Hotter than normal temps. I just replaced the impeller on the sterndrive, and pulled the circulator pump.

[1985 Century Mustang]

Last week or so I replaced my impeller in the sterndrive and everything was running as usual without the thermostat in. With the suggestions/recommendations on this forum, I put in a new thermostat and it seemed to run fine at 140 degrees, which is normal in what I'm reading.

Today I ran the boat again with the rabbit ears on in my driveway and the temps climbed to 180. I shut off the engine and checked the thermostat, It appeared to be fine, but I removed it anyway to trouble shoot the higher temps. I ran the boat again without the Tstat and the temps went up to 180 degrees again, so there wasn't any difference with the Tstat in or out.

With that I pulled the circulator pump and the blades on the pump seemed to be fine and it spun with no issues. I'm not sure if the circulator pump is bad, or the newly installed impeller is bad, in which I highly doubt.

I then took a garden hose with your basic water pressure and placed it into the Sterndrive inlet hose that comes up off the Sterndrive to the engine Tstat area, thinking that there may have been a restriction in that hose, there weren't any restrictions in what I observed, and I was able to blow thru it. I also removed the two upper radiator hoses and checked for any blockages, as they were fine.

So in the below photo I'm wondering if this circulator pump looks defective, do the blades look bad, are they normal? they all seem to be in the same shape as there aren't any irregularities and they all seem to be consistent with each other, I understand it is corroded, but I didn't have any leaks just yet, as this is another reason why I'm replacing it.

I guess I can wait for the new circulator pump to assess the overheating, or I will have to check the sterndrive impeller again.

Your thoughts on what I should check next. I believe I covered everything with respect to troubleshooting the restrictions in the hoses etc.

 

[1985 Century Mustang]

 

[Scott06]

View attachment 407290View attachment 407291

you probably were missing adequate water supply from the hose

circ pump looks fine

did you verify the gauge is accurate

 

[1985 Century Mustang]

you probably were missing adequate water supply from the hose

circ pump looks fine

did you verify the gauge is accurate

Yes gauge is correct. I agree the fins seem to look ok. However it's corroded. So I'll replace it anyways.

 

[Scott06]

Yes gauge is correct. I agree the fins seem to look ok. However it's corroded. So I'll replace it anyways.

they usually last the life of the boat in fresh water. have never changed one even on 30 yr old boats.

replace it if you want but that is not your issue here

 

[1985 Century Mustang]

Bone dry, I'm not getting any water coming up from the stern inlet hose to the Tstat housing. I'm assuming the new impeller is bad or I put it in wrong. Ughhhhh

 

[1985 Century Mustang]

It was fine for at least a week minimum as it was a brand new impeller, and now it seems the impeller isn't functioning. I'm draining the lower end oil and removing the lower leg to inspect the impeller.

 

[Scott06]

It was fine for at least a week minimum as it was a brand new impeller, and now it seems the impeller isn't functioning. I'm draining the lower end oil and removing the lower leg to inspect the impeller.

Was the old impeller missing pieces? If so they can get caught in the system in places like power steering cooler. Otherwise wonder if hose came of transom housing or possible new impeller failed have seen some after,Arlen ones where metal core spins within impeller

 

[1985 Century Mustang]

So I blew out all of the radiator hoses, inlet line, etc.. you name it, it didn't seem to have any restrictions, but then again I'm not 100% sure.

I pulled the lower leg and checked the impeller and keyway and it was fine. I replaced the impeller housing only, as the impeller was good. I also didn't guerilla down the 4 housing bolts, I made them snug. As I noticed the tighter I tightened the nuts the harder it was for the shaft and impeller to spin.

I put everything back together in with the new thermostat and it's running nice.. I'm not sure how it's fixed, but it's fixed. The temps run around 175 degrees in a slow neutral idle. However when I put it in gear, the temps drop down to 120 or so. So far so good. I'll do several runs in the driveway with the muffs before I attempt go out. I'm relieved, hopefully everything is good for an early boating season.

 

[cyclops222]

Reviving up a motor on a hose ? Great way to cook parts of the motor.

 

[1985 Century Mustang]

Reviving up a motor on a hose ? Great way to cook parts of the motor.

I never rev it. I go nice and easy

 

[cyclops222]

Rabbit ears are only good on RABBITS !!

 

[ESGWheel]

Mustang,
I have come to admire your determination and willingness to put yourself out there. This issue is just another in your “I want to get this fixed so I can go boating!” series. My hat is off to you sir!

And since the above may not be an appropriate post per se, I will add this > that picture in post #6 of the hose suggests it is well past its prime. Notice the cracking and split in it the picture. My general rule is hoses last about 10 years, but I admit to pushing much more but only if they have their integrity. Please consider replacing not just this one but all the others as well. Suggest doing the needed part number research this coming off-season (which I do not even what to think about!) and buying up the needed hoses over the winter with a plan to replace next spring. If need any help with how to find PNs or order, please PM me and I will do what I can to help.
Cheers!

 

[1985 Century Mustang]

Mustang,
I have come to admire your determination and willingness to put yourself out there. This issue is just another in your “I want to get this fixed so I can go boating!” series. My hat is off to you sir!

And since the above may not be an appropriate post per se, I will add this > that picture in post #6 of the hose suggests it is well past its prime. Notice the cracking and split in it the picture. My general rule is hoses last about 10 years, but I admit to pushing much more but only if they have their integrity. Please consider replacing not just this one but all the others as well. Suggest doing the needed part number research this coming off-season (which I do not even what to think about!) and buying up the needed hoses over the winter with a plan to replace next spring. If need any help with how to find PNs or order, please PM me and I will do what I can to help.
Cheers!

Thanks my friend I will definitely replace the hoses and clamps.