1989 Evinrude XP E150STLCEM intermittant power loss/gain

[Bassalive]

Good morning,

I took out the old Stratos to a tour Saturday, and my XP 150 fired right up after the ignition switch, and primer solenoid issues were solved
With guidence from you guys last season.

Our draw # came, and I put the hammer down, and the shooter prop took me out of the hole. As I trimmed, the RPM's climbed up past 4700-4800 ish as did my speed to around 48.6 mph and just when it was gonna jump the last hurtle she stumbled.
The rpm's dropped for a second, and you could feel it kick in again then stumble.

It was like a cylinder was loosing spark?

Today is diagnosis day, but before I dig out any tools, I wanted to run it past you guys.



-Has a newer power pack/wires/coils
-pre mix fresh gas 50:1
-new plugs last Season

[omcforever]

Try pushing the choke/enricher next time it does it and see if it runs better. If so, fuel issue. If not, electrical/ignition.

[Bassalive]

Ya know on the way back from the River on the weekend I thought that.
That't usually when I think of things or wake up in the middle of the night, and have a "Ureka" moment.
I'll try pushing the key for primer during the next on water run when it does it.

I also need to confess I haven't replaced the low pressure electric "Facet" fuel pump the previous owner installed with a Max Rules.
I kinda had sticker shock when buying one in CND $$$..., but will if you think that may be the culprit or is attibuting to the hiccup.

The fuel comes from tank to a clear inline filter I installed, to the bulb, then on to the pump, from pump to tree.

Giving it a visual just now, 2 coils on the port have been replaced with new.
The rest I believe are original.
I tested the coils from pimary to secondary, and got these #'s.
Port
245,245,239 and stb, 247,247,245

I started her on the muffs, after settling it idles at 700, but has a split second hiccup drops and returns to 700.

Thank you btw.

[Bassalive]

I checked the wires (sierra 18-5231-1), and bottom cylinder port side was extremely low compared to the rest.
It was giving me 377 on 2k ohms scale, and the rest ranged from 1000 to 1400?

[Bassalive]

Try pushing the choke/enricher next time it does it and see if it runs better. If so, fuel issue. If not, electrical/ignition.

I was thinking last evening before I begin to address this issue the first thing needed is a Max Rules VRO conversion pump you told me to install last season, but after checking the price I didn't.
The facet electric pump the previous owner had installed does work, but....

I sent an email to Master Tech earlier, and as soon as I get their phone# I'm getting one shipped asap.

I did bench test the coils, and they are in spec. I did note that 2 have been replaced with new ones.
I also tested the wires, and there was one, btm cylinder port side was giving a odd reading so I replaced it.

Earlier this Spring I replaced the ignition switch with a new OMC one I stumbled across.
Now the key switch when pushed instantly engages the primer solenoid which I rebuilt as well, and it fires right up no issues.

I have a gut feeling that when the Max Rules pump arrives it will let my XP come back to the party.

Thank you, I'll get back to ya with results.

[bighare]

When was the last time you treated this crossflow engine to a dose of engine tuner?

[Bassalive]

When was the last time you treated this crossflow engine to a dose of engine tuner?

Well I used a little sea foam mixed in a small jug for Spring start up, but that was about it.

[bighare]

I predict it’s time to run a full and overnight dose of Evinrude engine tuner to decarb/loosen the piston rings and piston domes. Get the can that has the injector hose and inject thru the Schroeder valve on the primer solenoid.
I know nothing about the quality of the sea foam brand.

[omcforever]

I predict it’s time to run a full and overnight dose of Evinrude engine tuner to decarb/loosen the piston rings and piston domes. Get the can that has the injector hose and inject thru the Schroeder valve on the primer solenoid.
I know nothing about the quality of the sea foam brand.

Tried seafoam once,,wasnt impressed.
They will carbon/coke up especially if lugged or propped-setup to never see proper operating range or years of cheap dino oil...I set mine up to turn 5500-5800.

[Bassalive]

Tried seafoam once,,wasnt impressed.
They will carbon/coke up especially if lugged or propped-setup to never see proper operating range or years of cheap dino oil...I set mine up to turn 5500-5800.

Evinrude engine tuner eh? I'll will need to make a road trip this week to the boat shop. I live in a fairly remote Lake community limited to 1 country store.
I always say, I'm not in the middle of nowhere, but the road sign is within sight....lol
It floored me to come across Sea Foam actually...lol

While I'm there at the shop what other essentials I should have on hand?
I'm friends with the fellas at the parts warehouse. They part out older motors, and I can still find parts for the GT-XP'S.
I ask that because I'll get down there, and see a Shiny Bass Boat, my mind will go blank, and I'll owe the bank 50k.....lol