93 gamefisher 15 hp overheating only in gear

abohacik1

Recruit
Joined
Nov 21, 2016
Messages
4
i have changed impeller old 1 was intact when idle it spits water great hi idle does great to as soon as you put in gear it quits peeing any help would be greatly appreciated
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
How fast does it pump water when you start it?
Did it work before the impeller change?
You sure the impeller is the right one?
​You need to have 5 posts to add pics unless you use a photo sharing site.
Add pics of the pump body, top and inside.
​Pics of the wear plate and impeller.
 

abohacik1

Recruit
Joined
Nov 21, 2016
Messages
4
the stream is slow till you first rev it up in neutral than its fine as long as not in gear .Before the impeller change the stream was real weak all the time. Yes right impeller, looked just like the old 1. Wear plate is good .housing has some pitting. I will get pics tomorrow when i tear it back apart. Could it have anything to do with the exhaust plate on the side.
 

Bullie

Petty Officer 1st Class
Joined
Dec 20, 2014
Messages
300
Wear plates have fooled me before. I had problems that sounded similar to yours and was given advice by someone that has forgotten more than I will ever know about outboards, he told me that the wear plate can look fine but still be the issue when a new impeller won't work properly. I was resistant and argued a bit because the wear plate did look fine. But, a new one fixed the problem. Not saying that is the issue with your water pump but if nothing else is wrong you may want to try a new one.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
No Title

Yes the exhaust cover could be the problem .
Or inside the exhaust chest could be the problem.
​An easy check: Pull the thermostat and see if there is any corrosion or crud build up in there???
​The older model 15 hp. didn't have a thermostat.
If yours is a 93 it should have one.

The thermo in the pic was pulled from a small outboard that NEVER got flushed after use in salt water.
​The second pic IS a fresh water block that was taken care of. It's a 1974 6hp.

​I found the second problem when just running the motor for me and my neighbors personal use.
​I used my heat gun and shot around the motor.
One spot was at 170d.
​This would have eventually burned up the motor.
 

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abohacik1

Recruit
Joined
Nov 21, 2016
Messages
4
thanks for all the great info!!!!! i will be tearing apart today, an post pics also had an ole salty tell me there could be a pin hole in exhaust plate that would cause the same thing im describing...... i will keep you all updated
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
If you had a hole in the exhaust plate you'd probably have water on the plugs???
 

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
Just spit-balling here, but is it not spitting because the prop is pulling the exhaust and water out of the leg? The holes on the back side of the lower cowl are just idle relief holes, that will spit water out, but not really a great indication of water flow. I've never checked it while in gear so I don't know how much water comes out of the idle relief holes while the prop is moving, if any at all, I just check it idling to make sure it's spraying some water out.

Someone did a write-up on adding a telltale to the small Forces here on the forums. I've been thinking of adding one as it's a good indication of water flow, but never got around to it....
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
The pump is designed to push WAY more water than the motor could use.
Possible the impeller center core is slipping under load??
 
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