18hp Johnson still will not start

[yam350yfm]

My 1957 fd-11k 18hp still will not start. Here is where it is at:
1. New coils
2. New condensers
3. New points (could be the problem, not holding gap at .024)
4. New plugs gapped at .030 (Champion 4 series)
5. Rebuilt pressure tank
6. All new gas hose on pressure tank and engine

The motor pulls through and backfired a couple of times. Checked for spark and have spark, checked gas and have fuel to the carb, checked that the correct plug wire is on the correct cylinder. Pulled the plugs and dried them off after about 12 to 15 pulls. Tried the following:
1. Throttle at "Start", choke on (backfire puff of smoke, then nothing for a while followed by gas leaking from carb, assume flooded)
2. After dry out of plugs and tried same without choke, no backfire, no smoke
3. Choke on, motor in gear, half throttle, nothing
4. Same as #3 with full throttle, nothing
5. Same as #3 or #4 without choke, nothing

Also noticed that the "fast" and "slow" speed settings seem to do nothing, and may not be working at all. The knobs turn but the springs do not move. I also noticed through the flywheel window when re-checking the points that they were not holding a consistent gap, were anywhere from .019 to .028, not sure the window is always in the exact spot, or if this is a problem with the points or how they were installed.

Anybody with any suggestions before I end up taking it to a shop?

 

[CATransplant]

Re: 18hp Johnson still will not start

I don't see a carb cleaning and kitting on your list. You've done everything else. Did you skip that?

Here's my suggestion: leave the fuel tank disconnected, and no fuel in the carbs. Spray premix into the carb venturi and pull. It should fire up and run briefly. If so, pull the carb and clean it properly, as described in the sticky at the top of this section of the forum.

If not, then it's time to recheck your ignition work. Did you torque the flywheel nut to the recommended specification? If not, you may have a sheared flywheel key. That will cause backfiring at a minimum and complete non-start at worst.

But, if you haven't cleaned the carburetor and installed a carburetor kit in your previous work, I'd sure go ahead and do that.

 

[tashasdaddy]

Re: 18hp Johnson still will not start

this is courtesy of Joe Reeves.

(High Speed Adjustments)
At full throttle, with the proper size screwdriver, slowly start turning one of the H/S needles in segments of 1/8 turn, waiting momentarily for the engine to respond, then repeat turning. You will reach a point where the engine will start to die out. At that point, back that needle valve out approximately 1/4 turn. Now, go to the other High Speed needle valve and repeat that procedure. At some point in that 1/4 turn out, you will find the smoothest high speed setting (you can now lower the throttle rpm). That will have both high speed needle valves set correctly, and at that point you can lift that center lever adjustment of that high ridge, keeping it lifted until the point is facing the engine, then lower it into its proper position. (When you turn that lever now, you're adjusting both High Speed needle valves at the same time

(Slow Speed Adjustments)
Now, lowering the rpms of course, take the engine out of gear and set the throttle just to where the engine will stay running. Again, in segments of 1/8 turn, slowly start turning in one of the slow speed needle valves, waiting a few seconds between each turning for the engine to respond. As you turn the s/speed needles in, the rpms will increase..... and as it does, lower the rpms to where the engine will just stay running (otherwise the rpms will climb quite high). You will reach a point whereas the engine will either start to die out or it will spit back (sounds like a mjild backfire). At that point, back the needle valve out 1/4 turn. Repeat the process with the remaining slow speed needle. Again, at some point in that 1/4 turn out, you will find the smoothest setting. When finished, tighten the jam nut somewhat, then remove and reinstall the s/speed knobs correctly (right side up).

 

[jbjennings]

Re: 18hp Johnson still will not start

Don't take that thing to a shop! You CAN whip it and save yourself some gas money! I've had a motor or two that had plug wire ends that were corroded badly inside the wire where the coil fits over them that I had to snip off about a 1/2 inch, pull a little slack, and reinstall the coil on. Don't forget that the wire with the brass clip on it goes on the top plug. Also, your pts. should be gapped at .020 don't forget to check the wire ends inside the plug end for the same problem. I like Cattransplant's idea of squirting fuel in the carb throat and seeing if it will bust off for a few seconds. I try that one regularly when I'm suspecting spark problems. This may not be the best way, but I've found that when my spark is set right I can hold a plug in one hand and rotate the flywheel by hand and if it's right the plug will give you a small jolt. And I mean turning it by hand, not the rope because the rope will knock the blankety blank out of you if hold the plug. If the spark is working right, 3/4 of a turn should pop you. Cleaning the carb is easy, just make sure you blow out all the passages really good. I believe you need 45lbs. of torque on that flywheel nut. Your nuts on the idle and high speed jets should be adjusted so that the knobs only turn if you WANT them to turn. that adjustment procedure from Joe Reeves works every time, of course. THat's a really good 18 by the way, and one of the sharpest looking to me.

