1966 johnson - 3 more questions

[jimh6278]

Should the copper tube from the pmp housing have a hole in it approximately 1 2/1 inches from bottom.

Should it have a tapered end. I can see numerous pliar marks on it.

I need to replace the thermostat gasket. Can I use a cork based blank to fabricate the item.

Thanks

Jim

 

[jimh6278]

Re: 1966 johnson - 3 more questions

And now that I look at it closely, the brass insert in the impeller is recessed enough so that the shaft can spin without engaging the slot. Hence it doesn't pump water because it doesn't move. The one i took out is not like that.

Lastly, how important is the "o" ring at the top of the shaft. there is none and from what i have read there should be. Will a Home Depot "o" ring work.

 

[Paul Moir]

Re: 1966 johnson - 3 more questions

There should be a hole, but usually it's up higher than that. 6 or 8 inches. I'm not certain about your model outboard though.

The end should be tapered. It should not have plier marks.

You can make the gasket if you like, just make sure you include all the various holes and don't block something important. If you've got it, I would just use a paper gasket with a little sealant, but the cork will do in a pinch. Cork works better where oil is involved.



Is there any evidence your outboard started life as a longshaft and was converted to short? FDL-nn model number? That might explain the plier marks and the hole being so close to the bottom.

EDIT: I'm not sure what you mean about the impeller. The hub is supposed to just slip over the driveshaft. Is there excessive clearance there?

Home depot o-ring will suit just fine - whichever one fits. The o-ring is important to keep water out of the splines and grease in. If it fails, the driveshaft will often rust into the crankshaft making removal impossible. Go light on the spline's grease on assembly, but make sure it's there.

 

[jimh6278]

Re: 1966 johnson - 3 more questions

Sorry - It is a 20HP. The model # on te plate says it is a FD-20C which is the short shaft - not 15" but 17" from what I can see.

The issue on the impeller is that the brass sleeve is recessed from the edge of the neoprene on both sides leaving enough room for the shaft to turn without the pin engaging. The one I took out is not like that. On the old one it is impossible for the shaft to turn without engaging and turning the impeller.

I did blow out the lines with air and they are not plugged so I am sure I found the problem. The shop sold me an after market impeller at does no engage. Un fortunately I don’t think I can take it back but I sure know what to look for tomorrow.

I bet the water tube was inverted. If I put the tapered end up the hole is 6 – 7” from the bottom. One of my problems is that the shop manual doesn’t get into that kind of detail.

Without this board and the members there would be a lot more ruined engines. I have been careful not to run it more than 30 seconds because of the cooling issue. It seems to be really strong.

Thanks for answering so quickly. I really appreciate it.

Jim

 

[F_R]

Re: 1966 johnson - 3 more questions

The tapered end goes down. The purpose is to make it easier to enter it into the pump grommet,

 

[jimh6278]

Re: 1966 johnson - 3 more questions

That is what I thought. I thought the sequence wast to set the top and guide the lower end in when raising the bottom unit.

thanks

 

[Paul Moir]

Re: 1966 johnson - 3 more questions

I'll reiterate that I'm not very familiar with the FD series, but are you suggesting that the water tube easily comes out of the midsection/powerhead?

 

[jimh6278]

Re: 1966 johnson - 3 more questions

The tube is snug but comes out. i know it is seatedin the rubber grommet at least 3/4 inches.

I am going to try someting tonite. File off the excess neoprene with a fine file so the brass insert is flush with the top of the impeller. Then use a thiin nylon washer as a shim to set the impeller in place and hopefully fully ingage the shaft pin.

I will also look for an impeller that doesn't have a problem but so far everything I have seen on the internet looks like the one I just bought.

 

[F_R]

Re: 1966 johnson - 3 more questions

True, there is a rubber grommet up in the housing. Try getting a "real" OMC/Bombardier impeller from ishopmarine.com

 

[Paul Moir]

Re: 1966 johnson - 3 more questions

I was just concerned about the condition of that grommet.

I would do as F_R suggests if possible. It's important for the hub to seal to the top of the impeller housing and the wear plate so the prime can be maintained. More modern outboards use a proper seal in that location.

 

[jimh6278]

Re: 1966 johnson - 3 more questions

F_R - Good source. That looks like the impeller I took out. Different from the one I got locally. And I just ordered it. They do not have my thermostat gasket though.

I already installed a new grommet. I don't think my problem is the tube.

Thanks again,