89 Evinrude 25HP Strange Problem

Hello,

So I picked up a boat for a cheap price and it came with a well used 1989 Evinrude 25HP outboard with long shaft. The motor had been sitting for a while so I had a mechanic replace the impeller and leg oil. The motor fired right up and was pushing lots of water.
I took the boat to the lake for the first time and everything went well for about 15 minutes. We went through all of the RPM's and the motor ran perfectly.
All of a sudden the motor lost thrust and started to rev up. When I throttled down everything seemed fine so we kept going. We throttled up again and after a few seconds it happened again. I turned around and noticed that there was now no water coming out of the tell tale so I shut the motor off. It was hot so we let it sit for 5 minutes. I checked over the intake grate on the leg and there was nothing clogging the intake.
We fired the motor up again and still no water. We shut it down and paddled home.
I took the water line apart today and there is nothing clogging the tell tale.

The symptoms were like a clutch slipping in a car. The motor rev'd quite high but when I throttled down the motor was still in gear. Is that a common symptom of overheating? I am worried about the bottom end (gearcase) but there was no grinding or vibrating, nothing.

Think the brand new impeller failed?? What else could stop the water from flowing? Any thoughts??

Thanks!

Re: 89 Evinrude 25HP Strange Problem

For the slipping prob, you could have a spun prop hub or for the worst case happening the splines on the drive shaft may be slipping causing the water pump to stop pumping and the slipping prob..

Re: 89 Evinrude 25HP Strange Problem

boobie said:

For the slipping prob, you could have a spun prop hub or for the worst case happening the splines on the drive shaft may be slipping causing the water pump to stop pumping and the slipping prob..

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Thanks for your reply. The motor will still run and operate properly at times. Obviously I'm not using it now unit the water pump situation is fixed. Do you think that the motor could still operate if the splines on the drive shaft were gone?

I'll take the prop off tomorrow and check for damage there.

At the bottom of the drive shaft, what holds on the drive gear on an Evinrude motor??

Re: 89 Evinrude 25HP Strange Problem

The splines in question are at the top of the driveshaft where it connects to the powerhead. If it is as suspected I wouldn't run it as it will only get worse with use.

Re: 89 Evinrude 25HP Strange Problem

TrueNorthist said:

The splines in question are at the top of the driveshaft where it connects to the powerhead. If it is as suspected I wouldn't run it as it will only get worse with use.

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So if that is the case, does the drive shaft have to be replaced or is it usually the splined piece coming off of the power head?

I'm having troubles understanding how the motor can go into gear and spin the prop but not allow the impeller to push water? That doesn't make much sense to me. If the prop is spinning than so is the drive shaft.

I agree that this could be the issue but any idea why the water pump just stopped working??

Thanks

Re: 89 Evinrude 25HP Strange Problem

The other thing it could be is bad water pump and spun hub in the prop Two things happened at once.

Re: 89 Evinrude 25HP Strange Problem

sounds like a bad waterpump housing just did this with a 15 hp evenrude the whole kit is about 80 bucks and its worth it to do the whole thing now the engine is cold as ice also check the thermostate if it has one to make sure its not seized. As far as the slipping goes i had this happen yesterday with my 33 hp johnson the guys here told me to change the prop as it maybe spun and thats what it was when in high rpm, it slipped like crazy but in low ran fine give that a shot it maybe a cheep fix.

Re: 89 Evinrude 25HP Strange Problem

jbabcock said:

sounds like a bad waterpump housing just did this with a 15 hp evenrude the whole kit is about 80 bucks and its worth it to do the whole thing now the engine is cold as ice also check the thermostate if it has one to make sure its not seized. As far as the slipping goes i had this happen yesterday with my 33 hp johnson the guys here told me to change the prop as it maybe spun and thats what it was when in high rpm, it slipped like crazy but in low ran fine give that a shot it maybe a cheep fix.

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Thanks. I read up on spun prop symptoms and that does indeed sound like the problem. Seeing as the water pump isn't working, I have no way of testing to know for sure.
Would any of you guys recommend getting a new hub? Or just buying a used or new prop with hub?
How do you remove the hub from inside the prop?

As for the water pump, I guess I'll have to take it apart to find out what's wrong. Bummer if my brand new impeller is gone!

Re: 89 Evinrude 25HP Strange Problem

the impellor is likely fine the housing or pump body has a couple very small holes in it to allow flow if those have been sealed buy a melted off piece of the old impellor that will bugger it up also check to make sure the water tube is connected and seated properly and the thermostate isnt seized i know in the 15 you have to remove basicly the whole head of the motor to get at the thermostate really not a great design.

Re: 89 Evinrude 25HP Strange Problem

jbabcock said:

the impellor is likely fine the housing or pump body has a couple very small holes in it to allow flow if those have been sealed buy a melted off piece of the old impellor that will bugger it up also check to make sure the water tube is connected and seated properly and the thermostate isnt seized i know in the 15 you have to remove basicly the whole head of the motor to get at the thermostate really not a great design.

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Thanks a lot. I'll have to take the water pump apart and inspect. I was told that my motor doesn't have a thermostat. The model number is E25ELCEB. Can anyone confirm that this motor indeed does not have a thermostat?

How about the prop? Am I able to buy a new hub or should I get a whole new prop/hub? Are the hubs universal or do I need a kit that is specific to my motor/prop?

Re: 89 Evinrude 25HP Strange Problem

Viking59 said:

Thanks a lot. I'll have to take the water pump apart and inspect. I was told that my motor doesn't have a thermostat. The model number is E25ELCEB. Can anyone confirm that this motor indeed does not have a thermostat?

How about the prop? Am I able to buy a new hub or should I get a whole new prop/hub? Are the hubs universal or do I need a kit that is specific to my motor/prop?

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It has a thermostat and you don't have to remove the power head to change it. Just take off the cylinder head cover (#46). Also, replace gaskets (49 & 17)...

http://www.marineengine.com/parts/j...rer=Evinrude&section=Cylinder+&+Crankcase

Re: 89 Evinrude 25HP Strange Problem

rehubbing the prop really isn't a diy...call a prop shop in your area, or a marine dealer and ask who they use, and be certain to ask the price first as it may be close to the cost of a new aluminum prop...iboats had some great prices recently

Re: 89 Evinrude 25HP Strange Problem

From what the local prop dealer told me here it dosnt really pay to have it rehubbed its kinda a hit or miss thing as he said the damage has been done when the prop is spun so it likly wont seal properly and for what youll pay to have it done it will be close to the cost of a new prop mine was 60 to re hub and 90 for new with a year warrenty.

Re: 89 Evinrude 25HP Strange Problem

jbabcock said:

From what the local prop dealer told me here it dosnt really pay to have it rehubbed its kinda a hit or miss thing as he said the damage has been done when the prop is spun so it likly wont seal properly and for what youll pay to have it done it will be close to the cost of a new prop mine was 60 to re hub and 90 for new with a year warrenty.

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Hey guys,

I've got the leg apart and everything looks good so far. No idea why the water isn't pumping. I'm going to put it back together tonight and see what happens. If the water is pumping I'm going to take the boat to the lake and see if the prop spins. I've marked a paint line across the prop and hub.

The part that the drive shaft plugs into at the top of the motor, what is that called? I don't see it an any of the diagrams. Does anyone have a part number? I'm hoping that's not the problem but want to be prepared if it is. I'm hoping it's the prop hub and I'm going to buy a new prop if it is.

Thanks