'58 FD-12 Super Lean

[Big Jay]

Starting a new thread here guys... Hope that's Ok:redface:... lol

I've cleaned and reinstalled the carb on this engine replacing the packing washers only. The float was good and the float needle seems fine, doesn't stick and is not grooved so I kept it. The packing however, came out in pieces. I've cleaned and adjusted the points, and spark is jumping 1/4" on the tester. Compression is 118 and 120 cold and dry.

That said, I've had it out twice now. First time out, I had the needles at the recommended starting points and man was she rough. Took several pulls to start and coughed and coughed. Managed to get it to settle down only by turning out the slow-speed needle a good full turn to a turn and a half from the original 1.5 turns out. At 2.5 -3 turns out, she finally started sounding good. I then went to adjust the high-speed needle and at WOT she barely moved at all. Once again I started turning out the valve to enrich the mix and after about the same amount of turning out it picked up and eventually I had it running like a champ. Once it was as good as it was gonna get, I re-adjusted the slow-speed and I was good. But not really.
I burned a quarter tank of gas in 15 minutes at WOT that day.
Upon inspection, the top plug was healthy looking, normal according to all charts online. The bottom plug however is black and sooty. This tells me (correct me if I'm wrong please) the top cylinder is likely the culprit as it is running right at this heavy-rich mixture, and the bottom one isn't burning everything and is sooty because of it.
In another thread someone suggested I was running "over lean" due to a possible air leak and my needle-valve positions were compensating, and this sounds about right to me.

I went out tonight intending to do the carb cleaner test, but chickened out because I just don't know lol. So I went for a ride instead. The motor did start nicely (kicked 3rd pull and started 4th) It still coughed a lot at first then leveled out a bit once warmed up, still coughing at idle, but livable. The fuel consumption however, I cannot live with.

My question is this:

If it's an air leak I'm looking for, how do I find it? Is there a procedure to follow, some things I shouldn't do? Someone suggested using a carb cleaner and spraying the gaskets on the powerhead a little at a time waiting between each squirt to listen for changes in RPM (intake manifold gasket etc.). My concern with this is if the gasket isn't the problem, am I going to eat it enough with the cleaner to create a new problem?

I appreciate any input on this as I am running out of daylight in the evenings for testing as the season rolls on by without me lol.

 

[Daviet]

Re: '58 FD-12 Super Lean

What plugs are you running and what are they gapped at?
When you cleaned the carb, did you remove the core plug on top of the carb and clean the passages in there?

 

[Big Jay]

Re: '58 FD-12 Super Lean

I have new J6C's installed gapped at .030 and no....:redface: that was the other thing i didn't change out. I cleaned everything out real good mind you. But without an actual carb kit I had no welch plugs to replace the old ones.

Do you suppose this may be my problem? I'll pickup a kit tomorrow if you do.... I figured they'd be ok as long as I cleaned out the passages.

 

[Daviet]

Re: '58 FD-12 Super Lean

The passages under the core plug are the low speed circut, if they are not clean, you will not be able to adjust the carb properly.

 

[Big Jay]

Re: '58 FD-12 Super Lean

Hmm... now that you mention the welch plug you've got me thinking.

I guess it's possible the cleaner I used (J/E Engine Tuner) could have eaten the sealant on it away. I guess I should just go get the kit and try again with the right parts huh?

I will post my findings soon. Thanks so much Daviet, sometimes it takes someone to point out the obvious.

 

[Big Jay]

Re: '58 FD-12 Super Lean

The passages under the core plug are the low speed circut, if they are not clean, you will not be able to adjust the carb properly.

Sorry, didn't see your second reply til I posted again lol. If the passage isn't clean in the low speed circuit, would it effect the high speed one so dramatically?

And would it account for only one foul plug? These are likely silly questions but I really don't know :redface:

 

[jbjennings]

Re: '58 FD-12 Super Lean

Just my opinion:
You only have one carb for both cylinders. If one cylinder is running good, your carb is not the problem. You have bad spark on the bottom cylinder. Fix the spark problem and your motor will likely run good.
JBJ

 

[Big Jay]

Re: '58 FD-12 Super Lean

Ok... I'll check the spark again, could be something got bumped when I clean the inside of the engine compartment.

But my carb is running super rich, would it not be compensating for something?

Thanks for the replies guys, it all helps

 

[Big Jay]

Re: '58 FD-12 Super Lean

Alright...

I installed a carb kit (sans float) and made sure I had good spark on both plugs. Took it out tonight in the rain, and OMG it is still sneezing like an SOB lol... I have the high speed set beautifully at around 3/4 out with fantastic response, but the low speed is still 2 plus turns out from lightly seated and that's just to calm it down a little. I did however notice that it would stop sneezing altogether for a while (2 minutes) if I feathered down the throttle and run like it should. But as soon as I throttle up not in gear and let her down she immediately starts sneezing constantly for another 2 minutes or so.

Now, that said... I also noticed a leak in my dual fuel line connection right at the coupler at the engine, I can hear it hissing lightly when I shut down the motor. I can get it to stop by holding it a certain way but... it doesn't seem to help anything. Could it be my issue?

