Heating Johnson

[Hoserpoppasmurf]

1991 16" Vanguard fiberglass open bow run about with 1991 Johnson 115 Need confirmation, bought this rig 4 yrs ago, health dictated it into storage. It's out now and got it started, hi temp alarm went off. Odd thing tattle tale was flowing well when cold but dried up to spurts as it warmed up. Am I looking too much for trouble than just doing the water pump kit, or should I dig further for something odd. I can't imagine what would slow the flow. As well, I already have a temp gauge and want to install the electric unit. Where is best place to install temp sensor. Any help is appreciated.

 

[jimmbo]

The Impeller should be changed, as it is at least 4 yrs old. If you find pieces of the Impeller missing, there is a chance that some pieces went up the Water Pipe, reducing flow.
There should have been instructions with the Temp Gauge as to where to mount the Temp Sensor.

 

[Hoserpoppasmurf]

Thanks, temp gauge has been sitting on my shelf for 15 yr. lol. It is electric Faria brand, all you get is the box with little wiring diagram, sender, and dash gauge. Currently straining my soup trying to get shifter mechanism loose to drop bottom end. Fortunately marine shop had an actual OMC made in USA water pump kit.

 

[Hoserpoppasmurf]

Just caught another video, the guy says OMC sent out an advisory that the tell tale should be moved from the bottom to the top of the water jacket. Potential problems of air lock and over heat alarms. Anyone heard anything about this. It sounds reasonable to vent air from the highest place that you have water in the engine-anyone???

 

[racerone]

That advisory was for the 56 cube 3 cylinder motors !!----It does not apply to the V_4 models !

 

[Hoserpoppasmurf]

Thank you. I looked at a few how to videos online to figure out how to drop the gear case. Ofcourse as it turns out they ALL did not apply to my engine. So after removing starter, air case in front of carbs, I discover it is so simple to disengage the shifter rod that I figure I deserve the bad karma of having to put that mess back together before proceeding. Actual protocol is from starboard side of engine, there is a clear access to slip pin, easily removed with needle nose, push the slide to the port and shift lever is disengaged, allowing gear case to drop clear (into my waiting hands). Opened pump and didn't find anything dramatic except the impeller was as hard as a frozen hockey puck. Clean it up and put it all back together tomorrow. Then test fire it again.
Another question, I sucked all the old fuel from the built in gas tank. Currently running from a gas can with some synthetic marine oil mixed in. I will need to refill the onboard tank. Our Petrocan gas stations offer 94 octane gas. Any words of wisdom of aye or nay on this.

 

[saltchuckmatt]

Thank you. I looked at a few how to videos online to figure out how to drop the gear case. Ofcourse as it turns out they ALL did not apply to my engine. So after removing starter, air case in front of carbs, I discover it is so simple to disengage the shifter rod that I figure I deserve the bad karma of having to put that mess back together before proceeding. Actual protocol is from starboard side of engine, there is a clear access to slip pin, easily removed with needle nose, push the slide to the port and shift lever is disengaged, allowing gear case to drop clear (into my waiting hands). Opened pump and didn't find anything dramatic except the impeller was as hard as a frozen hockey puck. Clean it up and put it all back together tomorrow. Then test fire it again.
Another question, I sucked all the old fuel from the built in gas tank. Currently running from a gas can with some synthetic marine oil mixed in. I will need to refill the onboard tank. Our Petrocan gas stations offer 94 octane gas. Any words of wisdom of aye or nay on this.

I hope you didn't put the frozen hockey puck back in...that wouldn't make any sense

These outboards do not need high octane gas just no ethanol. You can Google non-ethanol fuel near you.

 

[ct1762@gmail.com]

well i contend "high octane" to a point can only help high thermal loads on a heavy crossflow piston, but also agree they can run just fine on 89 given the timing isnt over 24 degrees or so. the thermostats and poppet valves MUST be fit for service one these, as well as a new impeller and thorough carb clean which means all jets and idle air orifices cleaned to satisfaction.

 

[Hoserpoppasmurf]

Man alive, I can't remember working that hard to do such a little job. Finally got it apart, wrestled the new impeller in as per instructions, leg slipped up into place- and THEN- 4hours trying to get that @*$# shift rod back into place and the stupid pins that holds it together once in. That little spring pin took over 2 hrs of holding the bellcrank and shift rod in position, and finally pushing that pin home. It was 30C,(86F) which for around here is hot. It's done and tomorrow is trial day. Thanks all.

