can an overheated engine affect the lower unit??

[arty007]

i took the boat out last week after correctly setting the timing on it. boat ran fine, but when i bought it... it came with an automotive distriburator so i replaced it with a marine one and adjusted the timing.(timing was at 25 btdc before and now its at 8 deg).
as soon i began to throttle up the boat bogged down and just died on me i was a bit embarrased as all this happened really close to the launch:redface: anyways, i oppened up the dog house and began to tinker with it, at first i was blaming the timing and i kept trying to adjust it to a better position to get it to run right. after many attempts i managed to get her going but, could not go more than about 15 mph or the engine would die. i ran it like this for the day at low speeds to get the kids on the tube atleast, i noticed ahe was hot i could only hold the exhaust manifolds for say.. 4 seconds so it got pretty hot! and when i got home i found that the carb was the problem.
( running rich) i had it rebuilt, tripple checked the timing, and she is back to normal. the problem now is that i noticed after i ran her on muffs yesterday and took the muffs out there was a trickle of water coming from the front of the lower unit the next day. Could i have damaged the impeller or something else back there running the boat hot? btw, the impeller was replaced 6 months ago. any thoughts are greatly appreciated thx.

 

[jerryjerry05]

Re: can an overheated engine affect the lower unit??

No overheat shouldn't affect the drive.If you want to make your drive last longer.Install a drive shower.Then a reservoir system for oil.J

 

[paultjohnson]

Re: can an overheated engine affect the lower unit??

If the water is coming out of the little drain hole on the front of the lower uniy--not a problem in itself Is it a mercruiser ir what?

 

[Brentathon]

Re: can an overheated engine affect the lower unit??

***Yes, overheating can hurt the drive.
When I overheated, the drive started to make a louder gear-whining type noise, after using the boat just 2 times later, a complete mechanical failure occurred (don't know what, exactly), where the drive started to make a loud knocking noise, and was not transmitting power.
Un-cooled exhaust gasses are extremely hot.
I also melted an impeller housing from overheating, one time.

 

[arty007]

Re: can an overheated engine affect the lower unit??

No overheat shouldn't affect the drive.If you want to make your drive last longer.Install a drive shower.Then a reservoir system for oil.J

a drive shower? gotta look in to that...

 

[arty007]

Re: can an overheated engine affect the lower unit??

If the water is coming out of the little drain hole on the front of the lower uniy--not a problem in itself Is it a mercruiser ir what?

yeah it seems to be coming from the front where the lower and upper housing meet. the reason im worried is because it didn't leak for that long a period before now it leaks days later.

 

[BAproject]

Re: can an overheated engine affect the lower unit??

The big question is, were you running the boat with O/D trimmed to high???? That would be a problem. I am surprised that your carb would lead to such problems.

What set-up do you have?

 

[arty007]

Re: can an overheated engine affect the lower unit??

***Yes, overheating can hurt the drive.
When I overheated, the drive started to make a louder gear-whining type noise, after using the boat just 2 times later, a complete mechanical failure occurred (don't know what, exactly), where the drive started to make a loud knocking noise, and was not transmitting power.
Un-cooled exhaust gasses are extremely hot.
I also melted an impeller housing from overheating, one time.

probably best to remove the lower unit and inspect.

 

[arty007]

Re: can an overheated engine affect the lower unit??

The big question is, were you running the boat with O/D trimmed to high???? That would be a problem. I am surprised that your carb would lead to such problems.

What set-up do you have?

its an i/o mercruiser 260 1978.
and no... i was not running with the drive up at all, it all seems normal now hopefully that problem is fixed,now im just worried about the constant leak in the drive.

 

[sethjon]

Re: can an overheated engine affect the lower unit??

***Yes, overheating can hurt the drive.
When I overheated, the drive started to make a louder gear-whining type noise, after using the boat just 2 times later, a complete mechanical failure occurred (don't know what, exactly), where the drive started to make a loud knocking noise, and was not transmitting power.
Un-cooled exhaust gasses are extremely hot.
I also melted an impeller housing from overheating, one time.

I think your drive problem was a coincidence. Overheating in the engine will not do anything to the drive.

 

[Brentathon]

Re: can an overheated engine affect the lower unit??

I think your drive problem was a coincidence. Overheating in the engine will not do anything to the drive.

I'm going to have to disagree with you......that would mean, that after 16 years of operating the boat, the O/D just so happened to start making a whining-gear noise, at the exact time I overheated the engine? The odds of that would be...??........

If I recall the college course I took on internal combustion engines....exhause temps of aro 800 F are not uncommon; and without any water to cool the exhaust, that's some hot gas going through a drive.