fuel pump , power pack , or something else???

[TDP523]

My boat will not plane out. Its a 1990 Evinrude 90 HP. It starts great every time but when I kick it out of neutral and add throttle it sputters a lot and will eventually die if I continue to throttle up. Motor idles fine also. Any help would be greatly appreciated. This just recently started happening. Had carbs and jets cleaned out and problem still persists

 

[MH Hawker]

Re: fuel pump , power pack , or something else???

More than likely its still carbs, those are classic symptoms.

 

[Home Cookin']

Re: fuel pump , power pack , or something else???

also likely: either air in the fuel path, or ironically not enough air in the vent. Try running from a remote tank first; if that fixes it, repair or replace all fittings and connections from the tank to the motor.

I also had the same symptoms once with a smaller motor. When you accelerate, the stator under the flywheel physically advances (moves) about a half inch. when it did, it caused a frayed wire to arc and short. So what was clearly a fuel problem was actually electrical. May as well check your battery and ground connections.

 

[racerone]

Re: fuel pump , power pack , or something else???

Start with a compression test when trouble shooting that motor !

 

[stratos150xp]

Re: fuel pump , power pack , or something else???

My evinrude 150 had the exact same issues, it was the timer base.....get a timing light, run it on the muffs and check spark, look into light and slowly increase throttle, to a third throttle or so, thats plenty good. The light should look consistant, if you have cylinders that drop out (quit firing) youll know, if you confirm an ignition issue, then comes the fun part of finding the problem, ..good luck..

 

[emdsapmgr]

Re: fuel pump , power pack , or something else???

That engine will seem to run just fine on 3 cyls. As stratos said-check to make sure you have spark on all 4 plugwires. You can use a timing light or a spark-checker tool. Keep in mind the weak ignition components tend to fail once the engine heats up to normal operating temps.

 

[stratos150xp]

Re: fuel pump , power pack , or something else???

Good point, mine was fine while it was cool, let it heat to normal operating temp before you do your checks.

 

[Bosunsmate]

Re: fuel pump , power pack , or something else???

Since it idles fine, run it on muffs to warm then pull the top two plugs off and see if it still idles, it should.
Then try removing the bottom two, it should still idle.

This helps quickly isolate down the problem

 

[daselbee]

Re: fuel pump , power pack , or something else???

Water in gas?

 

[boobie]

Re: fuel pump , power pack , or something else???

Sounds like a sticking timer base not advancing properly.