# 92 V4 120 hp Johnson why is she overheating?



## Gator McClusky (Sep 19, 2012)

This one I started on a few weeks ago and took a break! 

1) Bought her without any knowledge if it would run. Never checked compression until I got her home. Checked it the wrong way, left all plugs in while checking all four cylinders individualy. They were all within 2 to 5 pounds of each other checking that way. I need to check without any plugs in (soon).
2) picked up a 3 gallon can and new ball and line, mixed 50:1, removed 18 gallon aluminum tank to be cleaned and replaced, hooked new fuel cell to motor, picked up a new marine starter battery and hooked it up.
3) could not get her to start, tested for spark and had nothing on 3 of the 4 cylinders. Researched and read, got familiar with power pack, coils, trigger and plugs. 
4)decided to replace the plugs first and did so, all cylinders firing now with pop!
5) She will not start. Read more...get ohm meter and check the coils and power pack- learn about the quick start feature-
4) Getting pretty pissed at this point and cant figure out why she won't crank with spark, fuel and air. Go to the console where my 11 year old is patiently operating the key switch, I ask if I can try and he obliges- I push the toggle switch up and turn the key! YES! she sounds awesome!
5) I see no water streaming from the hole so I kill it.
6) Replace impeller by myself after a little reading and watching a little youtube. (I tell about that later!)
7) Fire her off and she starts peeing after a few seconds. The buzzer sounds and start feeling around on the heads. The port side is considerably warmer- no hotter.

I have replaced the stats, removed the stats and ran for short time to flush the ports or try tobut she still got hot.

Put the new stats back in and she continues to heat up on the port side.
I have a gasket to remove the head to check for damage in the cylinder but would like some other opinions besides what I have read. What else should I do. I may be missing a detail or two but thats where I am right now. 

I love this stuff!


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## Talons (Sep 19, 2012)

Hmm... Let's see.

Overheating is caused by lack of cooling or something causing more heat than the cooling system is capable of sapping off. (Obvious, I know).

1) She runs. That's a GREAT start! You have done fantastic so far.
2) She pisses water. That is also good news. We will get back to that in a minute.
3) New thermostats? That is what you meant by 'stats', right?
4) The only thing you have not mentioned anything about is EXHAUST... How does that look? Does it look like enough? Too little? Where are you running the engine? In a tub or with muffs?

Alright, let's start asking more questions, maybe something will ring a bell.

When the alarm goes off, is on from the moment the engine starts up or does it come on after the she 'overheats'?
Is it really overheated or is it just 'warm'?
How is that piss stream? Hard and even and 'full' or is it trickling?
Are the thermostats you put in the CORRECT temperature according to the manufacturer? If you go over or under, that can cause overheating issues. Especially on Johnsons. I don't know why, but they are tempermental to that. Great engines, when in manufacturer's specs, but outside of those and she has some 'issues'.
So, while I am not there, I can ask some questions to 'help' you jog your own memory.

Oh yeah, I had a 33 Electric Start Evinrude years ago and I could NEVER run it with muffs, it would overheat. I had to take it to the lake to run it clear of salt water.

Please know that I am only trying to help.

Talons


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## Talons (Sep 19, 2012)

Gator McClusky said:


> This one I started on a few weeks ago and took a break!
> 7) Fire her off and she starts peeing after a few seconds. The buzzer sounds and start feeling around on the heads. The port side is considerably warmer- no hotter.


If you are saying that after a few seconds the buzzer goes off, you have either; Clogged port side cooling tube; broken port side cooling gasket; hole over there you haven't seen yet; bad buzzer.

Talons


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## Gator McClusky (Sep 20, 2012)

Talons said:


> Gator McClusky said:
> 
> 
> > This one I started on a few weeks ago and took a break!
> ...



Yes, stat is thermostat and yes they are manufacturer spec'd. When I removed the original stats I found large black ants in the stats little ports. i'm wondered about those and thats when I removed the stats and ran without them for a few minutes.
I have read about the cooling passages getting clogged by salt water. However, I really don't think its seen a lot of salt water but not for sure. Should I remove them and leave the plates off and see what the water flow looks like on both sides? Is there a diagram on the passages or a way to clean them?
Now, the exhaust. I replaced the impeller and it got dark on me. Ran the motor and port side getting so hot you cant touch unlike the other head that I can keep my hand on. The next day I found the exhaust gasket on the ground and did not see it fall out in the low light condition. I'm sure I have to get that back in there before I go any further. Would the missing gasket cause it to overheat on the one side? 
And yes the alarm sounds after she runs a few minutes.
Running it on the muffs. 

