69 johnson 55hp stalls when over 1/3 way to wot

[1969johnson55]

ok so i bought this boat this year ( first mistake) guy said runs fine just out on it momorial day no problem (big lie) motor blows at loading ramp first time putting in the water spark plug was removed . so i replace powerhead with used one off ebay also re did water pump it was totaly gone set points to .010 sinked all used same carbs well when i get out to lake boat starts but runs ruff when i try to accelerate it stalls at 1/2 throttle well i bring home reset points to .012 because even tho they were used they still looked like brand new set lowspeed needles they were out way far like almost 2 turns book says 5/8 turn out i also checked compression test all 120-122 and added fule pressure gauge so i go back to lake boat starts and idles way better but only about 1/4 throttle before it stalls well while at lake i reajusted low needles to very rich boat gets over 1/2 throttle and plains out but still stalls at wide open throttle and wont idle but fuel presure stays good so i reed other post and and i guess it is high side of carbs so i took apart cant find nothing wrong tho they look like brand new inside i used flash light to look at high jets look fine blow air thru all holes nothing appers to be cloged just to be safe i ordered kits for all three i am going to let set in carb cleaner over night tuesday i will have kits i have alraedy got it apart so a am going to do it but after looking at carbs i dont think they are the problem any help would be much apreciated i would like to do somthing with this boat other than (Breaking Out Another Thousand ) i have already done that

 

[Phyreman]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

I was experiencing a similar issue. What I found was that the motor was seriously out of time and first worked on that, then made sure that the mechanical advance stop was correct and locked down. I have a 60ESL71C so much is similar. I have dual points in mine, not sure if you do, but I also recommend just a dab of blue lock-tite for your points to prevent slippage during engine vibration. Also did everything else you mentioned and all is good. But check your spark advance.

 

[1969johnson55]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

ok looked at book on the advance stop it says i need tach, timing light, test wheel, and tank. i was wondering can i do this in the water i do not have a test wheel and the book said i needed one but does not tell which one for that year. also i do not have a tach which i wanted to get anyways can i use a regular tack set to 6cly since 4 cycle v6 fires 3 times per rev and 2cycle 3 cyl also fires 3 times per rev would this be ok. also book said need it to go to 4500 rpm i dont think mine is hitting that high of rpm now

 

[1969johnson55]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

ok i got the three kits for the carbs i have let all three sit it carb cleaner over night any last words of advice before i put them back together. oh ya i didnt remove plugs and lead shot should i do this?

 

[mrjohn]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

May want to check you spark plug! If you are running too cold you can bog down at WOT, but will idle and start fine.

 

[Tim Frank]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

ok i got the three kits for the carbs i have let all three sit it carb cleaner over night any last words of advice before i put them back together. oh ya i didnt remove plugs and lead shot should i do this?

Leave the lead shot, but you may as well pop plugs and make sure there is no problem in behind them. Way easier to do now than have to do it later...
My recommendation would be to absolutely remove the high speed jets and make sure that they are not constricted by build-up.
A #_ drill should go through...don't remember the size but someone in here will.

Great motors but the ignition is fussy and I would not have set the points to 0.012....stick with 0.010....IMO.

 

[Tim Frank]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

What plugs are you running?

 

[1969johnson55]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

What plugs are you running?

ngk b8h s plug stock plug should be champion L-19v. I dont know if the plug i got is hotter or colder tho i just replaced with the same ones the old powerhead had in it.

 

[Tim Frank]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

NGK???

"Skipper, I think I sees your problem." :facepalm:

Dump those, they are not an equivalent.
I don't know where you got the Champion number either....it's incorrect.
If you run at high speed for long stretches and need the surface gap plug....use L76V...otherwise L77JC4....gap at 0.030"

 

[1969johnson55]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

I got the l19v from a parts break down on boats . Net. I see on here tho l76v is modern replacement for l19v plug so i will pick up some l76v at the parts store tonight will let you know how this works out.

 

[Phyreman]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

Also, if you do need to check your timing, don't use use in-line cables, use induction (the kind that clamps outside the spark plug wires). If you use in line, the is a possibility of frying your electrics.

 

[Phyreman]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

Now I may need to double check MY plugs too.

 

[Tim Frank]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

I got the l19v from a parts break down on boats . Net. I see on here tho l76v is modern replacement for l19v plug so i will pick up some l76v at the parts store tonight will let you know how this works out.

I had the same motor for 30+ years, and the last 15 were the best ~ after I switched to the L77JC4s....

 

[194269]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

I was working at OMC when your engine was built, they were bulit with L-19V's the L-76V's came out a couple of years later. The right seting for the points on that engine is .010. Timing and clean high speed jets are most of the high speed running problems for outboards. Just my .03 worth, good luck.

 

[1969johnson55]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

ok i got it back together and same thing now i am running l76v plugs carbs just rebult today i also noticed while trolling was running little ruff and then clear for like half a second could i be losing spark at higher rpm mabey amp going out does anyone know how to check a amp?

 

[194269]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

Check your Distributor cap and rotor under the flywheel, The cap may have carbon tracks which will cause miss firing of the cylinders. If the cap is bad, new ones are expensive and replace the rotor. Also check for plug wires for shorting out against the block. Good Luck.

 

[1969johnson55]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

ok now i plan on resetig points to .010 and checking cap and rotor if i knew how to check amplifier i would but as of this far i dont

 

[1969johnson55]

Re: 69 johnson 55hp stalls when over 1/3 way to wot

so i think i an going to put new cdi control on it and see if that fixes it will let u know