1993 Johnson 150 60'. Plugs Question.

[Vic.S]

Re: 1993 Johnson 150 60'. Plugs Question.

My IR Gun shows 61 Deg port and 63 Deg stbd

Units? units?
If thats degrees Celsius that sounds fine. If that's degrees Fahrenheit then something wrong .... far too cold.

if its any other temperaure scale (there are several) please specify.

 

[James R]

Re: 1993 Johnson 150 60'. Plugs Question.

Thanks VicS.
Yes that was Celsius or centigrade as we used to call it.
Tried the dealer for the Thermostat open temp but he didn't know.
Thanks also for pressing me to get a temp gun. Neat little bugger.
The correct spark plugs seem to have made a difference in the overheat. Both cylinder banks are now about the same temp.
Will know more after the lake test.
Will advise.

 

[aclmvh]

Re: 1993 Johnson 150 60'. Plugs Question.

Most tstats open in the 135-145F range.

 

[DGartzos]

Re: 1993 Johnson 150 60'. Plugs Question.

Make sure you're not out testing on lake at 61 to 63 degrees Kelvin !!!

 

[nymack66]

Re: 1993 Johnson 150 60'. Plugs Question.

My 87 140 v4 numbers are Port 130 F Starboard 140 F at idle up to 2k rpm, at WOT Port drops down to around 122 and starboard drops to 130
Hopefully that helps

 

[James R]

Re: 1993 Johnson 150 60'. Plugs Question.

So based on the old formula Cx5/9+32=F my motor is right in the range of the Thermostat opening Temp'
Thanks Guys.
Oh by the way I called Kelvin and he said he has nothing to do with this application. This was too scientific for him.

 

[James R]

Re: 1993 Johnson 150 60'. Plugs Question.

Some success with the lake test. Took my new Temp gun along.
Alarm came on, throttle back as before and alarm went off. Checked temps, 145 and 147. Pulled connection to stbd sensor which killed the alarm before but this time the alarm continued. Ran the motor at 3500 No problem except the alarm continued. Brought her up to 5000 and the motor stopped. Temps still ok but spotted the bulb had collapsed. So it looks like a tank or bulb problem. Relieved the bulb and brought her home.
Idles perfectly and runs smoothly. Looks like the correct plugs really helped.
I note that there is a vacuum sensor on the fuel system. Could this be the source of the alarm?

 

[Faztbullet]

Re: 1993 Johnson 150 60'. Plugs Question.

Yep!!

 

[James R]

Re: 1993 Johnson 150 60'. Plugs Question.

Thanks FB. I have replaced the bulb and will switch to another test tank. Using 6 gal tanks to break this motor in on a 16ft Cobia BR. Not using the on-board tank yet. We have rebuilt this boat. Do you have the warning signal format for this motor. Constant warning is usually overheat. Is it the same for the vacuum failure?

 

[James R]

Re: 1993 Johnson 150 60'. Plugs Question.

OK Guys. All is well. To Summarize. The rebuild of the 93 150HP Johnson was a success. The overheat issues appeared to be as a result of the wrong plugs.
The same continuous warning signal was as a result of using a 6gal tank with the standard fittings. Obviously not allowing enough fuel thru and causing the fuel vacuum switch to trip. Now back on the built in tank with a big water trap filter in line all is well. This 16ft Cobia, that we also rebuilt, I expect, will top out in excess 55MPH when I come up on full revs. A little more breaking in yet.
Thanks to all who responded to my calls for help.
This is one dandy Forum.

 

[jonesg]

Re: 1993 Johnson 150 60'. Plugs Question.

150 horses on a 16 footer ...
release the hounds!

 

[James R]

Re: 1993 Johnson 150 60'. Plugs Question.

Will try to post pictures or the finished article. Hope they come thru.