What do you mean by a hole I havent' seen yet? Exhaust hole? (lol)

That was a rookie move with the gasket but I hope we/I learn something from it! I couldn't believe it when I spotted that gasket under the foot. Especially since I noticed a different sound in the exhaust that night. Thats when I took a little break and worked on something else for a week or so. Thats when I found this site. Don't beat me up to bad with that.
I have thick skin and will welcome an education! thank you.


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## Pappy (Sep 20, 2012)

Make sure you have a good volume and pressure supply to the gearcase to cool the engine on a hose. 
Second. Remove the thermostat assys. and covers and leave them off.
Start the engine and observe water flow. 
Does the water flow look uniform on both the port and stbd. side? Is it overflowing and running down the cylinder heads on both sides or just one?
Are you hearing a hot horn or just guessing that side is running hot? 
At around 135F you should be able to hold your hand on the top of the cylinder head for no more than a few seconds. Both cylinder heads should be gettng to this temperature on the thermostats. If you can hold your hand on the port head for longer then it is not warming up.


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## Gator McClusky (Sep 25, 2012)

Thanks Pappy! I should be able to get on that tonight. I sure hope I have blockage that I can just remove somehow. I really like this rig and I hope it winds up being worth it.

I will post back later tonight and let you know what I find.


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## Pappy (Sep 25, 2012)

Remember - Just run it with nothing there but a large hole on either side that water can run out of. The thermostat assemblies should be completely removed as well as leaving the covers off the cylinder heads for the "test" 
Run it long enough to determine if both sides are flowing about equal. 
Test done!

By the way....I have no clue what a previous poster was attempting to tell you when he mentioned different temperature thermostats ...... there is only one for that engine, period. Also no "tubes" going to each side and the only gaskets on that engine are for the regulator rectifier up on top (which cannot block flow) and the cylinder heads. Your test will determine flow through the cylinder heads. No exhaust gaskets or intake by-pass cover gaskets. 
Also disregard looking at the exhaust. The exhaust port up on the mid-section runs dry.


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## Gator McClusky (Sep 26, 2012)

Pappy said:


> Remember - Just run it with nothing there but a large hole on either side that water can run out of. The thermostat assemblies should be completely removed as well as leaving the covers off the cylinder heads for the "test"
> Run it long enough to determine if both sides are flowing about equal.
> Test done!
> 
> ...



Tried to start her and now the carbs are acting up. Sneezing, Won't stay running without throttle. Took the foot off (didnt sound right, kinda like a car with no muffler) and found burnt oil in the exhaust tube. (?)
In short, I hooked the hose up to the water tube and turned the water on. I have full flow in both ports. Actually, I had better flow on the port side. I put my finger in either port and the flow was the same on both sides. Water was coming from the p hole as well. 
Should I Plug the starboard side with my finger again and see if the p hole runs dry? could it be plugged from the thermostats to the p hole on that one side?
I tried to do it with it running but I could not keep her running and get back there to see the water flow. I know the pump is pumping water. I just wonder if I should try using a barrel or take it to the river and try her out at the boat launch just to see the difference from hose to submerging the foot. I wonder if thats my issue or would it heat both sides evenly?


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## Pappy (Sep 26, 2012)

If it was coming out on both sides fairly equal you are probably good to go as far as blockages go. 
The thermostats cannot block flow to the overboard indicator. That indicator line is just a verification that the pump is working. 
There are muffs on the market that will not grip the gearcase tight enough to feed the water pump. You may have a set. they are plastic instead of the heavy metal rod shaped into a Vee. Some will some wont. 
Another way to check your muffs is to remove the plastic screens covering the water pick ups on the gearcase..... if you have the ones with two screws. Run it on muffs without those and see if the pump will develop sufficient pressure and volume. Indicator line should flow if your hose will feed enough.
The unburned fuel/oil in the exhaust is normal while running on a hose. Disregard it. 
Put everything back together and take to the ramp and run it if the above doesnt work. Place your hands on each cylinder head after a couple minutes. 
Read the above posts on what to feel around 135F. 
I Will be gone through the weekend and early next week ..................


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## Gator McClusky (Sep 29, 2012)

Thinking back when I rebuilt the water pump using the kit with the new housing, I read where some models require the water tube grommet. The kit did not have this grommet so what else could I do? The lady at the parts place said mine did not need the grommet. I measured the diameter of the tube and it is 1/2" ID copper tubing. Can you tell me if the water tube grommet should be on my 1992 120 hp V4 Johnson? The model for the motor is VJ120TLEND. I hope this grommet is supposed to be in there. I hope this solves my issue.


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## Pappy (Oct 3, 2012)

Absolutely you need the grommet if you are talking about the one that fits into the plastic housing and seals the water tube.