 

[HighTrim]

Re: '58 FD-12 Super Lean

Any air leak into the fuel circuit is not good.

You determined you have good spark, it will jump a 1/4" gap on an adjustable tester with a bright blue ZAP!!??

Comression is great.

Here is what you do. Wire the fuel tank directly to the carb, bypassing all connectors and such. Ensure the tank is good and the fuel line is not corroded or cracked. Put fasteners on all connections and ensure they are tight.

Let us know how it goes. If you no longer need to compensate for the lean condition you know what needs to be done.

 

[Big Jay]

Re: '58 FD-12 Super Lean

I am obviously going to fix the line leak asap, but I'm wondering if it is indeed causing my lean slow speed issues


The leak is on the fuel side of the couple btw

 

[Big Jay]

Re: '58 FD-12 Super Lean

Thanks HighTrim, I will do that right away and post my findings.

I sure hope it's that simple, I really love this engine

 

[Big Jay]

Re: '58 FD-12 Super Lean

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 yet to try connecting the fuel tank directly to the carb and intake as a trouble shooting alternative, simply because I haven't any more zip ties to reconnect the lines to the couplers afterward, I need to get into town to get some.

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: '58 FD-12 Super Lean

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 yet to try connecting the fuel tank directly to the carb and intake as a trouble shooting alternative, simply because I haven't any more zip ties to reconnect the lines to the couplers afterward, I need to get into town to get some.

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?

 

[kfa4303]

Re: '58 FD-12 Super Lean

Hi Big Jay. The procedure you're referring to is called a "Link n' Sync". There are several threads here in the forums that can walk you through the process. You may also want to double check the packings and washers in the Low speed needle. Here's a great link that can walk you through a carb rebuild. It's for a slightly different model, but all of the steps are the same. Be sure you're running at least 24:1 mix (5.5 fl. oz. of 2-stroke outboard oil to 1 US gallon of 87 octane gasoline) with Champion J4C or J6C plugs.

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

http://www.leeroysramblings.com/johnson_E-FD_15_18hp.html

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/377515/37751500001.htm

 

[Big Jay]

Re: '58 FD-12 Super Lean

Thanks kfa...

I am running J6C's BTW, I believe in following the manufacturer's recommendations when I can. Good call on the packing, I added 1 more felt and 1 more of the red/brown ones and it seems to have taken care of most of my sneezing issue . And it's a lot easier to tighten down the needle once in position, by far. Funny, OMC calls for just 2 packing washers for this model... I've got 5 .

Once I got the sneezing down, I was able to idle it down and set the LS to a more reasonable 1 1/4 turns out. I returned the throttle cam to it's original position and things seemed to be ok. I haven't had it on the lake yet, but so far so good...

What gets me is the Link n Sink. It says the roller should "just" touch and start moving at the mark on the cam... but... the roller never lifts off the cam, even at closed throttle. And at WOT, the butterfly valve is only about 90% open.

So... what to do next? There doesn't seem to be any other adjustment other than the slotted bolt hole on the cam and it's as far over (away from the roller) as it can go....

Suggestions?

 

[Big Jay]

Re: '58 FD-12 Super Lean

Any air leak into the fuel circuit is not good.

You determined you have good spark, it will jump a 1/4" gap on an adjustable tester with a bright blue ZAP!!??

Comression is great.

Here is what you do. Wire the fuel tank directly to the carb, bypassing all connectors and such. Ensure the tank is good and the fuel line is not corroded or cracked. Put fasteners on all connections and ensure they are tight.

Let us know how it goes. If you no longer need to compensate for the lean condition you know what needs to be done.

I have O-rings on order for the tank line coupler, it sucks living up north in that if things are back ordered... we wait the longest it seems

kfa's suggestion of the packing needing to be reviewed made sense to me. I was having a hard time tightening down the LS needle so I figured I'd try that first seeing as it involved way less than the direct tank line method.
However, if this proves to not take care of things, it's my next step in troubleshooting this issue.

Thank you for the suggestion

 

[nwcove]

Re: '58 FD-12 Super Lean

just curious, but what was done to the ignition system other than cleaning and setting the points? any visible wobble in the armature plate at idle??

 

[82rude]

Re: '58 FD-12 Super Lean

just curious, but what was done to the ignition system other than cleaning and setting the points? any visible wobble in the armature plate at idle??

original coils?new?original coils on a johnny that old will be toast.they may run a motor but can cause all kinds of grief.

 

[Big Jay]

Re: '58 FD-12 Super Lean

The coils had been changed by the PO and look brand new, condensers look new too but that probably doesn't mean much lol. The points look like they were replaced, but some time ago. They align perfectly and had some pitting that I filed smooth. The new ones I installed on my BigTwin 40 don't line up that well at all...

The surface of the powerhead had a thick film of oil/grease on it in places directly under the mag plate, so I disassembled it, cleaned it with engine tuner and all the components then reassembled making sure the points gap was at .020. The mag plate does move a bit side to side by hand, but it doesn't seem to move at all while running.

The 2 washers installed beneath each mounting screw on the coils for height still don't compute, but it certainly doesn't seem to be hurting anything lol. I figure the PO must've had a reason....