Thermostats in outboards ?

[Sean Youngblood]

I have a 1990 Johnson 90Hp.My last trip out last year my temp warning signal went off.Today I checked my impeller it seemed fine but replaced anyway.I put it on the muffs it started right up and seemed fine had a decent pee stream after it warmed up.After about 5 minutes or so my temp alarm went off again.I then waited 10 min.or so for it to cool and the alarm went off so I figure my alarm is working properly.So now I suspect the thermostats.They seamed a little caked up but not bad.I put them in a pan of water on the stove to see if I could see them open like a car thermostat. There didn't seem to be any movement.Should I be able to see them open and close as I heat them up and cool down?The inside of the of the water ports around the thermostat housing seemed pretty caked up with white build up from being in salt water a few times(by me and the previous owner}Is there any thing to safely flush it out with? I plan on putting in new stats in just want any feedback on anything else to check or to do while I am in there before I put it back together.Access isn't real easy. Thanks     . 

[G-Daddy]

_{I have a 1992 Johnson 100hp - same powerhead.  Now it is used almost exclusively in saltwater, but I got to the point where I change the thermostats every spring as routine maintenance.  Because I change them so often I made a couple of mods to the lower cowl to facilitate.  I made a couple of holes so I can get a ratchet with an extension on the outer housing bolts and plug the holes when the job is done with a couple of fender washers and big rubber grommets.  This kit will have everything you need.  http://www.iboats.com/mall/partfinder/?cart_id=986054927&gd_grid_id=1723&gd_poid=111072&gd_row=39&session_id=846254951} 

[Sean Youngblood]

Thanks G=Daddy chase any Stripers yet ? I am getting the itch.

[jimski2]

Could the alarm be for your oil level in the tank? Usually there is a temperature sensitive dab of paint that changes color when the engine overheats, check it.

[finsntins]

run your hand through the stream when the alarm goes off,if it is actually running hot you will know,if the water isnt "steaming"then you may have a bad sensor.also,before you get deeper into the motor,if you have easy access to a ramp,i would try running it on the trailer in the water,sometimes they just dont get enough on the ears especially at idle.

[Chas0218]

When I first put my 150 on my boat it would give me an alarm.  Mine was caused by a fuel line that would kink once it was trimmed up and slightly turning to the right.

[Sean Youngblood]

Could the alarm be for your oil level in the tank? Usually there is a temperature sensitive dab of paint that changes color when the engine overheats, check it.

Oil alarm is a intermittent beep mine is continuous.

 

run your hand through the stream when the alarm goes off,if it is actually running hot you will know,if the water isnt "steaming"then you may have a bad sensor.also,before you get deeper into the motor,if you have easy access to a ramp,i would try running it on the trailer in the water,sometimes they just dont get enough on the ears especially at idle.

I put my hands in the stream didn't feel hot at all.Never had a problem running on the muffs but you could be right.I also unplugged the tan wire on the temp censer  

 and the alarm went off.Guess I will put new stats kit in it and hope for the best.Hopefully the temp censer isn't bad I really don't want to pull the head off to replace it right now just want to fish.Thanks for the reply's 

[Chas0218]

My oil alarm was continuous.

[L&M]

.

Hopefully the temp censer isn't bad I really don't want to pull the head off to replace it right now just want to fish.

 

No need to pull the head, just the water jacket cover on the head.

[G-Daddy]

No stripers yet - started down the road with the Sportcraft last Friday and broke a wheel bearing and hub/brake assy.  Picking her back up Saturday from the repair shop - no one had parts.  Son is turkey hunting in South Dakota this weekend and it looks like two weeks until we will get to try again.

[Sean Youngblood]

Stopped at 2 marinas this morning nether had my parts.As a last ditch effort I pulled the stats out of a parts motor I picked up a couple of years ago that had a bad cylinder.It seemed to do the trick ran it on the muffs all was good.Hated to put used stats in it there cheap to replace and not so easy to get to.Heading to Conesus for the night shift. 

[G-Daddy]

Good to go is good to go regardless of how you get there.