 

[Hoserpoppasmurf]

Hooked up hose and got a big dose of disappointment. Tel tale is not spurting enough water to indicate circulation. I double checked the impeller install and it is correct, the rest of the pump is near fool proof. Looking back at statement of PO, he said VRO was working fine but it was overheating. It was obvious when getting into pump others had been there before me. I now have to look else where for poor circulation, and invest in surface temp gauge. As this is a cross flow the thermostat is down on the bottom near inaccessible because of the high lip of housing. I'm debating whether to try taking it apart or try a chemical treatment on this 31 year old engine. I was thinking of perhaps some automotive type solution (mild acid) to see if I can get circulation back. Upon close look see, it is also apparent the port head has been off at some time-done by others before me. Any suggestions, this engine runs so very well, excepting it over heats and causes the high temp alarm to start screaming.

 

[racerone]

The tell tale is an indicator for the water pump.-----It does NOT indicate good circulation / proper cooling of this motor.----Post the compression test numbers here.----These motors are famous for broken piston rings.------Then some can offer further tips on what to check.-----Like water diverters / guides inside the water jackets.

 

[Hoserpoppasmurf]

Well, why shouldn't I fire the parts cannon? Bought new Sierra thermostat kit, upon cutting out the outer case and removing it all- I didn't find the dirty grungy mess I was hoping for. From what I can see there is only slight build up- what one would expect from a lightly used 31 year old engine. Started cylinder compression test on starboard bank, upper 90 lower 87 psi, then new battery went dead. Will finish test on port side tomorrow. My thoughts are also, is it possible head gasket pressurizing the cooling system and causing my overheat situation. The engine starts and runs so very well other than over heating. Anybody have any more insight to offer??

 

[saltchuckmatt]

Well, why shouldn't I fire the parts cannon? Bought new Sierra thermostat kit, upon cutting out the outer case and removing it all- I didn't find the dirty grungy mess I was hoping for. From what I can see there is only slight build up- what one would expect from a lightly used 31 year old engine. Started cylinder compression test on starboard bank, upper 90 lower 87 psi, then new battery went dead. Will finish test on port side tomorrow. My thoughts are also, is it possible head gasket pressurizing the cooling system and causing my overheat situation. The engine starts and runs so very well other than over heating. Anybody have any more insight to offer??

Your new battery went dead on two cylinder compression tests? That's odd.

 

[racerone]

Compression should be around 120 PSI

 

[Hoserpoppasmurf]

Can't find an authoritative spec as to what compression should be. Found one said on old 2 strokes 90 psi, other said 110 to 130-but didn't qualify whether old or new. Another said must take into consideration elevation, I'm at about 2650 feet. Don't know about battery, has sat for 4 months and didn't loose but .5 volts, it's charging overnight and we attack again tomorrow.

 

[saltchuckmatt]

Can't find an authoritative spec as to what compression should be. Found one said on old 2 strokes 90 psi, other said 110 to 130-but didn't qualify whether old or new. Another said must take into consideration elevation, I'm at about 2650 feet. Don't know about battery, has sat for 4 months and didn't loose but .5 volts, it's charging overnight and we attack again tomorrow.

When you pulled that thing from mothballs I hope you put some oil in the spark plug holes and hand spun it for awhile. You still can by the way.
As you continue to demoth it most likely the compression will come up.

 

[racerone]

Good luck with this motor.

 

[Hoserpoppasmurf]

Thought I would finish up by reporting the final repairs (successful). I finally gave up and pulled the rig an hour away to a marine mechanic that I trust. He had it 5 days (including weekend). He found I had installed impeller correctly, my guess for thermostat replacement was partially correct. He also found the engine was loaded with caked in silt, including the tell tale being partially blocked. He flushed it clean and no overheating. Also found the float for the VRO is some how hanging up and also creating alarm. He recommends removing VRO on this 30 year engine for next year. Stated engine runs very well and appears strong.

 

[ct1762@gmail.com]

Thought I would finish up by reporting the final repairs (successful). I finally gave up and pulled the rig an hour away to a marine mechanic that I trust. He had it 5 days (including weekend). He found I had installed impeller correctly, my guess for thermostat replacement was partially correct. He also found the engine was loaded with caked in silt, including the tell tale being partially blocked. He flushed it clean and no overheating. Also found the float for the VRO is some how hanging up and also creating alarm. He recommends removing VRO on this 30 year engine for next year. Stated engine runs very well and appears strong.

what "VRO float" is he talking about? barring a bad temp sensor, if the alarm is going off or was and he disconnected it, id be making 100% sure its not overheating. if you pull the water hose going to one of the heads off, a huge rush of water should come out, and cool the head immediately. meaning the t stats are clogged or stuck, or the diverter valves are leaking.

 

[racerone]

???----And what are the " diverter valves " and what do these diverters actually do ?