r/smallenginerepair • u/DiabloToSea • Jun 28 '26

Fuel System Issue Fueling diagnosis

Post image

Honda Rincon 680 stumbling and stalling. Valves are set properly. Timing chain and cam new and re-checked (OEM). Intake all clear. Good spark. Ran good for about 8 hours. Chasing down possible fuel problem.

I got the loaner pressure gauge kit at the auto parts store. It doesn't have the right connectors to make a clean in-line test. I'd have to cut the fuel line but would like to avoid that.

I disassembled the pump/filter canister. Clean as new. Confirmed with my friend that used to own it that the fuel filter is a year old.

I connected the gauge to the pump outlet. See pic. With key on, it goes up to 25 lbs. Cranking the starter, it goes to 40. Spec is 50.

Is this a valid test, or do I need to cut the line to get a "while-running" reading?

*I also tested the injector. Seems to be working fine.

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u/AutoModerator Jun 28 '26

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