1965 9.8 Merc overheating

[shadowrider]

Re: 1965 9.8 Merc overheating

That is a lot of good information to know. You explained it well, I have seen impeller bits while changing one but never thought about accounting for all pieces. The pump tube on this motor is only 3/8", hard to imagine peices goning up there, but it makes perfect sense.
I have a few old outboard blocks laying around, I will look at them to see what you described. I can also use them to practice removing old studs. Problem is some water jacket bolts are below top of pan, so they would not be drillable for easy out purposes.
Those would need a nut welded on if they break. I am considering removing the leg from powerhead,( as merc850 suggests) as those bolts dont usually break in my experience. That would give me access to most of water jacket, would it not ?

 

[Laddies]

Re: 1965 9.8 Merc overheating

You probably don't want to here this either but the simplest to do the repair is to remove the powerhead it sounds like a big job but is not. Remove 2 nuts from the fuel line plug in on the bottom cowl, 3 screws for kill wire on port side of the engine, cotter pin on magneto link, choke shutter sping and the 6 nuts that hold the powerhead to the centersection. Then jar the powerhead sideways to lossen it and lift it off.

 

[shadowrider]

Re: 1965 9.8 Merc overheating

Actually, that is exactly what I wanted to hear, after looking at it, it looks very do-able, you just reassured that for me. I already checked availability on that gasket, its available and cheap. Also after looking at it , if lower bolts break, I would have to pull block to get to 3 lower bolts. Regards

 

[shadowrider]

Re: 1965 9.8 Merc overheating

Need some help here guys, I got powerhead loose from leg but I cant figure out how to undo the tiller shaft where in goes thru pan.???????? I did remove a bolt I thought was retaining the assembly, but I am obviously missing something.

 

[Laddies]

Re: 1965 9.8 Merc overheating

It's been awhile but I thought that you remove the cotter pin at the top lever of the spark advance shaft to remove the engine. The newer 110s you had to remove the 2 tilt screws in the handle, then the phillips screw that retains the shaft the pull the shaft out.

 

[shadowrider]

Re: 1965 9.8 Merc overheating

Thats what it looks like, but that shaft does not want to budge. I will give it another try. If no luck, I will post pics to jog some thought.

 

[shadowrider]

Re: 1965 9.8 Merc overheating

Still no luck, here's some pics. Thanks for your help. Shadowrider

 

[Laddies]

Re: 1965 9.8 Merc overheating

I don't know the need to remove the linkage there, usually we remove the linkage at the top lever item #17 some are bolts and some use cotter pins then just swing the lever out of the way, won't that work on your engine?
http://www.ishopmarine.com/ishop/js...cCatFilter=MM&eCatSupFldr=supplier-050-025-MM

 

[shadowrider]

Re: 1965 9.8 Merc overheating

Well, you're right, I was trying to lift pan off leg. However, I did not find any sign of blockage. Blew air through system and down pipe, nothing there. Now what ? Getting a little discouraged now.

 

[Laddies]

Re: 1965 9.8 Merc overheating

You can test the pump for output at the top of the tube with a electric drill in a tank, then remove the exhaust plates

 

[bktheking]

Re: 1965 9.8 Merc overheating

I took this image from a 66 parts diagram. Had some fun fixing a 7.5 last summer that would pump, then wouldn't then would. I pulled my hair out.

The bottom grommet going into the gearcase was missing. As soon as I replaced that grommet it was a new motor. That being said, the tube going into the grommet in the pump should be tight too.
The third issue i've heard of it that plate over the impeller was missing on a motor and it wouldn't pump properly either, just something to add.

Compare your motor to the diagram and make sure all the washers, plates and grommets are all there and in tact, it's vital.

 

[shadowrider]

Re: 1965 9.8 Merc overheating

I believe everthing is there, I did replace some seals etc, will double check everthing.
Drill spin test will be interesting.

 

[shadowrider]

Re: 1965 9.8 Merc overheating

I have an update. I did the drill spin test and pump is doing its job. So I pulled water jacket and broke 3 of 8 bolts-which is better than I expected. I also pulled cylinder cover. I found 2 impeller bits inside water jacket. They were very small about half the size of a grain of rice, (about the same size as some passages), Also a lot of white crust. I have ordered new gaskets and bolts, and believe that those impeller bits were the problem. Laddies nailed it again. Thanks Laddies. I will post results as they develope.

 

[shadowrider]

Re: 1965 9.8 Merc overheating

Well, it's been a while since my last post, been busy, got the parts to fix and found time to fix it ! Overheating problem solved. While i had it apart I took a rifle cleaning rod with a .22 cal brush and scrubbed out as much white crust as I could reach and rodded out all passage holes. Motor pumps well and does not get hot ! Thanks to all who helped steer me in the right direction. I only broke 3 studs off on the jacket, was able to repair all 3 and get her seaworthy again. Regards, Shadowrider

 

[Maxz695]

Re: 1965 9.8 Merc overheating

comgrats I was hoping you wouldn,t have to resort to that unless all eles faild. I,m glad you have put this thing to rest. Enjoy your boat. PS. I may be doing the same thing next week if my WP doesn,t work but at least I already have a whole head set (no bolts I shiver at this)