joshuajim
I have an 8kW that is just over 7 years old.  It has been flawless.  Last Saturday during its exercise time I noticed that there was a popping noise from the exhaust.  I tripped the transfer switch breaker to load the generator and the popping went away and the engine ran smooth.

Any idea why this occurred?
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Peddler
I would check the valves for proper clearance then if it continues replace the coil.
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Dick from Canada
Had a similar problem , checked the usual suspects ,spark plug, and air filter. Found the valve clearances to be the problem. Hope that works for you.
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78buckshot
Also make sure the intake bellows/snorkel is clamped tight and not sucking air.
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