40 HP over heating

circle hook

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I have a model# 40E 71B and I checked the water impeller by dropping the lower unit and with a spinning hand drill in a bucket of water the pump is working I looked in the repair manual is states that 40 HP johnsons have a water thermostat I can not for the life of me be able to find it, if it does not have one what would be the next step to finding this problem Thanks Bob
 

bktheking

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Re: 40 HP over heating

Check your compression, you may have a blown head gasket and you can't find a stat cause it doesn't have one. How do you know it's overheating? Did you measure the temp with a laser thermo, is the paint discoloured on the head?
 

circle hook

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Re: 40 HP over heating

to hot to the touch running it in a barrel the block is to hot and the mid-section also is very hot, the compression in both cylinders was fine but the top cylinder had a striped spark plug and a heile coil was put in, could the block be pluged up with crap and if so how would you access it to clean it out, Thanks Bob
 

kenmyfam

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Re: 40 HP over heating

to hot to the touch running it in a barrel the block is to hot and the mid-section also is very hot, the compression in both cylinders was fine but the top cylinder had a striped spark plug and a heile coil was put in, could the block be pluged up with crap and if so how would you access it to clean it out, Thanks Bob

Salt water use motor ???
 

bktheking

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Re: 40 HP over heating

to hot to the touch running it in a barrel the block is to hot and the mid-section also is very hot, the compression in both cylinders was fine but the top cylinder had a striped spark plug and a heile coil was put in, could the block be pluged up with crap and if so how would you access it to clean it out, Thanks Bob

Could be, is it a salt water motor? If the lower comes off easily, pull it and try forcing water into the pickup tube.
 

circle hook

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Re: 40 HP over heating

yea it was a salt water engine and when i had the impeller out it was full of corrision, I replaced the impeller and tested the lower unit in a bucket of water with a hand drill on the drive shaft and she pumps, but still after putting her back together she runns hot as hell, what if I hook a garden hose directlly to he water pickup and force water into the block do you thing this can clear it out Thanks Bob
 

bktheking

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Re: 40 HP over heating

Not since it's a salt water motor, you are going to have to use a product like salt away and flush it out. If that doesn't work it could be powerhead removal and manual cleaning time, salt water causes these issues.
 

circle hook

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Re: 40 HP over heating

salt away where can I get this and how do you use it, in a drum and recirculate it.
 

bktheking

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Re: 40 HP over heating

salt away where can I get this and how do you use it, in a drum and recirculate it.

http://www.iboats.com/Kwik_Tek_Salt...23421088--**********.306080898--view_id.21160

Comes with a flush attachment, problem is your motor is the old style, you may have to rig something up to connect to the water tube going into the powerhead. Ever see what salt can do to water jackets??? Look at the pic, those water jackets are plugged solid, no way could water flow to cool that motor.


block%20salt%20corrosion.jpg
 

circle hook

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Re: 40 HP over heating

sounds great first I need to get water to flow through the block, I can make an adaptor with the lower unit off to the water pick up tube, but is it safe to run the engine with out a lower unit attached even if I keep it at idle speed, and last can I buy this salt away in a box and mix a 55 gallon drum of water and just let the engine run for an hour or so after I put it back together Thanks Bob
 

kenmyfam

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Re: 40 HP over heating

Nice photo. Pretty much sums the salt issue up if not regularly flushed.
 

bktheking

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Re: 40 HP over heating

It won't be safe until you get water flowing, if you had water flowing you could run it all day at idle with the lower unit off so long as you are supplying something to keep it cool. This is going to be a coin toss, it's guess work at this point. Order the product and try it. If your block look like the pic I posted you will have a hell of a time flushing out a powerhead with that much salt, that's a job for a drill.


I'm not one for quick fixes either, i'd have the head off your motor so fast I wouldn't be here typing. I'd be interesting in seeing how bad it is and then figuring out if I'd have to dig deeper, but hey, that's me.
 

circle hook

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Re: 40 HP over heating

to tell you the truth I am the same way, if I make an adaptor to the water pick up tube with the lower unit off with the water on full blast where should the water outlet be on the back of the mid section near the top, if so then this may work water pressure from the impeller is nothing like straight off the tap.
 

bktheking

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Re: 40 HP over heating

Agreed, I guess it's all dependent on the salt build up. That's an old motor and if it has logged a pile of hours in salt without proper flushing god knows what it looks like inside, the old impeller would have been good evindence.
 

Dirt_Bag

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Re: 40 HP over heating

I use mine in salt all the time. Its a 84 old style so I back into a lake or the river and run it, Before I bring it home. Salt hammers everything.
 

circle hook

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Re: 40 HP over heating

well I guess its going to be home made power flushing, then use that salt flush and put back together. lets see what happens will reply back with an answer, just have to wait for this snow storm now to leave the New York area

Thanks again for all the in put guys have a safe & happy holiday season Bob
 

kenmyfam

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Re: 40 HP over heating

well I guess its going to be home made power flushing, then use that salt flush and put back together. lets see what happens will reply back with an answer, just have to wait for this snow storm now to leave the New York area

Thanks again for all the in put guys have a safe & happy holiday season Bob

Keep us all posted on what you find. We love photos !!!:)
 
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