Neutral safety switch maybe.

I've had very similar issues on my 2004 150hp Johnson.

Had very similar issues with an 07 150 ETEC - died like that a couple of times and the third or 4th time we had to jump in and swim the boat the last 1/2 mile to the dock. Turned out to be a defective ECU - apparently it would quit when it got warm but the last time was fatal for it. Replaced the ECU under extended warranty about a month before that went out.

I suspect the powerpack is failing.


You can disconnect the boat harness plugs and jump the starter to eliminate the key switch, kill circuit and boat wiring while the issue is happening.

1997? Is that a FICHT?

If it is, here's something to look at:
The engine computer on a FICHT is raw water cooled. Look at your ECM and if its got fins on it its air cooled, if its got hoses going to it its water cooled.
The passages that cool the ECM get clogged with scale and the ECM gets hot at high RPM's and starts to throw codes and kill the throttle.
Will idle all day but wont let you run around at high RPM's.

Fixed a couple here on the Cape by just taking the ECM off the motor and cleaning out the passageways. Worked every time.

Worth a shot at least.

this is true - the EMM indeed is water cooled,however,when the EMM "cooler" is clogged - the motor will go into limp mode,dropping the RPM to 1,800,alarm will sound too

another point of clogging is in the fuel cell - fuel cell is sea water cooled as well

those problems are related to FICHT motors/DI motors - not sure if this is a FICHT motor

i'm guessing a "gremlin" is an intermittent problem ? the motor shuts down,and refires after sitting a few ?

FYI - The water that comes out of the tell-tale on the small block 2.6L E-TECs (and probably on the later Fichts) is the same water that cools the ECU/EMM and fuel in the Vapor Separator Tank, so if either of those passages gets clogged, you may see a reduction in flow out the tell-tale! Unlike the big block 3.3/3.4L motors which use a low volume/high pressure "pisser stream", the small block 135HO/150/175/200 hp motors use a high volume/low pressure system, so it's very important not to restrict that flow. It's tempting to leave a male quick-disconnect fitting in that port since it's the same one you can use to flush the motor, but make sure the fitting has an inside diameter of AT LEAST 3/8"! I use a brass fitting that's about a 1/2" in diameter which seems to also keep exhaust soot off the cowling. DO NOT use the gray BRP flushing attachment made for the big block motors because it will restrict cooling flow to the EMM and VST!