How to convert 1964 Yachtwin to rubber fuel line?

LargemouthBass21

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I found a free 1964 Yachtwin 3hp on the side of the road last fall. It runs but only on full throttle (no idle/midrange) and I haven't been able to work on it since fall because Michigan :). I am planning on a carb rebuild among other things. I think the ignition, coils, points are ok because I am getting spark. It is not blue but it is there. I read somewhere that on these motors the color doesn't matter a whole lot. It has compression (haven't tested but can feel it when I pull it over). Anyway the fuel comes out the fuel line fine, but the threads on the connector are messed up or something where it hooks to the carb because it leaks steadily. Fortunately it doesnt leak at the fuel tank or petcock valve so I'm good there. I'm planning on Ethanol free gas only so it shouldn't matter but I'd really like to convert to a rubber fuel line. Is there a good way to do this?
The attached picture is what my connector looks like, except mine leaks a lot, has wonky threads, and the tip is bent.
Thanks everyone
 

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F_R

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The correct way would be to replace the shut-off valve and carburetor bowl with the 1965 parts 379686 valve and 379687 bowl if you can find them at a reasonable price.

Otherwise you maybe could drill and re-tap the carb bowl for a 1/8" NPT pipe thread and nipple. I dunno if that is possible though without looking up the specs for the inverted flare threads that are there now vs the specs for a 1/8" pipe thread drill.
 

LargemouthBass21

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The correct way would be to replace the shut-off valve and carburetor bowl with the 1965 parts 379686 valve and 379687 bowl if you can find them at a reasonable price.

Otherwise you maybe could drill and re-tap the carb bowl for a 1/8" NPT pipe thread and nipple. I dunno if that is possible though without looking up the specs for the inverted flare threads that are there now vs the specs for a 1/8" pipe thread drill.

so it appears that in 1965 they switched to rubber lines? Could I save money by just buying the bowl and cutting my line in the middle and then hooking it to a rubber fuel line and hooking that to the new bowl? Thanks!
About the drill and tap part I dont believe I have the parts for that...

EDIT: Cant find a bowl cheap enough, hard to do when my bowl is okay. All the metal fuel lines i see are disassembled and you have to put (weld??) the end flare things on yourself. I may try bending it back and using some sort of gas friendly gasket sealer on the threads but I'm just worried that'll gum up the carb when the gas eventually eats it away.
 
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Crosbyman

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I used a brake line from the auto shop… the pipe is flared at both end I cut it 2 inches long inverted it and reflared the back end that screws in the carb … the proper brake line tube has the exact threads used in carbs the short piece of brake line was JB welded at each end (outside the fitting and inside )
 

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LargemouthBass21

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I used a brake line from the auto shop… the pipe is flared at both end I cut it 2 inches long inverted it and reflared the back end that screws in the carb … the proper brake line tube has the exact threads used in carbs the short piece of brake line was JB welded at each end (outside the fitting and inside )

do you know what size the threads are? Thanks for the reply
Could this adapter work? https://www.basspro.com/shop/en/bass-pro-shops-barb-fuel-line-fittings
 

racerone

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The true test for spark on those uses a tester , not a spark plug.-----Your magneto is OK if the spark can jump a gap of 1/4" or more, does it ?
 

Crosbyman

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LargemouthBass21

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The true test for spark on those uses a tester , not a spark plug.-----Your magneto is OK if the spark can jump a gap of 1/4" or more, does it ?

I haven’t tested that yet but come spring I will try. I can get it to run full throttle (no idle or midrange) and it won’t start on the start position, the lever has to be all the way to full throttle to get it to run and stay running. I believe a carb rebuild is in order, I have all the parts but it’s too darn cold to work outside. I will try the jump a gap part in the spring but I did get spark off the block when I first found it. I installed a new impeller (old one cracked) and it still wouldn’t pump water but I think that was because the motor was at such an angle. The stand I was using was too short so I had the motor tilted all the way up. I am planning on a new stand and I think that will fix the problem. I know the pump works because I tested it in the water with a drill and got a good stream. Copper water line is also not plugged. I’m really really hoping the water jackets aren’t plugged because that will involve a lot of tearing it apart and looking for crud/blockage. Then I would have to buy new gaskets and such. My fingers are crossed the issue was just the water level and the angle of the motor. I can’t wait until warmer weather...
 

F_R

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Hey, I just checked the 1964 Yachtwin parts book and it shows it should already have a rubber gas line. Now the question arises what exactly do you actually have?

Edit: Update---it also shows a copper line kit. The mystery continues. BTW, the copper line version shows compression sleeve fittings, not inverted flare. Confused yet?
 
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LargemouthBass21

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Hey, I just checked the 1964 Yachtwin parts book and it shows it should already have a rubber gas line. Now the question arises what exactly do you actually have?

Edit: Update---it also shows a copper line kit. The mystery continues. BTW, the copper line version shows compression sleeve fittings, not inverted flare. Confused yet?

I will attach a pic in the next post down with my model number. I looked on evinrude and it shows model numbers with both “A” and “M” at the end. What do they stand for.

EDIT: I am showing the 1968 model no because that’s as far as it goes back. Mine is definitely older than that
 

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F_R

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The letter suffix at the end identifies a mid-year change---IF there was a change. Otherwise it means nothing.
 

todd281

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My '64 Yachtwin has the fuel line, and adapters to run it from the motor mounted tank, or a external floor tank .
 

LargemouthBass21

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Yup, it's a 1964.
3432C

Thanks! Out of curiosity, how do you tell that it’s a C?
EDIT: nevermind, I’m stupid. I thought the “C” was a “0” that got partly rubbed off. That clears it up, thanks everyone. Now if I could just fix the dang gas line...
 

LargemouthBass21

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My '64 Yachtwin has the fuel line, and adapters to run it from the motor mounted tank, or a external floor tank .

People talked about mid year changes to the models, perhaps yours is a changed one later on to improve the design? I know for sure that this metal one isn’t working too well. It doesn’t even have a gasket or anything
 

racerone

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The later years came with the port ready to install a fuel pump.----And of course the 68 models were the first to come with the separate tank.-------Some folks want the built in tank and some folks do not.----You just never know.
 
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