1956 Evinrude 3hp ("Duck Twin") Twin questions

[felixwankel88]

Hey, i have just picked up a 1956 evinrude 3hp twin boat motor.. it says duck twin on the back but havent been able to find much info on it.. i put new coils in it and cleaned the points and it runs like a champ..i did remove the impeller and still is very rubberry.. i did a compression test and i am geting 85 om both cylnders... what is bad?? what is like new?? what will it stop running at??.. also on the two fuel mix screws i have messed with them so much how much sould i turn them all way in and then out to get a ballpark... also is there any links to a part book with the part numbers and scematicks.. any abslootly any info on this motor would be awseome because you can never have to much info... one last question.. i have never taken it in the water and i have a 12 foot aluminum boat how fast should this motor get me going and what is the max Hp you can put on a 12ft boat safely....<br /><br />Thanx in advance for any help <br /><br /><br />Dustin

 

[TTravis]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

Felix,<br /><br />Check out my 3 HP project at http://www.outboard-boat-motor-repair.com Sounds like you already know a lot but you might enjoy seeing my project.<br /><br />That motor will push your boat along at 4 or 5 MPH, maybe 6. They were not designed to put your boat up on a plain. These little motors are designed to allow you to get to your fishing spot and back on a nice lazy day. I had mine out this past weekend pushing a boat that is not much bigger than a canoe.

 

[TTravis]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

85 PSI is about right for these motors. That is what I have with mine. Your motor won't run with anything less than about 65.

 

[Paul Moir]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

To set those little controls on the carburetor, follow Joe Reeves instructions: Click here.<br />85 would be pretty good in my books. I've seen them running on 55psi compression, but that's with my compression tester, using my methods. And probably being at sea-level helps too.<br />There's a few exploded diagrams at the Mastertech 3hp tuneup page but nothing takes the place of a service manual. Consider purchasing one or even just borrowing one from the local library.

 

[felixwankel88]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

Hey,tom thanks for the Great info... i have one other quick question.. what is the proper touqre of the flywheel<br /><br /><br />also i seen the duck twin add on your site, what is diffrent from the duck twin from the just normal 3hp twin??<br /><br /><br />Thanks again for the help.. anymore info on this engine or this motor would be Great.. like you say i can never have to much info<br /><br /><br />Thanx <br /><br /><br />Dustin

 

[Paul Moir]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

I've got that info handy:<br />40-45ft/lbs for the flywheel nut.<br />The difference between a ducktwin and a lightwin is the paint job.<br /><br />Do you have a model number? I don't see a '56 Ducktwin in '56:<br /> '56 Evinrude Catalog.

 

[felixwankel88]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

the serial number is 3020-02334 if there are other numbers u want tell me where to loook and ill tell ya<br /><br /><br />it may be possible i have the wrong year.. im really new at boats<br /><br /><br />Thanx again for all the help<br /><br /><br />Dustin

 

[Paul Moir]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

No, you've got it right. That number checks out as a '56 Ducktwin. I guess they just didn't put it in the catalog for some reason. Sorry about that!

 

[felixwankel88]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

also it has a J8 apposed to a J6 is that ok

 

[felixwankel88]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

opps thouse numbers are about the spark plugs

 

[Paul Moir]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

No, you need the J6C. J8 is too hot (unless you're at very high altitude?). Gap is .030"

 

[felixwankel88]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

im at one of the higest allitudes in my state which is MASS, but i will pick up some j6c for sure

 

[Paul Moir]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

You can 'read' the plugs. Run around at full throttle for a few minutes and then shut down the engine as quickly and safely as possible. Take out the spark plugs, and if they're lighter than tan they're too hot.<br /><br />We don't really have any altitude here so I'm not well versed on what steps to take for high altitude running.

 

[felixwankel88]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

one other quick question... i see alot of people change the head gasket.. even though mine has good compression should i change the head gasket??

 

[Paul Moir]

Re: 1956 Evinrude 3hp ("Duck Twin") Twin questions

No there's no need to change it unless you wanted to service something - get a look at the bores, clean the water jackets or something.<br />Back in the bad old days, you had to pull the head to clean off carbon build up. But nowadays with the correct mix (24:1) and using TC-W3 oil, all you ever have to do is to 'decarb' it with decarb spray occasionally. Details of that process are in the Engine FAQ Forum posted by roscoe.<br />Those little 3hp engines are great & reliable little runners. They just tweaked the design up into the eighties when they finally discontinued them (as a 4.5hp at that stage). It's amazing to see these 50 year old engines still putting in a regular day's work.