1961 Scotty 3.6 cooling problem

twocyclemania

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Just resurrected a 1961 Scotty 3.6. that has no corrosion and apparently very little use. Got the piston unstuck, cleaned the carb, and transplanted an OMC coil and got her fired up. Only problem is that something is wrong with the cooling. She's not putting any water out the exhaust/discharge hole at the top of the lower unit. I checked the passages of the head when I had it off and the pipe through the lower unit and everything is clear. The impeller is the original round type that works of a concentric. The motor was not used very much and the impeller is still fairly pliable and though I will replace it I have a doubt that it's the problem. Any suggestions are greatly appreciated. thanks
 

F_R

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Re: 1961 Scotty 3.6 cooling problem

Well, it's gotta either be the pump or else it is plugged up somewhere. Or you don't have it in the water deep enough. That is a super simple system, not much to go wrong.
 

twocyclemania

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Re: 1961 Scotty 3.6 cooling problem

Well, it's gotta either be the pump or else it is plugged up somewhere. Or you don't have it in the water deep enough. That is a super simple system, not much to go wrong.

Thanks for the reply F_R: I have it in a barrel and it's plenty deep. I ran both a rod and water through the pipe in the leg. I also ran water through both sides of the power head; everything was clear. The intake screens are also clean. I agree; its a simple system and that's why it's so strange. I turned the driveshaft and the impeller turns as it should. I don't have any answer other than I'll try a new impeller but the old one looks pretty good.
 

F_R

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Re: 1961 Scotty 3.6 cooling problem

So, that one has the wobbler type pump? The impeller should be a close fit on the eccentric. It should just touch the housing at some point on the outside diameter. There should be a space on the other side. It should be the same height as the cavity depth. As the eccentric rotates, that space on one side progresses around to the discharge side, then disappears, only to reappear again on the intake side. As it does so, it takes in a gulp of water at the intake side and moves it around to the discharge side. Most problems are caused by worn parts that no longer fit as designed, or the impeller rubber has swollen up from oil getting on it.
 

1946Zephyr

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Re: 1961 Scotty 3.6 cooling problem

There is a guy in AOMCI who specializes in the old Scotts and should still have a good supply of parts. There's a good chance he can help you out. I can't remember his name, cuz it's been a while since I've done business with him. But if you post a want ad at the site, he'll probably answer it and assist you.
 

1946Zephyr

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Re: 1961 Scotty 3.6 cooling problem

Yes!! That's him. He seems to have a decent supply of Scott parts, especially for these old 3.6's. At least he did when I had a need.
There was a fellow local to me who had a good supply of Scott parts too, but he closed it up several years back. I've owned, fixed and sold a few Scotts in my day and they're not bad motors. Hopefully, there's more parts available out there now, than there was before. The old 5's, 10's and 16's are relatively common in the Scott group.
I picked up a beautiful old 1956 Scott Attwater 16 once. Paid 20 bucks for it and got it running, by just replacing the plugs in it. These things took the 17mm plugs and I believe it was the D9J or something to that affect.
 

twocyclemania

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Re: 1961 Scotty 3.6 cooling problem

It's still overheating and not pushing any cooling water out the back port at the top of the leg. I did replace the impeller (a new one) though I could find no fault with the old one. She runs great but is still overheating. I also polished the plate cavitation? plate that contacts the top of the impeller. The impeller was my last hope. The cooling system is simple enough. I don't know where to go from here. Any more advice? thanks
 
M

mrcrabs

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Re: 1961 Scotty 3.6 cooling problem

I got nothing better to do so I thought I would toss my penny in this morning,
I have been looking at a diagram of the McColloch 3 1/2 which claims to be the former scott 3.6 with the wobble pump, could there be a chance your water intake screen is stoped up? that looks like a tender area for trouble, or maybe your missing a piece in there some where.

if you need a manual ebscohost public library has one, Im looking at it now.
http://search.ebscohost.com/login.aspx?direct=true&db=s9h&AN=24327821&site=serrc-live
 

twocyclemania

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Re: 1961 Scotty 3.6 cooling problem

mrcrabs: Thanks for the reply. I did check the water intakes (one on each side). The screen is missing from one and though it looked okay I blew the screen out with starting fluid. Though I've had intake screen type of problems before with other motors I don't think that's it. That is something that can be overlooked. I ran her afterwards in a tank and still no water pumping. This motor is so simple; I can't believe it's not cooling. At this point my only alternative is to pull the power head again and put a drill on the shaft to see if it's pumping to the power head. At least that will tell me if the problem is from above or below. Thanks for the link to the diagram. I'll take a look at it and see if that sheds some light on it.
 

twocyclemania

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Re: 1961 Scotty 3.6 cooling problem

mrcrabs: I just reviewed the diagram of the lower unit and it gave me food for thought. There are two positions where the 'appendage' from the wobbler type impeller can go. I'm wondering if I placed it in the wrong one? I'm going to open up the lower unit and place it in the other position. More fun since that gasket is a pain to make but I think I may have shot myself in the foot in where I installed it. Will let you know. thanks again
 

twocyclemania

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Re: 1961 Scotty 3.6 cooling problem

Well the mystery is solved. I moved the impeller 'appendage' to the slot in the middle and it's now putting out water like a firetruck. Can't believe I screwed up something as simple as that. Anyway, it's a lesson learned and should prove useful now that I have a few scott/firestone and related motors. Something you don't forget and something to keep in mind if someone else comes up with the same problem. Thanks everyone for the input.
 

1946Zephyr

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Re: 1961 Scotty 3.6 cooling problem

Good, now I would put your old impeller back in, since it looks good and test it out. If it tests out good, then keep your new one in your stash, until you actually need it. Those things are going to get hard to find, so a new one in your posession, ten years down the road will be nice.
 

twocyclemania

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Re: 1961 Scotty 3.6 cooling problem

1946 Zephyr: Not bad advice. Only I don't feel like opening it up again and dealing with the grease and making another gasket. I did keep the one that was in there and I smeared it with silicone grease and stored it in a baggie. It's nice and like you recommended; I'm going to keep it for the next job. Thanks for the advice!

ps Hoping I'll be here 10 years down the road if you know what I mean.
 
M

mrcrabs

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Re: 1961 Scotty 3.6 cooling problem

better yet buy another new one while there still around and grease it up and squirrel it away, :)
 
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