Johnson 115 (VJ115tlats) stalling problem

'93 Johnson 115 with an intermittent stalling problem. It's been on-going for awhile (across several new tanks of fuel). VRO is disconnected so I pre-mix. Most of the time the engine runs like a top with no issues, but will simply stall every so often. Sometimes at idle, sometimes at full throttle. Sometimes hot, sometimes cold. It will run for an hour or more, then stall. No sputtering, just a quick loss of power and a stall. Earlier today it stalled twice within 10 minutes, then fine for 40 minutes when it stalled again.

A quick pump of the bulb and it starts right up and is fine.

Sounds like a fuel delivery issue, right? Last week I replaced all the internal hoses and the filter on the engine with new and tightened everything down to ensure no air leaks. Same problem. Today I bypassed the entire fuel system... I used portable tank with all new hoses (and new bulb) and attached it directly to the engine, bypassing the water separator and fuel shutoff. I also had the portable tank high enough where it was higher than the fuel pump and still had the same issue.

Stator and regulator/rectifier are new (3 months old) and test fine. Carbs were rebuilt by the guy I bought the motor from 6 months ago. Although the randomness of the problem leads me to believe it's still a fuel delivery problem vs a carb or ignition problem. The only thing I haven't replaced is the pump. Any other suggestions of things to look at?

Often folks here want a magic solution.-Fact is YOU need to trouble shoot for yourself.----------Pull the fuel pump apart and inspect , then order the repair kit to correct any fault if there is one.--Maybe all you need to do is bump up the idle speed.

racerone said:

Often folks here want a magic solution.-Fact is YOU need to trouble shoot for yourself.----------Pull the fuel pump apart and inspect , then order the repair kit to correct any fault if there is one.--Maybe all you need to do is bump up the idle speed.

Click to expand...

No magic solution was requested. I have been troubleshooting this problem for weeks. Forums are a community to bounce ideas and I was hopeful someone has some thoughts on something I've overlooked.

Engine idles fine - so, not sure why the idle adjustment would remedy an intermittent stall that occurs at all RPM ranges.

Pulling the fuel pump apart is my next, logical step. Just seems odd that it doesn't happen in any repeatable pattern. All pump failures I've had have been either a complete failure or overloading with gas and generating a lot of smoke if a diaphragm fails. Also, both the rebuild kit and a new one are expensive, so I was sort of leaving this as the last item to dig into.

There are a number of pump repair kits available.-----Just buy the one you need.--Reasonably priced too.-----Run with a timing light hooked up and see if it is an ignition failure.