63' 5.5 overheating

tyler_wilson52 · Mar 30, 2013

My motor was overheating after running for a few minutes. Strange thing is it was spitting plenty of water. I did notice that the hotter it got the less water came out. Also, i would kill the engine, let it sit for a minute then restart it and it would be spitting plenty of water again and be cool. Took the thermostat out and same thing.

Anyways, I decided to pull it apart and check the impeller cuz my shade tree mechanic wanted $150 to do it, and I found that the impeller looks like it has recently been changed. Now I'm looking around and seeing that other guys on the internet are saying the fuel oil ratio is 24:1 on this year of motor, I'm running about 45:1. Could this be the reason my motor is overheating? I'm sure it is but before I put my motor back together I would like to know for sure. I ordered an impeller and some gaskets for the power unit anyways since I already have it apart.

raczekp1 · Mar 31, 2013

Re: 63' 5.5 overheating

oreder impeler+ termostat+ water pump sleve.
this motor has waterpump with aluminium housing.
tis housing can worn out, but first put new impeler +slev and termostat

Johnson

Johnson

HighTrim · Mar 31, 2013

Re: 63' 5.5 overheating

Does it have a plastic impeller housing or metal?

'63 is a year in the gray area. You will get plenty of guys telling you to run at 50:1. Im not going to be one of those guys. Run it at 24:1 and enjoy your powerhead for a few more years to come. Todays oils are much improved, and worrying about plug fouling is in the past.

Now, lets wait for those guys

How hot is it getting? If water sizzles when you splash it on the head, or if you cannot hold your finger on the head for a 3 count, she is too hot. There may be a circulation issue. If the impeller is brand new, the old owner may have had an impeller explode, and chunks of the rubber are lodged in the cooling circuit. Run compressed air, or the garden hose, up the water line while the lu is down to the t stat housing, then backflush from the t stat housing to the water line, until it is clear.

tyler_wilson52 · Mar 31, 2013

Re: 63' 5.5 overheating

It is a metal housing. It was getting hot enough where I could only hold my fingers on it for a couple seconds or so before it was just too hot. With it all apart I blew/washed out everything, wasn't really much of anything. I ordered several new parts (impeller, gaskets, sleeve) didnt even think about getting the thermostat while I was ordering the stuff. How can I tell if my old one is bad, or do I even need it? I live in kansas and I was told I dont even really need it here. But I just dont know enough about it.

HighTrim · Mar 31, 2013

Re: 63' 5.5 overheating

You most definately do need it. It controls the min temp, not the max. It will run too cold without, fouling the plugs, building carbon, etc...

You can test it in a pot of water with your wife's thermostat, to see what temp it opens at, if it opens at all.

Did you order the plastic housing with small impeller or the larger impeller?

tyler_wilson52 · Mar 31, 2013

Re: 63' 5.5 overheating

I just ordered the impeller. I dont know if it is larger or not but my guess is it is the same

tyler_wilson52 · Mar 31, 2013

Re: 63' 5.5 overheating

thanks for the test on the thermostat! With our thermometer it was hard to tell but it looked like it was about 115 degrees when it opened

HighTrim · Mar 31, 2013

Re: 63' 5.5 overheating

What part number did you order for the impeller. Just dont want you to get the wrong one. Happens alot.

tyler_wilson52 · Mar 31, 2013

Re: 63' 5.5 overheating

part # 0434424

tyler_wilson52 · Apr 1, 2013

Re: 63' 5.5 overheating

Thanks HighTrim, you have been some good help. So could the fuel oil ratio be causing it too overheat? I don't think I ever got a good answer on that and I have not been able to find anything saying definitively that it could cause the overheating

nwcove · Apr 1, 2013

Re: 63' 5.5 overheating

not enough oil will cause a motor to run hot, and cause severe damage. if you were running at 50:1 , i doubt that would cause it tho. i do agree with hightrim..run it at 24 :1.

raczekp1 · Apr 2, 2013

Re: 63' 5.5 overheating

this water pump housing has smal hole inside, clean this hole and pasage under water tube gromet

tyler_wilson52 · Apr 3, 2013

Re: 63' 5.5 overheating

Thanks yall. I got my parts in so I will be putting it back together this weekend and post my results

jbjennings · Apr 3, 2013

Re: 63' 5.5 overheating

I don't think the 45:1 is the problem as far as temp. Just follow the advice you were given on thermostat, housing, clearing of the water jackets/tubes. Make sure the water tube grommet at the base of the powerhead is not crimped or boogered up. Ditto on the 24:1.
I'd also clean the carb and make sure the high speed non-adjustable jet is spotless, although without the proper tool I wouldn't attempt to remove the orifice plug.
JBJ

tyler_wilson52 · Apr 6, 2013

Re: 63' 5.5 overheating

So got parts replaced and put back together. AND IT'S NOT OVERHEATING!!!!! I replaced the impeller, water tube gromet(although they both looked almost brand new), gasket under impeller housing, powerhead gasket, made sure everything was clean and clear and increased my oil/fuel ratio. Now she still purrs like a kitten but doesnt overheat.

Thanks for the help

63' 5.5 overheating

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