Logo
FULL SITE MENU

2004 Johnson 90 hp 4 stroke got hot.

E

eager25

New member
Over the weekend with the boat full I ran into some sand , overheat alarm went off and shut down the engine . After getting pulled back the dock I took out the water flush plug to get the sand out and saw that it was almost melted. After flushing the motor it seems to be peeing okay. Now anything above idle seems to make my check engine light come on and my volt gauge is pushing over 16 any ideas? Idles smooth and seems to run the same as before.
 
Gee....I just can't imagine it getting so hot that it melted the flush plug.
That is way down on the oil pan. If it got so hot down there, what did it do to the head?
You should do a compression check now. It should be in the 200 psi range for all cyls.

Anyway, you have a water cooled rect/reg. It likely fried from the heat/lack of water.

Your tach should be blinking a code at you. It will be a series of flashes of the check engine light,
a code 1-1 is for the reg/rect with the EMM seeing over 16v.

That reg/rect is about 200 bucks.
 
It didn't really melt it, softened it would be better phrasing. Getting a compression tester tonight. Would the reg. cause the check engine light? I read it was fuel related if it came on. The tach is not digital so you must be talking on the engine itself I assume.
 
Yes my post clearly stated that a bad reg/rect will cause the check engine light. It should be flashing at you...1 on, pause, 1 on, longer pause, then the 1-1 pattern again, three times total. Isn't your check engine light internal to the tach? Four lights along the bottom on the tach face?
If not, where is this check engine light? Is it on a small 2" gauge with four lights?
 
By the way, there are about a dozen different faults that will cause a check engine light. And not just fuel related.
Mostly overheat, various sensors, etc.
 
No, probably will not be visible. But worth a look for sure. It doesn't take but a minute or two with no water to destroy the reg/rect.
You will need to go thru the tests, but I am certain you blew it if you are seeing 16v.....
 
Here is an update, I checked the comperssion on Saturday and all cylinders checked out at 211and 212 so that's good. As far as the charging system goes , it still running high on voltage but my check engine light is no longer coming on. My question is, is there a component in the regulator rectifier that I need to replace or the entire unit? Also will it do any further damage or damage anything at all if I run the boat until I get it replaced?
 
Three things....One, the stator might be getting too hot if it is feeding a bad reg/rect, and two, your battery will be charging at a high rate constantly. It will need to have the water checked often.
Third, the EMM might not like the constant high voltage....

I would replace it ASAP, but that is just me, I guess.

The reg/rect is a single sealed unit. You have to replace the whole thing.
 
Follow up question. After changing the rectifier everything seems to be better with the voltage. My question is this, directly after the overheating incident I noticed that the fuel bulb no longer go hard when I squeezed it, and now it's beginning to idle a little rough when its cold. I have changed the fuel bold and was wondering if it could be something as simple as I need new spark plugs?
 
Back
Top