1958 Johnson FD-12 Starter Recoil Trouble

[Big Jay]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

The static setting of 1.5 turns out for the low and 3/4 for the high are just starting points. Usually fairly close though.

You may have an air leak, making the system over lean, and by turning out the needles you are compensating for that. Just a possibility. Check all connections and gaskets for leaks.

BTW, what manual told you 3/8 of a turn, a clymer or seloc? lol

This is the link to the manual I got the info from... it's an owners manual from the '57 18hp


http://boatinfo.no/lib/johnson/manuals/1957johnson18owner.html#/20

 

[Big Jay]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

What would I be looking for in a gasket leak?

 

[Big Jay]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

I just noticed cylinder no.2 plug is black with dry soot on it, and no.1 looks good though. I suppose that could be a hint, I should likely start my search around the bottom of the power head?

 

[Big Jay]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

So I've been advised by a friend that spraying small amounts of carb cleaner around the gaskets and listening for changes in RPM is a good way of pin-pointing gasket leaks.

Does this sound like a wise route? Is there a better less destructive way? I can't imagine the cleaner would do the gaskets any good, and would be hard to properly clean and remove from the powerhead.

 

[kfa4303]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

Hi Big Jay. Not sure what you mean by "gaskets"? Are you referring to the hi/lo speed needle packings? Either way, you never want to use starting fluid, or carb cleaner on a 2-stroke (unless of course you've taken the carb off to clean it.) Both are solvents that will strip oil off of the inner workings of the motor and increase friction and wear. Your carb settings do sound a bit off. Make sure you snug down the brass nut the needles pass through once you've got the needle dialed in. Here are some handy links for rebuilding and dialing in the carb. Make sure you're running the motor in a test tank with plenty of water too. Holler if you get stuck.

http://www.outboard-boat-motor-repa...hnson 5.5 HP 1954-1964 Carburetor Tune-UP.htm

http://forums.iboats.com/showthread.php?t=167352

 

[Big Jay]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

I was referring to the gasket seals on the powerhead....

The needles are both turned out 2.5 times-ish and I was told I likely have an air leak, so I'm trying to find out how to pin point it

She seams to be running "over-lean" as HighTrim put it, and that sounds right to me. With the needles so far out I must be burning/wasting a lot of fuel... and I wonder if I may do any damage to my engine by running it this way....

 

[Big Jay]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

With the needles at the initial settings as recommended in the links you gave me (thank you BTW), she sputters and kicks something fierce until the low speed is turned out another full time+. When at WOT, she lags and sits at about 1/2 rpm until I turn the high speed out a full turn+ and that's when she takes off, increases RPM and runs smooth.

Something ain't right lol

 

[Big Jay]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

I'm testing in the lake BTW

 

[64osby]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

Check all connections and gaskets for leaks.

from High Trim

If your using a pressure tank, you need to double check the o rings on the fittings, check the entire double hose for cracks, if you didn't replace the fuel lines on the motor check all those for cracks and good connections.

It would be better to replace all the lines, especially if you are using fuel with ethanol.

The packing at the needles is also a good place for an air leak.

If you go through all that and you still have an issue you might need to clean / rebuild the carb.

They are great motors and it sounds like your very close to running smooth.

 

[Big Jay]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

Alright, so I have rebuilt the carb with a proper kit including welch plugs, and replaced all fuel lines on the motor (not the tank lines however). This is what I've found:

1. The high speed needle is much closer to where it should be, and the WOT performance is great. Tons of jam .

2. It is still kicking like a mule at low speed however and the LS needle still needs to be way further out than the recommended setting in order to calm it. It then seems fine until I plane up then throttle down again causing it to go into a sneezing fit for a minute or so before I can feather the throttle down and calm it once again.

3. It seems to fluctuating as far as the plugs are concerned too. One day they both look great, the next day cyl. 2 is sooty, though you can't tell on the lake by it's performance that one plug is not firing right.


I have read on another thread (thank God for this site) about the throttle cam at the front of the mag plate timing the carb to the ignition. I looked up the setting for my motor and it seems to be way off.

Could this be my issue?

 

[Big Jay]

Re: 1958 Johnson FD-12 Starter Recoil Trouble

Ok, I may have placed this last post in the wrong thread...

I'll try re-posting in the other one.