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## Gator McClusky (Oct 3, 2012)

Took apart and checked, the grommet that goes in the housing under the black spout that has 2 stainless screws that hold the spout to the housing is in there. I was wondering if there is another that goes on the outer portion of the spout which makes the 1/2" copper tighten to the wall of the spout?
I am thinking not at this point and will hopefully get it to the boat landing tomorrow to try her out submerged, if that does not do it I'm afraid its off to the mechanic. Unless you can tell me something different?


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## Pappy (Oct 4, 2012)

Let us know. 
If the engine overheats you can isolate which side is doing it by disconnection of the tan leads on one cylinder head at a time while the horn is sounding. The horn will quit sounding when the tan lead no longer has a ground path. Cylinder head temp can then be verified by the use of a digital temp gun if you have access to one. The temp sender can be verified by checking the head temp around the pocket where the sender is installed or placed in heated oil or water. Oil is faster to heat up. 
Am thinking you should be fine at this point. Hope so.


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## Gator McClusky (Oct 4, 2012)

Pappy said:


> Let us know.
> If the engine overheats you can isolate which side is doing it by disconnection of the tan leads on one cylinder head at a time while the horn is sounding. The horn will quit sounding when the tan lead no longer has a ground path. Cylinder head temp can then be verified by the use of a digital temp gun if you have access to one. The temp sender can be verified by checking the head temp around the pocket where the sender is installed or placed in heated oil or water. Oil is faster to heat up.
> Am thinking you should be fine at this point. Hope so.



Well, she is still running hot. Large trash can full of water. It seems to take a little longer but the alarm still sounds and the port side is considerably hotter than the strbd side. The laser gun battery went out on me as I was trying to get a temp reading. Will do it again tomorrow with fresh batteries. I will also unplug the tan ground wire on port side just to be sure. 


Thanks Pappy


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## Gator McClusky (Oct 5, 2012)

Pulled the power head, carbs rebuilt, backed into the river. 

She aint running hotter on the port side no more. Found a plastic plug which looks like the kind they use during painting process at factory. Didnt see it on the engine but it was the only thing laying around on the concrete and the floor was clean when we started. 

Looks like it was never running hot on the port side (160*f), just a lot hotter than the strbd side (121*f). We took it to the river before pulling the head as well. The alarm was the VRO alarm. The hose was disconnected but the alarm wasnt. It was sneezing, skipping and cutting out. It wasnt idleing well and when you ran it hard in gear it wasnt firing on all Thats when we decided to pull the head and rebuild carbs.

Be back in a few


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## Pappy (Oct 5, 2012)

You pulled the power head or the cylinder head??
When you get it back together we will go through some simple sync and link procedures that should help with the low speed running quality.


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## Gator McClusky (Oct 6, 2012)

Pappy said:


> You pulled the power head or the cylinder head??
> When you get it back together we will go through some simple sync and link procedures that should help with the low speed running quality.



First we pulled the cylinder head and it was clean as a whistle. Then we pulled the power head, cob webs and dirt daubers. It's already back together. The shop I took it to jumped right on it, turns out he was a good friend of my dad (passed away two years ago). So he went thru it and let me help and I was very happy with the results. We never saw the plug in the port but we blew it out real good with compressed air and found the plug on the concrete with black paint on it and a little whole pierced in the plug. We are only speculating that it was factory and this has been an ongoing issue with this motor which explains why the insides and outside of the motor are so clean. It appears the previous owners never broke a bolt on the motor. The port head was reaching 160* to 165* before the strbd head was was reaching 120* which made me think it was running hot on one side. I saw where the alrm should sound around 197 or something like that?
Anyway, the power pack is acting up. You can tap on the power pack and the motor will change idle. It was jumping all around. He rebuilt the carbs and wants to complete it today or Monday. Taking it to the lake when I pick it up to see what its all about. 

I asked him what he thought the motor was worth now that all the bugs are out and his response was a little more than i paid for the whole rig. It was a gamble and it really paid off so far. 

Well, off to dove shoot with my 11 year old son. 

I would still like to learn to sync and linc though.

thanks


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## Gator McClusky (Oct 8, 2012)

TO nasty out to run it today but I did get it back and he said she is all good. Taking it out to the lake tomorrow with a few guys from work.


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## Gator McClusky (Oct 10, 2012)

New Power Pack, 4 carbs rebuilt, new choke, release the blockage on the port side cooling passage and she feels like she is close to 55 mph on the water. This thing really rolls out. I am very pleased with the performance and handling. She sucked down 3 gallons in what felt like 15 minutes. 

Taking the little man and his friend out Saturday to play around then Santee with the guys from work the following weekend. After that its time to start work on the rig thru the winter.

Going to pick up a stereo from Academy Sports today to install and may find a trolling motor for her before the Santee trip. 

I really need to get the phone replaced so I can use it to share this thing with you guys. It's awesome!


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