6hp evinrude overheating

[madmaxsupra]

Hello everyone,

I'm new here, I'm looking at a little aluminum boat to buy, the guy said that the motor overheats, but the previous owner said they put a new water pump in it. Is there something else that could be causing this other than the water pump? maybe a plugged passage on the powerhead or something? I don't know a lot about outboards, but I am good with mechanics.

Thanks

Eric

 

[iwombat]

Re: 6hp evinrude overheating

It's probably a stuck thermostat. That being said, you should be very wary of buying an outboard with a history of being run until it overheats. You could be inheriting a full rebuild project.

 

[madmaxsupra]

Re: 6hp evinrude overheating

It's probably a stuck thermostat. That being said, you should be very wary of buying an outboard with a history of being run until it overheats. You could be inheriting a full rebuild project.

Yea, that is a good point, so what does it cost to do a rebuild on one of those engines anyway? Like I said before, I don't have a lot of mechanical experience with outboards, but an engine is an engine

Eric

 

[iwombat]

Re: 6hp evinrude overheating

For what it would cost you in a rebuild, you could easily find a used one. You'll want to give that motor a compression test at the very least. Check the powerhead for any discolored paint etc. If it overheat until it stopped running a few times I'd be looking for another deal, or see if you can get the motor tossed in for free.

Then, you can look for a used one of the same vintage and have a spare parts motor.

 

[madmaxsupra]

Re: 6hp evinrude overheating

Yea, it was overheated till it stopped running, I'm not sure how many times....overheated engines are generally a bad thing to deal with, I agree. All kinds of things warp and weaken, etc. I may go out and take a look at it and see what the deal is with it, he is asking 400 for the boat and motor...maybe I can talk him down if the motor is a POS.

For what it would cost you in a rebuild, you could easily find a used one. You'll want to give that motor a compression test at the very least. Check the powerhead for any discolored paint etc. If it overheat until it stopped running a few times I'd be looking for another deal, or see if you can get the motor tossed in for free.

Then, you can look for a used one of the same vintage and have a spare parts motor.

 

[iwombat]

Re: 6hp evinrude overheating

Usually what happens with an outboard is it blows the head gasket. If it's not fixed right away you get water intrusion into the crankcase. Then, it all starts to unravel from there.

A compression check should tell you if you've got a blown gasket. If you do, and he'll let you, pop the head and see how bad things are inside.

 

[madmaxsupra]

Re: 6hp evinrude overheating

Sounds about like cars with aluminum heads thanks for the info. will a regular automotive compression guage work on it? or do I need a special fitting?

Thanks

Usually what happens with an outboard is it blows the head gasket. If it's not fixed right away you get water intrusion into the crankcase. Then, it all starts to unravel from there.

A compression check should tell you if you've got a blown gasket. If you do, and he'll let you, pop the head and see how bad things are inside.

 

[iwombat]

Re: 6hp evinrude overheating

Regular old automotive. You'll need to use the short fitting, or you'll bottom out. Look for the cylinders to be even. With a rope pull, you're probably looking at 70psi+ for a good reading with a cold motor depending on how well you can pull.

 

[Vic.S]

Re: 6hp evinrude overheating

You don't say what age the motor is but the recurring problem I have with a 1984 6hp is that corrosion squeezes the grommet at the top of the water tube over the top of the tube until it cuts off the water flow. Water from the pee hole is reduced to a trickle and loads of steam comes out of the exhaust relief at the top of the leg.

With the lower unit off make sure you can get a good flow of water through.

You should get a good stream from the pee hole and coming down the leg from the outlet. Maybe you will have to remove the thermostat to check the latter.

If you can get a flow from the pee hole but not from the outlet inside the leg then the passages in the head are blocked.

If the paint on the head is discoloured due to overheating you could have some of the other trobles mentioned