1980 Chrysler Sea King 15 Overheating/Waterpump Concerns

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Does that motor counts with a side exhaust cover, if so remove it and clean all the internal water passages. If that thermo was found completely salted, crusted, scaled, whatever, imagine what's going on inside the thermo's area. For any motor to cool properly throughout the whole throttle range all water passages must be scrapped clean as when out of the box....

Happy Boating
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
Guess you didnt read the OP posts Sea....
Sam you need to look in the lower unit for a freeze damage crack or area thats diverting water flow from lower unit.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Did you replaced the broken seal seen on post 11 ? have you installed a new thermo ? If all the water passages has not been manually scrapped cleaned to an impeccable condition and keeps overheating or not peeing right that 41 year oldie which has been run in alt water needs to be flushed with removed thermostat with a descaler product to remove internal salt deposits, layers, crusts whatever that's blocking any water passage.

Mentioned your dad and uncle overheated and broke the motor, specify broke the motor ? the motor overheated so badly that warped the cylinder head and had to be reshaved flat at a machine shop ?​

Happy Boating
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
Reading a problem Sea? Owner clearly states this model has no t-stat and pics show no build up. Where you get idea it was ran in saltwater?
Sam....All impellers at low speed are a positive displacement pump, then as RPM increases the blades/vanes the flex inward and it acts as a centrifugal pump. So loss of pressure at higher RPM's would either be air introduced into system from: cracked housing above intake, exhaust leak, turbulence from hull, that crack in copper tube is no good either, as could heat and open up dropping pressure.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Hey FB is the German doctor visiting you, it's the third time being mentioned the motor doesn't count with a t-stat. The powerhead hasn't been teared up showing pics of all related water passages to state the motor shows no build up ? do you count with X Ray Vision to check that out in behalf of the OP ? Does the pic shown on post 2 corresponds to a salt or fresh water scenario ? The issue is no new poster states how old are their motors nor the water environment in which were, are boating at.

Outboard motors are way different animals compared to any krypto green cooled motors in which there's no need to clean periodically any of their cooling water passages. You're a prime example that you give crap about years of use and water used at. Congrats, seems you're the only live example boating with jurassic motors in distilled water..

When having overheating issues, motor not peeing right must tear down the powerhead and visually inspect to impeccable clean all related water passages for the motor to cool properly as was factory designed to work, partial cleaning along time waste improves nothing.. Must start from the lower leg's water intakes going upwards. If the lower vertical narrow water passage located inside the lower leg has reduced its diameter over the years, the impeller will suck less water and if the powerhead has excessive salt layers, crusts, scale already built up issues worse case scenario ever.

Let the OP respond what asked in post 23 and cut your beloved repetitive invasive crap.

Happy Boating
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
I dont need X-ray vision ..just look at OP post #8 and #15 and clearly shows no build up or salt usage. OP cant answer post #23 as motor came from factory with no t-stat. Sea at least have some knowledge of the motors you are dealing with before you post. And by the way I have work on many a salt and brackish water motor.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Recapitulating: The OP doesn't know if his motor is peeing strong, that strong or poorly as can't compare it against a new same motor once peeing out of the box, if having an overheat condition or not, to rule that out must take several temp readings with a precise IR heat gun on a new similar motor at different heated areas soon after the powerhead has been sufficiently warmed up at idle to compare the temp fluctuations between a new motor out of the box and one having or supposedly having overheating issues due to internal crap poorly removal.

The OP has not answered if the water pick up tube's grommet seal has been replaced, if the motor has always been run in salt or fresh water environments as has found calcium layers on the impeller when removed. If the motor is positively found running overheating there's still some nasty built up crap leftovers inside the powerhead, there's more hidden water passages to it that the ones seen at already opened areas.

If you have worked on many salt and blackish water motors you have Olympically bypassed checking the lower leg's vertical water passage condition that sends water under the lower water pump as it's of no importance to you due to being a lazy water passages troubleshooter. If that Sea King were mine that area would be the first to look after and then go from there. Let's see what the OP has to say regarding what posted.

Happy Boating

 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
Sea...As I have and several others have stated..you have no idea what you talking about.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Sea...As I have and several others have stated..you have no idea what you talking about.
What's up, don't like me to ventilate your truths to respond in a childish manner. Keep your opinions to yourself and do not hide behind the opinions of others to beef up your post. The OP was the only one to tell if that information worked or not, at least he took the trouble to visually check it out.

So what I write about doesn't happen in real wet boating world ? That motor is no different than the rest, works and cools on water and if being that old could end in being extremely salted or scaled and achieve overheating issues in which need to troubleshoot, clean repair whatever needs to be done to the whole cooling system, that's lower water intakes/powerhead. An extremely long tiring work Not recommendd for oldie lazy techies....

BTW, I don't care what other idiots and arrogants like you think of my posts, mine are darn technical and with proven pics on the subject I know well due to having being there several times. Send me your address to send a free 55 gal drum of Concentrated Bug Off....

Happy Boating
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
I will send you some glasses as if you look at pics of motor the OP has posted there is NO scale or build up in powerhead. I dont hide behind anything, I tell it as it is with real world technical information, not the stuff you dream up in your head.
 

Samu_el

Cadet
Joined
Jun 18, 2021
Messages
24
Hi guys. I think it might be appropriate for me to add a conclusion to my motor. First off, I didn’t get any notifications that others have replied so I am sorry for overlooking. I would like to thank everyone for their help! It means a lot to know that there are helpful people here. I believed that my outboard head seemed to get really hot when my motor is ran hard in gear stationary or while plowing full throttle on a heavy boat that cannot plane out. It also looked like less water was coming out of the exhaust holes whenever I did this. On plane and idle however the water pumping seemed good. I’m guessing that when the propeller is spinning at a high rpm while the boat is stationary is actually sucking the water out at the bottom exhaust hole so it seems that less water is coming out. The water I poured on the cylinder head in one of my videos was boiling and steaming. I’m guessing also that it was also because I was pouring it near the spark plugs which get hot. I used a heat gun from Amazon and don’t know how accurate it was. I think it was reading 300+ Fahrenheit at the spark plugs. I took the powerhead off, the exhausts, and I’m positive the motor had no blockages in the head. This is a freshwater motor with maybe the occasional visits to brackish water. I replaced the seal on the waterpump housing, replaced the wear plate, replaced the already new impeller thinking that it might have been old stock. It was likely running fine the whole time. It’s been 2 years since I made this post and I’ve been running the motor without visual heating problems. I avoid running the engine too hard on a heavy boat that can’t plane. But I’ve planed my small inflatable boat for 30+ minutes consistently and my 14 ft aluminum around rivers and lakes feeling confident. Only thing I needed to do was clean the carb once. I suppose a new impeller and lower unit oil is due.

-Sam
 
Top