1968 Evinrude 9.5 over heating

[Will57]

I picked up this old Evinrude Speedtwin 9.5 for scrap and got it running. Its over heating at high speed. My thermo scanner shows the water temp coming out at 95 at an idle and 180 at high speed. I pulled the thermostat cover off and found the thermostat has been removed so I assume someone else has been chasing this problem also in the past. The mag timing seems right as it lines up with the mark on the timing make unless I'm not looking at it right. Why would it get hot with no thermostat? It would seem with water free flowing through the block it would run cold? Any ideas?

 

[Will57]

I should mention it seems to be pumping plenty of water out the port.

 

[Crosbyman]

if it gets hot water restrictions need to be cleared.
start with pulling the cyl head .(just a few bolts and a gasket) to inspect the water jackets for accumulated crud.

most of your free flowing water does not cool the water jackets it goes in and out the back ....

check the water jackets

 

[909]

I had a similar issue where the impeller would pump water but not enough. Installing a new one solved it.

 

[Will57]

I pulled the head and was surprised that there was not that much corrosion. I expected much more given the age of the engine. I took my dermal tool with a round chain saw stone and cleaned up the water jackets the best I could and then finished with rolled up emery 180 grit paper and then blew out everything with compressed air. Both the head and cylinder jackets look good now. I pulled the lower end and blew up through the water inlet tube with compressed air and received lots of air coming through the cylinder walls so I assume there is no blockage.. Iv ordered a new pump kit and lower seal kit for it. Question, I work on a lot of vintage cars and trucks. On those its normal when I replace a head gasket I coat the gasket and metal surfaces with copper coat for a good seal, Should I do the same with this?

 

[Crosbyman]

no need for goopy stuff ..I have never used it. just tighten up to specs run a while then retorque to specs

your engine should run fine like my 9622a if no mechanical issues and compression is above 65-70 psi .
just saw comment from 909 about cheaper impellers not pushing enough water to cool .... maybe you should go for OEM stuff for peace of mind.

btw some pumps have VERY small holes that must be cleared for proper operation ( I think it prevents air locks or something

see picture... check housing for your's

 

[909]

One instance was an aftermarket impeller that wouldn't pump enough water. On another instance, the OEM pump simply had bent (warped) fins that didn't reach the pump housing. It appeared to work fine from the outside before I took it apart and would still pump some water , but not just not enough. On both instances a new OEM impeller solved it.

I agree with Crosbyman. The difference between aftermarket and OEM pumps are $10-$20. Find elsewhere to budget. This part is vital to the life of your outboard.

 

[Will57]

I did order an OEM impeller kit from MarineEngein.com. They did not have a lower unit seal kit for my 9822D so I winged it and found a kit on Ebay. I looked up the head bolt torque and it should be 96 to 120 inch pounds so I will go to the middle with 110. Now its a waiting game for the parts. What is the difference between a 9822 (B) (M) and D? Will most parts interchange?

 

[Crosbyman]

when suffix letters change my understanding is that it reflects mostly production changes I doubt this will be of concern for your problem

 

[Grub54891]

it. Question, I work on a lot of vintage cars and trucks. On those its normal when I replace a head gasket I coat the gasket and metal surfaces with copper coat for a good seal, Should I do the same with this?

What? Never apply sealant to a head gasket. If machined properly no sealer is needed.

 

[440roadrunner]

it. Question, I work on a lot of vintage cars and trucks. On those its normal when I replace a head gasket I coat the gasket and metal surfaces with copper coat for a good seal, Should I do the same with this?

What? Never apply sealant to a head gasket. If machined properly no sealer is needed.

That is a blanket statement and not always true. I'm sure you meant this in the context of this thread, but that is not what you said. It is common to use a "light" sealer such as copper coat or even aluminum paint on metal shim head gaskets such as used in some automotive engines.

Composition ones? Never.

 

[Grub54891]

That is a blanket statement and not always true. I'm sure you meant this in the context of this thread, but that is not what you said. It is common to use a "light" sealer such as copper coat or even aluminum paint on metal shim head gaskets such as used in some automotive engines.

Composition ones? Never.

Well, I forgot about those type of gaskets. thanks' for the reminder. lol Also I've read that those metal shim gaskets may contain asbestos. No big deal, and the old timers would soak them in water to swell them back up and let them dry for re-use.

 

[kbait]

On those older ones.. I have replaced impeller and still had overheat issue. Got a used base plate and pump housing (timsoutboard.com). Solved the issue.
Pump housing and base plate looked fine.. who am I to argue w/success?