Old Evinrude Yachtwin 4 information

[rich_]

I have acquired a Yachtwin 4 hp which I intend to get running and I think could be from the early 1970s serial number is 4036 E C 78082?

I am not familiar with the controls on this engine and have no manual or anything for it. what are the knobs on the front for? They both adjust from lean to rich (see attached photo) one high speed the other low speed, and how should they be set? They are both connected to the carb', the choke is self explanatory.

There's a lever on the side which I assume is the throttle because there's no twist grip on the tiller, it is marked "stop" "start" & "fast" but I can't see any way to disengage the drive or put it in neutral, because even in the stop position the prop shaft still turns when the starter pull chord is used.

 

[RogersJetboat454]

Re: Old Evinrude Yachtwin 4 information

Welcome to Iboats.

The number 4036 comes up as a 1970 4 horse here;
http://shop.evinrude.com/media/document/ModelNumberReference.pdf

Adjusting the mixture is usually done while running the engine under load, and adjusting it till it runs its best. When I do that I usually open it a hair more to the rich end to keep the motor from getting too lean.

Sounds like yours is direct drive with no gears. You start it in gear, and if you want to reverse, you simply spin the motor around backward so the prop is pushing water under the boat.

Make sure the impeller is replaced to keep it cool, and you may want to look here;
http://forums.iboats.com/engine-fre...kening-sleeping-outboard-boatbuoy-158086.html

 

[colbyt]

Re: Old Evinrude Yachtwin 4 information

Don't know about the 70 but the 69 used a cork float in the carb. The good news is you can buy a kit with a modern one for less than $20. The hi Lo carb needles can be hard to find but they are still out there. May not need those.

I would leave the knobs as are and try to start it. I can look up the start point settings for you if they need adjusting.

Check your compression and for spark before you you roll out the parts cannon.

 

[rich_]

Re: Old Evinrude Yachtwin 4 information

What should the compression reading be out of interest?

 

[nwcove]

Re: Old Evinrude Yachtwin 4 information

60 psi in both holes would be ok for that little motor. and they should be within 15% of each other. it will run with lower #,s but will be hard to start and wont idle well.

 

[Rick.]

Re: Old Evinrude Yachtwin 4 information

http://forums.iboats.com/engine-fre...sorted-carb-variations-joe-reeves-167352.html
This might help with your low/high speed needles. Great little motor you've got. Best of luck.

 

[rich_]

Re: Old Evinrude Yachtwin 4 information

thanks again for that information

 

[TN-25]

Re: Old Evinrude Yachtwin 4 information

Rich, all old manuals 1996 & prior are avallable here. They may have an original, as they did for my 1976 Johnson, or they may produce a clear photostat from the original file. If you are patient, I could get around to scanning and e-mailing my 1971 Evinrude Owner's Manual. The 1971 is the same motor as yours except for the decal on the cowl.

 

[rich_]

Re: Old Evinrude Yachtwin 4 information

Thanks for that offer TN-25. I am in the UK and the old owners manuals seem hard to get hold of. I have found some schematic drawings of the motor on line which have been useful but I'll message you an email address. Even just the bits from the manual you think would be most useful would be good enough rather than you have to scan the lot.

Rick, the link for the needle settings is of great help as I have removed them while dismantling the carburettor .

I was a bit reluctant to take this motor when I was offered it as it has no prop the starting chord wouldn't recoil ,which I've now fixed and no one could tell me when it had last ran . I only have basic mechanical knowledge and have never worked on an outboard before but the engine seems in good order, everything I've dismantled so far has not been corroded or had any bolts or screws seized. there was no spark to the lower cylinder but I switched coils over and the problem transferred to the other cylinder which I assume means it's a coil fault. I'm going to replace both any way because they look shot , all cracked and bits falling off them. The points look like new, and I stripped the carb' down this morning and it too looks pristine inside,the jets, the cork float and everything were it perfect shape and seemed to be operating as intended.

When I get the new coils it will be time to try to start it before spending any more money on it, I don't have access to a fuel tank to fit the connector , is it possible to rig a makeshift fuel supply to the carb, bypassing the fuel line connection on the motor?

 

[Rick.]

Re: Old Evinrude Yachtwin 4 information

Make shift connection should be to the pump, not the carb.IMO. Rick.

 

[rich_]

Re: Old Evinrude Yachtwin 4 information

That makes sense, thanks Rick ! Presumably via the pipe that goes into the pump from the fuel tank connector?

How does that fuel pump work? Is it a mechanical pump or Is it a diaphragm to control fuel supply on demand which works by vacuum similar to what japanese motorcycles used on their fuel taps. The vacuum pressure used to open the diaphragm when the engine was running and relax it to shut it off when stopped, It looks similar. On the older Brit' bikes you had to shut the fuel tap off manually or the carbs could flood when the engine was off particularly if the float needle hadn't seated properly or the spring was worn on the primer? Is there a way to prime the fuel pump to fill the float chamber or does it do this its self?