140HP Johnson Looper Alarm mid 80's

[ksound]

Hi Folks, HELP!
There's an Alarm that comes on when I open up to plane out!
If I put it back in nuetral, and idol for a bit, The alarm goes off!

There is a steady stream of luke warm water flowing from the engine...

I can run all day (and have twice) just putt-ing around for hours without a single peep, but as soon as I get bored and want to go faster, the alarm goes off again... sometimes I'll get her planed out for maybe a minute or more before the alarm will come on... but it always comes on, then, as soon as I let her rest a bit the alarm goes off and I can putt around again for as long as I want...

I bought the boat this year, and was able to run at top speed all season and the alarm never came on, the oil injection was bypassed when I got it, so I've been doing the 50:1 premix... she's been running pretty good all season and i've been out a bunch... any ideas?

 

[Walker]

Re: 140HP Johnson Looper Alarm mid 80's

Needs a new water pump. Yours is pumping enough water to cool the motor at lower speeds but high speed creates more heat and needs more water.

 

[ksound]

Re: 140HP Johnson Looper Alarm mid 80's

Thanks, that sounds like it makes sense, the impeller was new at the beginning of the season! but I dont think the water pump assembly has been changed for a while...

 

[Dhadley]

Re: 140HP Johnson Looper Alarm mid 80's

Now you know why it's not a good idea to change just the impeller.

 

[dajohnson53]

Re: 140HP Johnson Looper Alarm mid 80's

could also be a fuel restriction alarm.

 

[Walker]

Re: 140HP Johnson Looper Alarm mid 80's

could also be a fuel restriction alarm.

That alarm should have been disabled when they dis-abled the oil side of the VROthe VRO

 

[dajohnson53]

Re: 140HP Johnson Looper Alarm mid 80's

That alarm should have been disabled when they dis-abled the oil side of the VROthe VRO

May be true. However, my old engine which had the VRO disabled, still gave me a fuel restriction alarm if I didn't have the T valve completely open. May have been poor rigging, but it was there.

Is it SOP to also disable the fuel restriction alarm? Maybe I'm wrong, but I thought that when VRO was disabled the SOP was to disable the low oil and no oil alarms.

 

[Walker]

Re: 140HP Johnson Looper Alarm mid 80's

Its all in one wiring harness and the usual way to disable the oil alarm from the VRO is to just unplug the harness. The oil tank has a separate harness.

 

[dajohnson53]

Re: 140HP Johnson Looper Alarm mid 80's

Its all in one wiring harness and the usual way to disable the oil alarm from the VRO is to just unplug the harness. The oil tank has a separate harness.

Makes me wonder now what alarm I was getting. Happened only a couple of times and both times fairly soon after starting, well before I got into the high RPMs. Both time alarm went away immediately when I opened the valve. I wonder if it was a high temp alarm (??because of lean fuel??), but it sure wasn't acting like one.

I don't have that engine any more, so will never know!

Sorry if I mislead OP.

 

[Dhadley]

Re: 140HP Johnson Looper Alarm mid 80's

That motor doesn't have a low fuel pressure alarm. Beats me why not, it's an excellent tool. On motors that do have it, you can disable the oil injection alarm without affecting the fuel pressure alarm.

 

[dajohnson53]

Re: 140HP Johnson Looper Alarm mid 80's

That motor doesn't have a low fuel pressure alarm. Beats me why not, it's an excellent tool. On motors that do have it, you can disable the oil injection alarm without affecting the fuel pressure alarm.

Dhadley - is it possible to have a low fuel pressure alarm on an older engine if it's been rebuilt or parts have been replaced?

The reason I ask is that the engine I was describing above was from the early 80s, pre-VRO, but during the remanufacture process, it had a newer vintage VRO fuel pump (with oil side disconnected - go figure). I know it was a VRO pump because I had a problem with air leaking and traced it to a faulty cap on the oil inlet. But I did have what I thought was a fuel pressure alarm as described above.

Sorry if this is irrelevant for OP's question, but I'm still wondering if there is some small chance he might be chasing a fuel supply issue. If no chance, I'll keep my mouth shut ;-)

 

[Dhadley]

Re: 140HP Johnson Looper Alarm mid 80's

If someone has put a low fuel pressure alarm on it it'll have a vacuume switch tied into the fuel line between the front of the motor (where the line comes in) and the fuel pump.

 

[ksound]

Re: 140HP Johnson Looper Alarm mid 80's

I run the boat in saltwater and never flushed the engine after use. The last year or so I have been flushing the engine, I also use the salt away flush system, I have a stronger stream of water flowing now and the alarm never comes on.

 

[clanton]

Re: 140HP Johnson Looper Alarm mid 80's

IF you disconnected the VRO harness and the oil tank sensor. The only sensors left are the two overheat sensors. Disconnect both overheat sensors, if alarm stops, replace alarm horn.

 

[ksound]

Re: 140HP Johnson Looper Alarm mid 80's

Nice Thanks