90 115 Johnson dies at WOT

[hunt-fish.com]

Not sure why the motor started dieing after a minute or so at WOT. This went on for several tries then went away. Fuel obstruction? Air leak in the fuel vacuum? I'm' going to retry today. Motor appears to be running fine.

 

[Texasmark]

Re: 90 115 Johnson dies at WOT

Beins you have 4 carbs and if one or two, maybe 3 fail the engine should continue to run somewhat; not die, I'd say you are looking at a supply problem. Possibly, as you said, there was air in the fuel line or maybe some crud in a fuel filter and the fuel pump was sucking a vacuum on the line till it cleared.

Other thing it could be is if you added any water absorbing agents (alcohol based) to your tank the alcohol could be blending with water in the tank and making a milky goo that could have gotten sucked into the tank's fuel filter and blocked it. Stopping the engine allowed it to float off somewhere else. If that's the case, it'll be back to haunt you. BTDT

Mark

 

[hunt-fish.com]

Re: 90 115 Johnson dies at WOT

Thanks! Only 2 carbs. Checked all hoses that I can see. Since the boat is 15 years old I'm thinking there may be a broken plastic hose clamp on the fuel line between the fuel tank and the brass fitting on the splash area where the primer bulb fuel line connects to the boat. I've had several of those plastic hose clamps in the motor break over the years. The only problem is the fuel tank is built in and I can't get to the fittings without removing the back deck of the boat. It's a Cajun 175 fish-n-ski.

Also, the fuel here in DFW has Ethanol mixed in due to EPA regulations. Not sure how that effects the motor.

Like you said it could also be junk in the fuel that let loose since the boat hadn't been run in a couple of months.

John

 

[tashasdaddy]

Re: 90 115 Johnson dies at WOT

i think you found the cause of your problem, ethanol. looks like it's going to cause everyone problems.

 

[ezeke]

Re: 90 115 Johnson dies at WOT

Your 1990 motor was designed to operate OK with ethanol.

The first thing you will want to be sure of is that your engine is not overheating when it starts to cut back on you.

 

[hunt-fish.com]

Re: 90 115 Johnson dies at WOT

I was curious about the ethanol, good to know it's OK. I know it causes my truck to get worse gas mileage.

No indication of a heat problem. Pee streem is cool and no warning horns. I think it's bad gas, ethanol or not being the cause. Fresh tank yesterday did the same thing. Now running rough even at idle. I think there was some junk in the tank or something that got stuck in the carburator. I put some Penzoil marine fuel cleaner conditioner in the tank. Just to make sure I ran a spare tank with a separate fuel line. In the separate tank I put about 1 oz of marvel mystery oil in 1 gallon of gas to see if it would break down the junk. Looks like it worked initially it was running rough. After a few minutes on the separate tank it smoothed out. Switched back to the built in tank with the conditioner added and it kept running smooth. We'll see what happens when it get it to the lake.

Thanks,
John

 

[OBJ]

Re: 90 115 Johnson dies at WOT

John....make sure the built in tanks vent is open.