Oh, I reread your last post---if your plugs are wet with fuel but it's not starting, it's definitely a spark problem....
Hope you get it running,
JBJ

 

[yam350yfm]

Re: 18hp Johnson still will not start

The fuel tank was completely cleaned and new 91 octane with 24:1 synthetic and some Sea Foam added, so the gas was purchased right before we tried to start it. As for carb cleaning all that consisted of was some STP carb cleaner sprayed into where it could be without taking the carb apart, then blowing it out with a air compressor while slowly turning the motor through. I could feel the compressed air pulsating out the exhaust port in the LU as the starter rope was pulled slowly. I do have a rebuild kit ready if I have to do that, just was really hoping not to have to go there! The carb cleaning was done a week or so prior to the attempt to start the motor.

The flywheel was torqued to 45 foot pounds with a new Craftsman torque wrench. That was the torque setting the manual specified.

For the high / low speed settings the screws were turned in all the way, then the high speed was backed out 1 turn (to the left) and the low speed was backed out 1.5 turns to the left. Honestly all that those screws seem to do is hold the high / low speed knobs in place, unless I am turning the wrong thing. There are springs between the carb and face plate and those do not appear to compress, or un-compress in relation to turning the screws. The springs are on the outside of the tube that goes from the carb to the knob, and the screw is in the center of the knob, if that description makes sense.

I still have 105 psi in each cylinder with the compression tester, so compression does not appear to be a problem.

The motor was in a 50 gallon can with water about 1/2 way up the leg. Oh, and I have a new impeller too, so that it should pump water.

All of the work has been done in stages. The motor had sat since 2004, then had to be un-seized which was done via PB Blaster and Sea Foam spray into the cylinders and removal of the intake covers (reinstalled with new gaskets). Then the compression tested good so the flywheel was pulled and found one coil was bad, explaining why one plug was clean and one was fouled. Replaced both coils, points, and condensers to know it was all new and when it was put in. Stickers inside the cover indicate tune-up work performed in 1988 and 1993, with only replacing one coil each time.

I can see spark when I remove the plugs and leave them in the plug wires while I pull it through. Just not sure if it is sparking too early or late based on the gap and what appears to be an issue with the consistency of the gap when it is open.

Anyway it has been the course of several months and I was really looking forward to that motor firing up. The latest setback prior to this was the transom top cracked because of some rot in the wood. so I am also performing the repair on that. Obviously I will not be on the water by the end of May, and am now shooting for mid-June.

CATransplant, tashasdaddy, and jbjennings, I thank all of you for your help, suggestions, and encouragement. The Wisconsin boating season is short enough without all of this happening.......if all else fails I can stick to really small lakes and get an electric trolling motor!

Here is what I will try tonight:
1. Shift to neutral (verified the prop does not turn in neutral, but does when in forward or reverse).
2. Put throttle in the "Start" position on the tiller handle
3. Pull choke out to full choke
4. Verify the high speed is 1 turn out, and low speed is 1.5 turns out
5. Verify plug gap at .030, reinstall plugs and plug wires
6. Verify plug gap at .020
7. Spray some premix into the carb
8. If it starts, connect the gas line, pump the tank and restart

If it does not start, time to rebuild the carb....a whole new adventure!

 

[CATransplant]

Re: 18hp Johnson still will not start

Spraying some stuff in the carb throat accomplishes nothing at all towards cleaning the carburetor, as good as it feels to do it.

I have no doubt whatsoever that a disassembly, soak, blowing out of all orifices, and reassembly with the new parts from your carburetor kit will solve this final problem for you.

It's not that big a deal to do. While it's apart, you'll also be able to inspect those mixture needles and assess the threads where they go. It sounds like your problems are in the carburetor, based on the other stuff you've done.

Now, take care of that, and you'll probably be able to go boating. Check your manual for complete instructions on a carb overhaul and follow them. Buy a bucket of carb cleaner with a basket, and go for it.

