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Evinrude 25hp 2stroke 2 cyl overheating mid section

D

Davisjoel

New member
Hey fellas, my out E'rude has been playing up a bit, it will start fine, idle fine but when I open her up she will go good for about a minute then she will start farting and spluttering until I back off to a certain rev and the mid section is really hot, I know it farts and splutters coz of overheating but just wanna know what could be causing this, only had new impeller, thermo and carby cleaned this time last year, could it be a stuck thermo?
cheers
 
kimcrwbr1 said:
Is the motor used in salt water? Do you flush it with fresh water after each use? Lake water has alot of silt and minerals and is not considered fresh water. Pull the thermostat cover off of the head and look inside. Put it in a barrel of water and start it with the thermostat cover off to see if water gushes out.
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Yeah mainly salt water use, I will give that a go now, what will that mean if water gushes out?, I was going to take the thermostat out see if its stuck then put it back ttogether, thanks for the replies I appreciate it.
 
That doesn't matter right now... you need to see if the water pump is doing it's thing, and the cooling jacket isn't plugged. It should run long enough even if the plug wire get soaked to tell you if the water is actually circulating through the block.
 
bill_w said:
That doesn't matter right now... you need to see if the water pump is doing it's thing, and the cooling jacket isn't plugged. It should run long enough even if the plug wire get soaked to tell you if the water is actually circulating through the block.
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As I'm not mech smart, the tell tail and the exhaust outlet are both dispersing water, can the water pump still be blocked or not working? Just wondering before I pull off the cover and wreck the gasket coz its really hard to get off.
cheers
 

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What made you decide that it was overheating? Did the warning horn sound?

I had a very similar problem with a 1991 25HP Evinrude. I took it to the dealer
and they fixed it.....but didn't tell me what was wrong! Might have been overheating.
 
kimcrwbr1 said:
Is the motor used in salt water? Do you flush it with fresh water after each use? Lake water has alot of silt and minerals and is not considered fresh water. Pull the thermostat cover off of the head and look inside. Put it in a barrel of water and start it with the thermostat cover off to see if water gushes out.
Click to expand...
Hi Kim
i did what you mentioned, water was gushing out, I tested the thermostat in boiling water too, to see if it opened and closed when it cooled down which it did, so now I don't think it would be the thermostat or water pump or impeller? Any other thoughts? Cheers Joel
 
kimcrwbr1 said:
With a screwdriver pry out a little bit on the thermostat and put a string in the valve then hang it in the center of a small pot of water and hold a meat thermometer right next to it. It should fall off the string around 140 degrees. Is the exhaust cover getting hot on the side of the powerhead the outer cover shold not get hot. IDK maybe there is blockage downstream from the thermostat and exhaust cover you never mentioned if it has seen salt water maybe try running it in a barrel with saltaway in it to clear out all the cooling circuits. You can also try spraying high pressure water into the thermostat hole and see how much water comes out the prop. Another possibility is if it was stored in the running position and not properly flush out the engine will not drain out properly. Allways flush it after each use and store it in the running position so it completely drains out.
Click to expand...

Ok I will give that a go, thanks Kim I appreciate the help
 
kimcrwbr1 said:
With a screwdriver pry out a little bit on the thermostat and put a string in the valve then hang it in the center of a small pot of water and hold a meat thermometer right next to it. It should fall off the string around 140 degrees. Is the exhaust cover getting hot on the side of the powerhead the outer cover shold not get hot. IDK maybe there is blockage downstream from the thermostat and exhaust cover you never mentioned if it has seen salt water maybe try running it in a barrel with saltaway in it to clear out all the cooling circuits. You can also try spraying high pressure water into the thermostat hole and see how much water comes out the prop. Another possibility is if it was stored in the running position and not properly flush out the engine will not drain out properly. Allways flush it after each use and store it in the running position so it completely drains out.
Click to expand...

It is a salt water motor, I have realised that someone has drilled a bleed hole in the thermo and when I took the thermo out there was crud blocking the self made bleed hole, I did what you mentioned I used high pressure water in the thermo hole. And it didn't seem to go anywhere but back out the thermo hole, nothing came out the prop, I had it in gear, so I'm thinking blockage and probably should give it a good run with saltaway, that should clear any lower blockage? Cheers joel
 
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