58 Johnson 18hp Carb Kit Question

[Seemer]

OK - I got the carb kit for my 1958 Johnson 18 hp FD-12. Now, when I took the thing apart these are the pieces I expected to replace:

Gasket between carb and engine
Gasket between top and bottom halves of carb
Packing for low speed adjust (pain to scrape out)
Packing for high speed adjust (pain to scrape out)
Float and related parts

When I got the kit it contained:

Gasket between carb and engine
Gasket between top and bottom halves of carb
Float and related parts
Then the various pieces in the pic below...but with no instructions

Which do I use for low/high speed packing? What are all the other bits for? I know the brass rod is for the float - got that covered. Also, the silver cap is for the area to be drilled out - although the diameter is too small to fit so I will not do that. What about the other pieces? Extras? Am I missing other areas in the carb?

Many thanks for your help.

Regards.

 

[Barnacle_Bill]

Re: 58 Johnson 18hp Carb Kit Question

It is common to include a few extra parts in a kit so they will fit other carbs other than just one. Just use the parts that pertain to your carb.

 

[rjezuit]

Re: 58 Johnson 18hp Carb Kit Question

I believe the red one goes under the needle housing. The thick one on the carb center post. The packings go on the hi/lo speed needles.

 

[Seemer]

Re: 58 Johnson 18hp Carb Kit Question

Sorry guys - this doesn't help much. I suspect that someone else had messed with the carb before so the only parts that came out were the packing (mesh washers) around the high and low needles and two larger gaskets (carb to engine and the one in between the two halves of the carb. Here are some pictures with notations and questions. The question is which parts from the carb kit (see pic in first post above) get used where. THANKS

 

[rjezuit]

Re: 58 Johnson 18hp Carb Kit Question

The fat cork looking one goes over the brass center tube. It gets sandwiched between the top of the carb and the bowl. The red one goes under the float "nut" The silver thing that unscrewed on the needle is supposed to come out. The packing goes on the needle valves. Rick
http://www.duckworksmagazine.com/03/r/columns/max/10/index.htm
http://www.duckworksmagazine.com/06/columns/max/index10.htm

 

[lindy46]

Re: 58 Johnson 18hp Carb Kit Question

In pic #4, nothing goes in that hole - just screw the main nozzle into the hole and put the fat cork washer on last. As mentioned, it seals the top to the float bowl. The clear nylon packing goes in last and butts up against the packing nut. Should be two of them. The threaded metal sleeve which the low speed needle screws into will tighten up with the packing nut.

 

[Seemer]

Re: 58 Johnson 18hp Carb Kit Question

Thanks guys. Last question. The fat cork piece that goes over brass jet and between top and bottom of the bowl....when I put it in place, the two halves don't seat against eachother...there's now a gap. Do I just compress it down as I tighten the screws in?

 

[lindy46]

Re: 58 Johnson 18hp Carb Kit Question

Thanks guys. Last question. The fat cork piece that goes over brass jet and between top and bottom of the bowl....when I put it in place, the two halves don't seat against eachother...there's now a gap. Do I just compress it down as I tighten the screws in?

Yes.

 

[Seemer]

Re: 58 Johnson 18hp Carb Kit Question

great. thanks

 

[Seemer]

Re: 58 Johnson 18hp Carb Kit Question

OK - I finally had some time to rebuild the carb and reinstall to the engine. She did fire on my third pull, but then not again. There still is some fuel leaking from I believe the low speed needle....or the chamber below the low speed needle? Is that possible? Also, the air silencer that bolts onto the front of the carb...should there be a gasket between the face of the carb and that thing? Don't currently have one. The leaking fuel is dripping from the bottom of the air silencer thing and coming from between where the face of the carb meets the silencer thing.

Also, when I pump the fuel from the tank do I pump until the button will no longer push? Maybe I am over flooding the carb? I was pushing it in until it wouldn't push anymore.

Thanks.

 

[JSGOLD]

Re: 58 Johnson 18hp Carb Kit Question

No need for a gasket for the silencer. Sounds like you did flood it, and the leakage from the needle is probably the "packing" washers. The aftermarket ones are fiber, the original ones were a little more pliable. I ended up replacing mine with OEM ones but ohers here have been able to use them OK. My motor is only 5.5 but these are similar in design so I have a pretty good idea of what your are dealing with. Might check, maybe yours needs 2,3 or even 4 washers per jet. Possibly tighten the nuts a little more. Getting the adjustment so it starts OK is important. On mine I adjausted the jets one turn each and was able to adjust but yours might need a little more......good luck.


On the pump, I found on mine I pump until I get a fair amount of resistance but not until I can't pump any more.....

 

[lindy46]

Re: 58 Johnson 18hp Carb Kit Question

Float may not be adjusted properly. I usually run the motor before I put the silencer on so I can see if there are any leaks and where.

 

[Seemer]

Re: 58 Johnson 18hp Carb Kit Question

Yippie!! She's running....in neutral. Now have to play around with the slow speed needle to fine tune the idle and get ready to put her in gear.

I just needed to pump the tank button like 3-4 times instead of until totally firm, then keep the throttle open and quickly adjust low speed needle to keep it running. For whatever reason, she wouldn't start with the choke open.

Of course my shoulder hurts now.....