Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

[chippster]

I've set out to do a carburetor cleaning and gasket replacement. I was told that this motor has not run for 30 years and that was backed up by there not being a drop of gas in the carburetor or in any of the old hardened fuel lines attached to it. I really didn't see any build up of anything inside the carb except on the cork float. On the other hand, the gaskets are extremely dried out. And, I've got a few questions about these gaskets:

1. Both inboard needle packing gaskets that seat against metal has become stuck against the carb. The first packing gaskets came out easily. I've been taking a 1/16" drill bit and scraping at the gasket (using it as a scraper, not in a drill), after spraying wd-40 on it, in order to remove it. I just get little bits out, so it's a long process. Anyone have suggestions on how to get these gaskets out?

2. Attached is a photo of the little circular gaskets that came with my rebuild kit. I'm not sure which gaskets go to what. The six in the middle of the photo are the packing gaskets, yes? And I put a skinny gasket on the brass float valve screw and the big gray/brown gasket on the high speed nozzle. Is that correct? Also, the two black rubber circular cross section gaskets and the two metal star washers seem not to apply to my carb. The bigger metal plug is the correct one for my engine.

3. In outboard-boat-motor-repair carb rebuild article, the use of two gaskets against the engine is mentioned. There's only one appropriately sized gasket for my engine in the rebuild kit. I could cut a little larger diameter in the gasket opening in another gasket supplied with the kit if this is really a good idea. Any opinions on that out there?

View attachment 186228View attachment 186228

 

[nwcove]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

i usually just use a piece of sturdy copper wire bent into a small hook shape to pick out the sometimes stubborn packing washers., sounds and looks like you do have all the small gaskets in order. there should be no need to double up the gasket on the carb flange, ive never heard of it actually.

 

[HighTrim]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Looks like you have everything in order, except the circlip for the float needle. It is a thin wire shaped to attach to the float arm on one end, and hook around the detent in the needle on the other end. I see the needle, but not the clip. Do you still have it?

 

[chippster]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Yes, I still have that clip. I dumped all the rebuild kit contents into a little box when I started to do this task. At first I didn't notice it, though.

 

[HighTrim]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Goes like this

 

[chippster]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Oh thanks... I had a gnawing feeling that I didn't know what that clip was for. The drawing is perfect.

 

[HighTrim]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Your float will look a bit different, but you get the idea.

 

[chippster]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Got the high speed needle packing gaskets both out and still working on the low speed side innermost packing gasket. Read just a few minutes ago that it's possible to just put a packing gasket or two on top of the old ones when doing rebuilds, thus avoiding this problem. That would have been an easier way to do this rebuild.

At this point with the remaining old low speed gasket half removed, the surface is probably too rough and prone to air leaks to just put a couple of gaskets on top of it? And, with all my work of scraping away at the old gasket I'm sure I have put a lot of little bits of gasket into the low speed needle (edited, originally mistakenly wrote high speed) hole. Anyone know where the best place to blast air backwards through the low speed needle orifice would be? Where access to this high speed orifice is located on the carb is not readily apparent to me.

 

[HighTrim]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

I use a very tiny flat screwdriver, or dental picks. Should be able to pull it all out pretty quickly. Have you soaked it already>?] Does not have to be perfect, but most of the big chunks need to be cleaned up.

Bottom center of the bowl you will see where the high speed passage is.

 

[chippster]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

After a couple of weeks break, I am back at reassembling the carb.



The large high speed nozzle gasket seems like it is too thick. With the gasket in place the two halves are about 1/16" from meeting (with big gasket between halves in place) and since the gasket doesn't have a lot of "give" to it, a substantial amount of force would have to be applied to the screws in order to draw the halves together. Is this normal? The old gasket has half the vertical thickness, but it may have just been squished for so long that it collapsed down.

 

[nwcove]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

that is completely normal, and necessary for the carb to work. it wont take much force to pull the bowl up and get a good seal, just tighten from corner to corner a bit at a time. i would highly recommend getting a plastic float tho. "should" be brp part # 0396514 confirm before ordering tho.

 

[HighTrim]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Looks like a Sierra kit right? No float in that kit. I dont see the circlip installed on the float arm, dont forget it. Have you cleaned the carb yet?

 

[livinfulltilt]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Awesome, please keep up with the carb rebuild if you have time to do so. I plan on rebuilding my carb soon and this would be a great thread for me to follow! Thanks for taking the time to post this.

 

[lindy46]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Don't forget to remove the welch plug on top of the carb and clean the small holes underneath.

 

[chippster]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Here's a couple of useful links on carb rebuilding:
5.5 HP Evinrude Johnson 1954-1954 Carburetor Tune-Up Procedure
Carburetors

There's more on carburetors in the "top secret" files section, too. Plus I'm sure there are several old threads on this site.

I did order the wrong float. That's why you see the old cork float in the photo. I'm debating about ordering another float - the correct one mentioned by nwcove. Or, I am considering giving the old cork one a light sanding and a coating of super glue. The reason is, I bought this engine on-the-cheap because it has not been run in thirty years. And, I have purchased a bunch of parts for it but I want to see if it runs before I put too much more money into it. I have time to think about it because there is no rush. I don't have a boat yet anyways! Is this the definition of a burgeoning outboard motor addict?

 

[chippster]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Couple of more notes:

1) I did clean the carb. I was surprised to find that the carb was essentially clean. Using the word immaculate is almost not a stretch. It was still worth tearing the carb apart though because all the gaskets were fossilized - must have been installed a long time ago when dinosaurs still roamed the Earth.

2) I have read where others do not always take out the welch plugs. In my case, it was worth taking the plug out because underneath is where the low speed needle hole exits. And so that's where to shoot air to clean out the low speed needle threaded hole. I had accumulated a bunch of crud in there from digging out the packing gaskets. One note about that: the crown of the plug points upwards like a dome. Following advice from another post I started the re-install by lightly hitting a small socket that fit nicely around the plug. Then I used a prolly 3/8" socket extension and hit it a bit more firmly. Also, I put clear nail polish around the edge of the plug to help with the seal. I borrowed the nail polish!

 

[lindy46]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Couple of more notes:


2) I have read where others do not always take out the welch plugs. In my case, it was worth taking the plug out because underneath is where the low speed needle hole exits. And so that's where to shoot air to clean out the low speed needle threaded hole. I had accumulated a bunch of crud in there from digging out the packing gaskets. One note about that: the crown of the plug points upwards like a dome. Following advice from another post I started the re-install by lightly hitting a small socket that fit nicely around the plug. Then I used a prolly 3/8" socket extension and hit it a bit more firmly. Also, I put clear nail polish around the edge of the plug to help with the seal. I borrowed the nail polish!

IMO, a carb rebuild is not complete without removing the welch plug and cleaning the idle circuit.

 

[ronboonville]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

I would go ahead and get the new float and do the welch plug. It will give you peace of mind that you did it right. Also if have problems when you get it running you'll know its not the float or the small holes under that plug.

 

[chippster]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

Thanks, I needed the positive peer pressure. After hemming and hawing I did the right thing and ordered the carburetor float. The model number 0396514 float is the right one.

 

[chippster]

Re: Rebuilding 1956 Johnson 15hp FDE-10 Part 3: Carb Rebuild how-to's

The carb is re-installed. Thanks everyone!

Installed the new plastic float but kept the old cork one as a back up. It is actually in reasonably good shape for how old it is. Below is a photo of the carb with the new float and the little hold-down clip installed. The float's metal arm was bent a little in order to level it before reassembling the halves.