Fuel Restriction Alarm '93 Evinrude OceanPro 175

[Allagash]

Trying everything!. 1993 Evinrude 175 OceanPro. Good shape, runs excellent, BUT started to get what seemed to be hot horn alarm at 18-20 knots (3100 RPM plus) just cruising. Long, steady horn with hot light lit. Back it down a couple knots and alarm goes off, light stays on for a couple minutes and then goes off. Power it back up and off it goes at same speed and plane, maybe 1/2 throttle after plane. More power causes alarm to sound. Turns out to be fuel restriction with primer bulb collapsing. Traced everything from tank back, ran portable tank to isolate it to engine, not in main tank, pick-up or lines. Replaced fuel lines and bulb just for good measure. Replaced pulse-line nipple. Looking at all other possible things at engine... filters, switches, etc... There is a vac. somewhere tripping the alarm. Gonna seek to replace vac. switch at VRO pump as was suggested. Pump was new 5 years ago and has not too many hours. It has boggled two mechanics thus far. Any suggestions? I read threads and see the problem varies and is frustrating.

 

[Dhadley]

Re: Fuel Restriction Alarm '93 Evinrude OceanPro 175

Can't believe this stumped 2 "mechanics". If the pump is sucking the bulb flat the issue is NOT the fuel pump. There is a restriction upstream of the primer bulb. Could be a plugged vent or a sticking anti-siphon valve.

 

[Allagash]

Re: Fuel Restriction Alarm '93 Evinrude OceanPro 175

Yeah, seems fixable, but for whatever reason (and I am no mechanic) they can't isolate the problem. I have heard that the anti-siphon valve isn't the issue... where are the 'vents' you reference? The problem persists with use of a portable tank, so it is at the engine. How many things could it be? Is the thermostat at all a possibility given horn goes off and 'hot' light is lit - maybe engine thinks it is hot when it actually isn't or does flat primer bulb mean it is solely a restriction?

 

[jonesg]

Re: Fuel Restriction Alarm '93 Evinrude OceanPro 175

If the problem persists with a deck tank then its the bulb.
Make sure the arrow points toward the engine...or swap it out for a nice genuine OMC bulb. If your fuel line is old it can collapse internally, swap the whole lot out for new alcohol resistant hose.

 

[Allagash]

Re: Fuel Restriction Alarm '93 Evinrude OceanPro 175

Ran a portable tank and bypassed the lines and bulb altogether. Still occurring, so that rules out inboard tank and lines and bulb. Also replaced the lines and bulb with brand new OMC because they needed it.

 

[Chris1956]

Re: Fuel Restriction Alarm '93 Evinrude OceanPro 175

Are you using 3/8" fuel line, fittings and filters? I did not think the '93 models had the Check Engine (Fuel restriction ) alarm.

 

[Chris1956]

Re: Fuel Restriction Alarm '93 Evinrude OceanPro 175

My mistake. The parts list shows the vacuum switch.

 

[Allagash]

Re: Fuel Restriction Alarm '93 Evinrude OceanPro 175

Yes, 3/8, proper OMC. It does has the Vac. switch (which is on order) and a steady alarm (just like the hot alarm) for a fuel restriction. Odd, because fuel restriction alarm and hot alarm are the exact same thing. The 'hot' light even lights, but it isn't heat. Yesterday, alarm went off at 15 -17 mph consistently but backing it down and throttling up, I was able to get past the alarm for a spell and ran it at 3/4 throttle without the alarm. Fuel restriction looks to be only a certain speeds under certain load.