Friggin Motor....88 SPL dying at WOT :(

[TPD211]

OK, As some know I just bought a 1993 Deckboat powered by a 1993 88 SPL motor. <br />We fixed the primer leak last week, it ran fine after that.<br />This morning I'm out with the family on the lake, it runs fine. We did no WOT runs, just 3k rpm or so.<br />After I dropped off the family the wife heads over to the marina in the SUV and I am to meet her there so we can trailer the boat back to the residence. <br />Enroute to the marina I'm WOT, its running fine. <br />Then is starts to loose rpm as if gas starved. I hit the primer, rpm's go to 5k and stay as long as the primer is held in. It was cold here this morning 50 degrees or so. <br />I back off the throttle to 3k or so, it runs fine. <br />Later I check the fuel filter (round one) at the fuel punp, it is clean. <br />There is no in-line fuel filter, should there be one?<br />I check the fuel lines, one small fuel line that runs from the bulb to the water seperator has hair line cracks in it. Could this be the cause of the gas starvation thru air leaking in at WOT? I will change this small line this week anyways. <br />I checked the plugs, they were nice and tan. There was carbon on the outside edges of the plugs but the insulator/tip was nice and tan and all 4 looked even.<br />Any suggestions? Its for sure gas starvation. I'm guessing a air leak somewhere as it looses power only at WOT. <br /><br />TIA

 

[walleyehed]

Re: Friggin Motor....88 SPL dying at WOT

Yea, sounds as though you're not getting enough fuel....Tank vent fully open????<br />Check all fuel line clamps as well.<br />If this don't work, fuel pump diaphram may be getting weak....

 

[walleyehed]

Re: Friggin Motor....88 SPL dying at WOT

Primer solenoid just bypasses some fuel from the pump directly into venturi......hhmmmmmm... That's by-passing the main fuel circut, so maybe floats are set too low, or trash in jets????

 

[TPD211]

Re: Friggin Motor....88 SPL dying at WOT

Ummmm, tank vent?<br />Is that the small cap next to the gas cap?<br />I will check the fuel line clamps.<br />I will probably replace the diaphram and look at the carbs and see if they need a kit.<br />I have a can of the evinrude carb cleaner you use thru the primer valve, maybe Ill give that a shot.<br />So far it looks like:<br />1) Check fuel lines and clamps<br />2) Replace diaphram<br />3) Inspect/repair carbs with a kit<br />4) Decarb the engine clean carbs as needed.<br />5) Buy new motor...... <br /><br />Anything I miss? <br /><br />TIA

 

[walleyehed]

Re: Friggin Motor....88 SPL dying at WOT

I'd look seriously at the vent first. when you hit the primer, and engine picks up RPM, it's not getting (enough) fuel through the main fuel circut. Floats and checking the correct float-level setting would be something to consider next. Put new fuel lines from pump to carbs, before you hook them to carbs, turn the engine over and see that fuel is coming out both lines.