators fail catastrophically or flake out slowly.
Also, has anyone tried moving the pulse generators to the engine front of an 84 GL1200.

[cwalsh]

I would think a hairline crack in a coil that was allowing the coil to arc to ground could be an issue.

[bs175dths]

A great way to test for cracks and arcing from the coil body is to remove the shelter and run the engine at twilight or in the dark. You may enjoy the light show, but it is an indicator of required repairs.

As far as the performance problem, it may be your fuel delivery is causing problems. Most likely the fuel pump may not be performing as it should across its operating range.
Idling fine: the pump can maintain delivery
Gettin' On the Juice: the pump can maintain
Maintaining speed: it may give a hiccup now and again, or, it may just have a sweet spot where it doesn't like to work as it should.
I am not aware of any sort of test other than at idle, but maybe, if the pump is original, she might be getting tired.
Used factory pumps are cheaper that new, but sometimes, not by much.
Some folks have had success with a Honda Accord fuel pump.
Still others have used the Mr. Gasket fuel pump.

If you can, replace the pump with a known good one (easier said than done) but it is worth a try.

-Ride On