 

[tmcalavy]

Re: 18hp Johnson still will not start

First address the point gap problem, it should hold a .018 or .020 gap and throw a fat, blue spark on both wires. Torque the flywheel down correctly. To anchor the knobs on the needles/jets, remove the knob and reset the lower needle (high speed) to 3/4 turn out from lightly seated...then reseat/reset the upper needle to 1 and 1/2 turns out. Reinstall the knobs/dials so the pointer is at 12 o'clock on high speed and 6 o'clock on the slow speed. Tighten the knob screws tightly but don't crank them down...you sometimes have to hold the needle with a pliers or something else to anchor the knobs tightly/correctly. If it dumps gas out of the carb when you squeeze the primer bulb firm, you need to pull the carb, diassemble, clean it...especially the float bowl, reassemble and reinstall. Here's how I cold start my 57 FD-11: shifter in N, throttle handle cranked over to Fast, choke out, primer bulb firm...three pulls or so and it comes to life, let it run and then ease the choke in/off. Let it warm up, and away you go. When its warm, barely one pull and it comes to life. Sounds like your carb is dirty enough that the needle settings aren't doing much. After you get it running, you'll have to adjust the high and low speed needles on the water/boat just a little. Let us know how it goes.

 

[wbeaton]

Re: 18hp Johnson still will not start

Good advice so far. I'll add that the springs are only to hold the face plate out against the cowl and have no bearing on carb adjustments.

The start mark on the tiller handle is only a guess on that motor. With the engine in neutral, turn the handle as far out toward fast as it will go. Then pull out the choke and pull it over.

Although I don't agree with your carb cleaning technique you at least know its getting fuel to the motor. Perhaps too much. Whenever you suspect the motor is flooded, try starting with the choke in and the fuel line disconnected. Sometimes it takes a few pulls, but the motor should start if it has good spark.

 

[yam350yfm]

Re: 18hp Johnson still will not start

tmcalavy, thanks for that input. I will try to start it as you recommend. If it does not fire, then I will have to rebuild the carb. I have the kit from iboats:
HP Year Sierra
18 1957-1968 18-7043

I was planning to decarb after it was running, but if I have to pull the carb for cleaning and rebuild, I will. The Seloc Outboard tune-up and repair manual should have the instructions.

Thanks again!

 

[tashasdaddy]

Re: 18hp Johnson still will not start

it is a very simple carb. just needs to be clean. and good gaskets. then use the carb settings above.

 

[tmcalavy]

Re: 18hp Johnson still will not start

It's a pretty simple carb, but best to work on a clean bench/table with newspapers etc. Go slowly, pay attention to how it comes apart and you should have no problem. There may be old gas crud in the bowl, which will affect the float. Definitely run some sea foam in its next drink of gas. The throttle band that indicates Fast, Start and Slow is rarely accurate after so many years...just a way to guestimate as has been pointed out.

 

[yam350yfm]

Re: 18hp Johnson still will not start

Well, it was still a no-go. Fuel leaking from the bowl area tells me the seals are dry and should be rebuilt for safe operation. I checked the Seloc manual and instructions related to the Type I carb and confirmed a rebuild is in order. I was looking at how the high / low settings should work and believe that is where some of the problem exists.

I reset the points to .020 and they seem to be holding that gap for both sets, so that was good news. Nice blue spark from both plugs, so once the carb is sorted out then I should be good to go.

I have the rebuild kit and the manual....only 32 steps.....what could possibly go wrong????

 

[mchin]

Re: 18hp Johnson still will not start

lots of great advice, have you tried switching the spark plug wire just as a test. The only reason I ask is that it was mentioned that the brass clip wire needs to be on top, but I have run into motors where the previous owner didn't follow that rule and the motor behaved just like yours, till I switched the right wires with the right cylinder.

 

[yam350yfm]

Re: 18hp Johnson still will not start

Actually the plug wires were reversed when we first tried to start it and noticed that during troubleshooting. We tried to start it one more time last night before pulling the carb and it still will not fire. I was advised not to try starting fluid, so I have avoided that. I looked at the carb rebuilt procedure again and I will have only 30 steps as step 1 is disconnect the battery and step 32 is reconnect the battery. As this is not electric start, those don't apply.....heck at this rate the thing will rebuild itself!

One other odd thing. We have probably made in excess of 100 pulls on the rope start in attempt to start it. I have noticed that after a period of time in the water that there is a substance that looks kind of like a black worn out scotch brite pad, about 1 to 2 inches in size. They are floating on the top of the water. Not sure if something was pulled into the lower unit at some point, or if a mouse got in there during the 4 years the motor sat in the boat house......