1963 Evinrude DuckTwin help

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metal249

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Anyone know the point and plug gaps for this engine. Both points have visibly different gaps. Any help is appreciated
 
JB

JB

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Re: 1963 Evinrude DuckTwin help

Those plugs should be Champion J4C, Metal. Many have been running J6C, which is okay, but J8C is too hot.

I agree with Coleman Kayak on the gaps.
 
1946Zephyr

1946Zephyr

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Re: 1963 Evinrude DuckTwin help

Actually that motor originally called for a J6J. The J6J is no longer in production, so I would go with a J6C.
 
JB

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Re: 1963 Evinrude DuckTwin help

1946Zephyr said:
Actually that motor originally called for a J6J. The J6J is no longer in production, so I would go with a J6C.
Click to expand...

I know there are lots of charts, etc that waffle back and forth between J4 and J6 and either will work. I used both in my Johnny JW and found the J6 better for trolling and the J4 better for cruising. There are charts that call for J8C, which is too hot.

My source is the 1964 edition of the Johnson Service Manual that lists the JW-18 (identical to the '63 Ducktwin).

1956 was the last year it is listed using J6J. Perhaps that is where you got the "original" notion. J6 is listed for 1952 through 1956. They changed to J4 in 1957. My Manual doesn't go past 1964, so I don't know when or if they changed back to J6.
 
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metal249

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Re: 1963 Evinrude DuckTwin help

Thanks guys, got it gapped and it runs great. New problem though, I ran it in a bucket and it is barely shooting water. It has four holes about halfwayup the shaft. two holes on one side spay a light mist and the holes on the other side just drip. Due to the spray on the one side, it seems to me the the impeller must be working. Can I run this in a mix of water and radiator flush to clean out the passages? Good idea or bad idea?
 
lindy46

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Re: 1963 Evinrude DuckTwin help

Have you changed the water pump impeller? You should have a healthy spray coming out both sides.
 
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metal249

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Re: 1963 Evinrude DuckTwin help

No I haven't. I tried the motor last year a couple of times and couldn't get it firing on both cylinders. The guy I bought it from claimed that he replaced the whole ignition, which he did, just not correctly(wrong gaps on everything and a disconnected point wire). It sat for the year, and now i'm messing with it again. I'm just going through all of it now that I have it running correctly. How hard is it to replace the impeller? Any other maintenance I should do?
 
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metal249

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Re: 1963 Evinrude DuckTwin help

So i've taken off the lower unit and flipped the motor upside down. I flushed the water tube with a spray gun solvent, and let it sit for a few minutes. I then tilted the motor back over and dumped a lot of black and brown crud out. I repeated this three times and finished with remington spray oil. I took apart the impeller housing, which looks fine, and cleaned everything. The shaft came out of the lower unit and I can't seem to get it back in. It looks likes the pinion gear that goes around the shaft is just floating around in there when I turn the prop, and I cant figure out how to get it lined up. Is there some trick I dont know, or is it just a pain in the ***?
 
lindy46

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Re: 1963 Evinrude DuckTwin help

Easy job - just remove the lower unit by removing the 4 bolts which hold it on. The lower will drop right down. The water pump housing sits on top of the lower unit. Remove the cover (I think 2 or 3 bolts hold it on) and the impeller sits inside. Slide the cover/impeller off the top of the driveshaft and replace the impeller. Make sure there is an o-ring in the groove on the top of the driveshaft. When you put the new impeller in, make sure it engages in the pin on the driveshaft - that pin is what turns the impeller with the shaft. Put a little grease on the splines on the top of the driveshaft, and re-mount the lower unit, making sure the copper water tube slips into the rubber grommet in the pump housing. Replace the lower unit bolts and you're ready to go. It may take a little maneuvering to get the driveshaft to seat in the crank, so be patient. It may be necessary to rotate the shaft a little to get the splines to line up.
 
lindy46

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Re: 1963 Evinrude DuckTwin help

metal249 said:
The shaft came out of the lower unit and I can't seem to get it back in. It looks likes the pinion gear that goes around the shaft is just floating around in there when I turn the prop, and I cant figure out how to get it lined up. Is there some trick I dont know, or is it just a pain in the ***?
Click to expand...

Sometimes a pain to get back in. Try laying the lower on its' side and see if it slips back in. Just takes patience. Make sure you REPLACE that impeller, even if it looks good.
 
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metal249

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Re: 1963 Evinrude DuckTwin help

Just put it back together, I gained a little more flow, but not much. I'm going to take it down again and put in a new impeller. If that doesn't work then I'll pull the cylinder head to see if its blocked. Thanks guys for all your knowledge. I will post results.
 
coleman kayak1

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Re: 1963 Evinrude DuckTwin help

My 64 lightwin hardly flows any, just a light spray at WOT, most of it goes out the exhaust. I have never had an overheating problem and just put in a new impeller. Sounds normal to me.
 
1946Zephyr

1946Zephyr

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Re: 1963 Evinrude DuckTwin help

I would run it and see how warm the head gets. If it gets too hot, then I would check the other water passages, such as below the powerhead, where it attaches to the midesection in the water jackets, once the head is removed. I have actually had salt water motors that were completely blocked, because they weren't flushed, from the last trip to the coast.
 
Chinewalker

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Re: 1963 Evinrude DuckTwin help

Regardless of how it "looks" - replace the impeller. Then you'll know it's new and won't have to worry about it... On those 3s it is about as easy as it gets and takes all of 10 minutes to do...
 
nwcove

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Re: 1963 Evinrude DuckTwin help

if you are testing in a small barrel or bucket, sometimes the turbulance, and exhaust gas bubbles will make your motor not pump at its best, after you replace the pump, if it acts the same, try removing the prop while testing, just be careful not to over rev the motor.
 
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metal249

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Re: 1963 Evinrude DuckTwin help

Trying to remove the cylinder head right now. I took off the six bolts, broke the two middle bolts. I cant get the head off, It even runs with all the bolts out of it. VERY frustrating.
 
coleman kayak1

coleman kayak1

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Re: 1963 Evinrude DuckTwin help

Place a block of wood on the side of the head and tap lightly is what I would do. Just be careful to not damage anything. Let us know what you find.
 
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