Still Wrestling with 1969 55hp Problem

[rdh2059]

I posted on this a while ago, and the thread ended after receiving info to rebuild carbs again. <br /><br />Some history.<br />3 carbs rebuilt with new internal parts twice now. All carbs were tanked for 2 hours each, then blown out with air, then sprayed out with carb cleaner through every orifice and opening, then air again. Carbs then reinstalled and syncronized using manual directions.<br /><br />* New wiring harness.<br />* New fuel pump.<br />* Lower unit removed, new solenoid assy installed and reassembled - filled with OMC type C fluid.<br />* All fuel and vaccuum hoses replaced with new ones of same diameter as old. <br />* Compression 122psi per cylinder in all 3 cylinders.<br />* New rectifier.<br />* New 6 gallon fuel tank.<br />* New tank to motor fuel line.<br />* New Champion plugs.<br />* New Thermostat and gaskets.<br />* Prop 13x19 reconditioned.<br /><br />Here's the problem description:<br />Motor idles perfectly - very smooth clear down to about 500rpm (yes set to 700rpm). When accelerating, motor works normally to about half throttle. When I push throttle over half way (on the water btw), motor kicks then slows down. Squeezing bulb on fuel line from tank does nothing. Holding the choke switch makes it run at full throttle, but way below what I think normal power should be and not up to WOT rpms. <br /><br />I've run it at half throttle for over an hour and then did a spark plug check. All 3 plugs look identical - very mild browning of insulation, with normal faint oil residue on plugs. Spark test indicates at nearly half inch spark jump on each cylinder. <br /><br />What else could it be? I've checked fuel and pretty much replaced everything involved. I've rebuilt carbs twice, but no difference. Motor charges nicely and has hot spark. <br /><br />Any more ideas?<br /><br />Also someone mentioned a way to convert this CD type ignition over to the car type coil and condenser type. Can someone give me detailed instructions or at least a link as to how to do this? <br /><br />Thanks,<br />Rick

 

[chuckz]

Re: Still Wrestling with 1969 55hp Problem

Have you checked the timing and the timing advance?

 

[Laddies]

Re: Still Wrestling with 1969 55hp Problem

Ck the timer, rotor and anti-reversing wire on the crank, it sounds like some thing is shorting out as you advance the throttle, also ch the 2 wires that come out of the timer arm--Bob

 

[JB]

Re: Still Wrestling with 1969 55hp Problem

"Holding the choke switch makes it run at full throttle, but way below what I think normal power should be and not up to WOT rpms."<br /><br />Not enough fuel (you seem to have covered that one) or too much air to at least one cylinder.<br /><br />Primary suspects: leaky gasket at carb, intake manifold, reed plate or bypass cover(s).<br /><br />If they are all okay, look for anyplace air can get into the crankcase without going through the carb throats.<br /><br />Just a note: It is ALWAYS faster and cheaper to find the cause of the trouble before throwing parts at it.

 

[rdh2059]

Re: Still Wrestling with 1969 55hp Problem

I purchased this motor knowing it was going to require a lot of work. Fixing it is still by far cheaper than buying a new motor in this hp range. <br /><br />The wire bundle had so much broken insulation that it was a wonder anything electronic worked at all. Thats why it was replaced. <br /><br />The fuel pump spit fuel out the back side of the pump, indicating the diaphram was bad. I replaced it rather than rebuilt it because the pump was quite old and new one was readily available.<br /><br />Rectifier was burned out and required replacement. <br /><br />Spark plugs are a standard tune up item.<br /><br />Old fuel tank was rusted steel one, so replaced it and a new hose as a standard system upgrade. <br /><br />The thermostat was missing from this motor so I inserted a new thermostat and gaskets in it. A motor that runs too cold is hard on the motor too.<br /><br />The motor would not shift out of forward, so I took the lower unit apart, replaced the water pump housing due to wear and the impeller. The solenoids were not working, so in taking the shaft apart, the lower threaded part twisted apart rather than unthreaded. The only way to repair this is to have someone custom make the shaft or replace the entire solenoid assembly<br />, which I did. Now the motor shifts perfectly. <br /><br />Every piece I replaced was replaced for real reasons, not simply replaced due to "when all else fails replace components" mentality. <br /><br /><br />The timing is the one thing I haven't checked. The linkage to the timing plate is calibrated per manual directions, but I haven't checked the timing yet. If the timing was retarded, wouldn't the motor backfire or run rough? It never backfires, per se, just kicks as it slows down.

 

[ross_trucking2002]

Re: Still Wrestling with 1969 55hp Problem

Rick, I write this note to you, since I have and run a 1969 Johnson 55HP 3CYL.. Model 55ES 69A.. I just wondered if you are using Champion Plugs #UL 77 V ? I have almost completely rebulit mine from pistons, rings, wiring harness (from scratch), stater coils, amplifier, etc.. Mine is currently working fairly well, on my 16ft Starcraft at nearly 40mph at 5000 rpm. I have learned to realize, that this motor is quite different than other Johnson motors, and it has taken me a while ( almost 2 years ) to get it working as well as it does now.. This motor seems to be very fussy about spark, timing, etc. I think we may have to talk more.. Ross

 

[JB]

Re: Still Wrestling with 1969 55hp Problem

Getting it to run at WOT by engaging the choke categorically eliminates ignition as a cause and categorically identifies fuel/air mix as the culprit.<br /><br />Jeez, some guys would recommend a heart bypass for a broken leg. <br /><br />It is good to know that most of the new stuff was to fix identified troubles not related to the WOT problem. It would have been better to know it before. <br /><br />Good luck finding the air leak.

