Johnson 130 Over heating

[jwall116]

Was out having a great time adventuring some new creeks with the boat and got the over heat alarm. Earlier in the day I has gotten into some mud, thinking i had some mud stuck I let the engine cool off and ran it at a low cruise back. When the alarm came back on I backed off the power and the alarm went away. We would troll for 10 minutes, then back to 4000 rpm for about 5 minutes before the alarm came back. When I pulled the cowl off at the dock, one side was warm and the other side significantly cooler.

Got home, pulled the t-stats. No debree in the housings. Tested the t-stats on the stove, one opened and one did not. Found the problem !

Now for my question..... There is a housing that is cracked. Didn't seem to want to come out so I didn't force it. How do I remove it and does it need to be replaced?

iboats is missing the part on their list WTH!!????

http://www.iboats.com/Cylinder-Crankcase/dm/cart_id.126843695--session_id.204252480--view_id.1542176

# 38

 

[jwall116]

Update. Got that part out and it will need to be replaced.

Now whats up with it missing from the iboats list?

 

[Faztbullet]

OEM part# 0336178

 

[jwall116]

Thank you !

iboats doesn't carry it :grumpy: Ordered through my local dealer.

Does the over heat alarm come on early enough to prevent damage ? When i touched the engine it was warm but not boiling hot. I could touch all cylinders with my bare hands. Tops of the heads were probably 130 degrees.

 

[w2much]

Yes the alarm does come on before damage if properly operating. When the engine starts knocking is the other alarm that one comes on after the damage. That alarm is mental, it says BOAT (break out another thousand) If you only went to 130, no worries. Good job getting it done.. Harbor freight has infrared thermometers for about 20 bucks. I keep one in my boat bag all the time. When trailering I check my wheel bearing heat and then have it with me when on the boat should I or someone else need it.

 

[jwall116]

I have an infared thermometer.. at the house. I pulled the cowling while I was out boating and could still touch both cylinders.One side was warmer than the other by a solid 25 degrees.

Pulled the plugs, the plugs on the hot side had a dark band on one side of them and no left over oil on the insulator. The cold side had light oil coating as usual with this engine. 50:1 premix with factory champion plugs per the book!

Parts will be here tomorrow and back on the water soon enough. Temps are getting into the 60's now in Houston. Wont stop me. We boat year round here.

 

[sutor623]

Hope you got her back up and running. The overheat alarm on those motors cuts on in the 207 degree mark if memory serves me right. I doubt that motor only hit 130 degrees. That's cooler than the thermostat opening point (143 degrees). Either your temp switch is acting up or that motor hit over 200 degrees. If you had burned off all the residual oil on one side, you have answered your own question. Next thing that I would do is a compression test just to make sure you didnt score anything or warp a cylinder head.

 

[oldboat1]

Mud and sand can do a job on impellers -- would be good to check.

 

[jwall116]

I had a stuck thermostat. Replaced both sides and tested in drive way for 20 minutes using a temp gun on both cylinders.I have a 60 gallon flush bucket that I use for flushing, no muffs. They stayed within 10 degrees of each other and got up to 140 degree's.

Ran the boat Wide the hell open most of the day yesterday, no over heat alarm.
Got full RPM as usual. 5600 into the wind (gusting 20mph!) and 5800 with the wind. With 4 people in the boat and half tanks.