 

[fireman57]

Re: Still Wrestling with 1969 55hp Problem

JB, I don't know why but I have found my posts lately to be a little bitter and short tempered. I guess maybe that comes from suggestions not taken. I am not singling out this post by any means but it will be a week or so before someone will take a suggestion and do it. The suggestions cost the person nothing and will eliminate either spark or fuel but the people seemed "fixed" on something they heard from someone and believe that it the problem. Maybe they just someone to agree with them. It also might have something to do with being damn close to turning 50.

 

[JB]

Re: Still Wrestling with 1969 55hp Problem

Been there, Fireman.<br /><br />This time of year there are so many posts to look at and so many questions to give advice about that it becomes stressful sometimes and when advice gets ignored or contradicted it is annoying.<br /><br />Comes with the territory, I guess. We all get a bit impatient when our attempts to help are neither acknowledged nor followed.<br /><br />Turning 50 does make one less patient. Turning 70 makes us real bears.

 

[fireman57]

Re: Still Wrestling with 1969 55hp Problem

JB, I hope I make it that far. Rick Hall please do not think that I am singling you out. When I read this thread it just hit me what has been happening lately. No offense meant to you.

 

[rdh2059]

Re: Still Wrestling with 1969 55hp Problem

No offense taken. I'm 46 and pushing the curmudgeon thing pretty hard myself. That's why it wasn't easy for me to give in and actually ask some questions...;-) God forbid that I admit there's something I can't do or figure out...! LOL! <br /><br />As a followup. I've checked for intake leaks with a smoke generator and found no air leaks. I'm nearly positive its a timing thing, but we'll find out soon. I took the boat (and motor) to a local outboard repair shop. I don't want to tinker with this all summer trying to get the most out of it on my own. Once its fixed, I'll post what the problem really was and certainly won't forget what it was myself...;-) The motor has a ton of potential on the old 16 foot boat I'm using it on... <br /><br />Rick

 

[REELSPORT]

Re: Still Wrestling with 1969 55hp Problem

To change from a cd amplifier to a coil on this motor is a simple matter. Remove cd amplifier and coil. Use a 12 volt low resister coil that is pre 70s one that is used with points. The hot wire going to the amplifier connects to the positive side of the coil. Next the wire coming from the points connects to the negative side of the coil along with a condenser. A resister should be mounted to the block and a wire run from the negative side of coil to the resister. Should you not know what a resister is you can most likely find one at your local junk yard it is the ceramic looking block most likely mounted to the fire wall on most cars with points. Finally you will need to make you a coil wire to run from your distrubter to the coil. I used the coil wire off the coil I took off the motor and cut it close to the coil because one end needs to have the screw that screws into the distributor and the other end you will need to make up to fit the coil. Once this is done you are ready to check your spark and head to the water.

 

[REELSPORT]

Re: Still Wrestling with 1969 55hp Problem

I forgot to tell you that I have this same motor and was not getting enough spark with the amplifier and considering the cost of a new amplifier over $300.00 I changed to a coil and condenser and the motor runs better now than it has since I have had it.

 

[JB]

Re: Still Wrestling with 1969 55hp Problem

Well, I give up but I have to ask.<br /><br />What is the theory that engaging the choke changes the behavior of the ignition? Everyone (but me) seems to think this points to a weak spark problem.<br /><br />I fail to see how enriching the mixture compensates for a weak spark and fails to kill the engine. <br /><br />What is it that I don't know here?

 

[Basscat 1]

Re: Still Wrestling with 1969 55hp Problem

JB, I hear you.<br />Just like you said before, "Jeez, some guys would recommend a heart bypass for a broken leg."

 

[REELSPORT]

Re: Still Wrestling with 1969 55hp Problem

No jb if you read the thread he asked how to convert from the cd amplifier to a coil and condenser and I was just answering his question

 

[JB]

Re: Still Wrestling with 1969 55hp Problem

AHA!! Makes sense now, Reelsport. <br /><br />There were two questions and I think he expects converting the ignition to correct his mixture problem.

 

[rdh2059]

Re: Still Wrestling with 1969 55hp Problem

Give me some credit please... I asked two somewhat unrelated questions with different answers. Reelsport stated that he had converted his motor (of the same type) to a coil, and condenser type ignition. This particular motor is notorious for ignition problems. My particular motor does not give symptoms of ignition problems at this time, but sooner or later the cd ignition component will go out and I want to be ready to replace it with a standard type. <br /><br />So No I do not think the coil and condenser will fix a fuel mixture problem. Yes, I was asking about both, but with all the flak I have received about this, I have said to hell with it and took it to a outboard repair place that I trust. I think this problem is related to timing, but don't know enough about the timing on this specific engine to do it myself. <br /><br />That's it. Someone close this thread and I'll post a result once I get the bad news from the repair mechanic...<br /><br />Rick

 

[JB]

Re: Still Wrestling with 1969 55hp Problem

"I'm nearly positive its a timing thing, but we'll find out soon."<br /><br />I guess I misunderstood you, dennis.<br /><br />Sometimes I wonder why I bother.