1969 20 hp. ALMOST leavs me stranded

[viciousfishes]

Hey guys,

I have a 68 20 hp johnson my grandpa gave to me and it was sitting in a barn for 30 years prior to him giving it to me. It used to run really well but recently its been suffering from sporatic power loss when its at full throttle. It never actually shut off though, it seems like its just running on one cylinder but then it will pic back up. Its really been stumping me. I want old faithful to live up to her name again!!

Any suggestions?

 

[HighTrim]

Re: 1969 20 hp. ALMOST leavs me stranded

What have you done to get her up and running? there is a thread in the Top Secret Files, the link after my name, about reviving motors that have been sitting. Would be wise to have a read. If they are the original coils, they will definately need to be replaced, along with the water pump, gear oil, plugs, fuel lines, and anything needed under the flywheel to complete the tune up, ie condensors, points, etc.... The carb will also likely need a cleaning and rebuild.

Let us know how it goes.

 

[tx1961whaler]

Re: 1969 20 hp. ALMOST leavs me stranded

It probably IS just running on one cylinder at times. Could be a number of things, from the spark plug, spark plug wires, coil going out when hot, dirty/misadjusted points, bad condenser, etc. I'd pull the flywheel to have a look.

 

[viciousfishes]

Re: 1969 20 hp. ALMOST leavs me stranded

I have replaced the gear oil and it seems to be cycling water just fine, and ive cleaned up the carb too. The coil sounds like a good idea ill definatly change that. But what does a condersor do?

 

[RogersJetboat454]

Re: 1969 20 hp. ALMOST leavs me stranded

The condenser is another name for a capacitor. It stores voltage on the primary side of the ignition. They should be dirt cheap to replace along with the impeller you should get too.

The engine may be cycling water fine, FOR NOW. But choosing not to replace the impeller before it breaks is risking your engine to overheating and possible damage. Rubber impellers don't last for ever, chances are your engines impeller is on borrowed time.
Help old faithful stay faithful!

 

[HighTrim]

Re: 1969 20 hp. ALMOST leavs me stranded

The condenser is another name for a capacitor. It stores voltage on the primary side of the ignition. They should be dirt cheap to replace along with the impeller you should get too.

The engine may be cycling water fine, FOR NOW. But choosing not to replace the impeller before it breaks is risking your engine to overheating and possible damage. Rubber impellers don't last for ever, chances are your engines impeller is on borrowed time.
Help old faithful stay faithful!

^^^^^What he said. Not even worth thinking about. The condensors dont typically fail like the coils do, but while I have the flywheel off, I change them, because as stated, they are dirt cheap. Pop the flywheel and you will know whether that coil is toast or not.

 

[sasto]

Re: 1969 20 hp. ALMOST leavs me stranded

there is a thread in the Top Secret Files, the link after my name, about reviving motors that have been sitting. Would be wise to have a read..

Nice, HighTrim.

Didn't know about the the proud dog owners thread. Guess he was a Master.

Thanks for posting it.

 

[viciousfishes]

Re: 1969 20 hp. ALMOST leavs me stranded

Thanks! That sounds like some crucial advice. I really appreciate the help yall... and so does my motor!

 

[tx1961whaler]

Re: 1969 20 hp. ALMOST leavs me stranded

All that stuff is available here at iboats. Nothing like being in the middle of the lake, with the wind blowing you away from the ramp to get you thinking "I wish I had spent that 25 bucks......"

 

[viciousfishes]

Re: 1969 20 hp. ALMOST leavs me stranded

Alright.. This is a list of things I have change:

Spark Plugs
All fuel lines
Oil line
Took apart fuel pump and inspected
Took apart carb and cleaned/inspected
New head gasket

And I think thats it. I took it out today thinking it would run like a champ, but I was wrong! I tried to take the flywheel off so I could look at all the components of the magneto system but I couldnt get the fly wheel off. It was stuck pretty good. Any ideas for getting it off?

 

[HighTrim]

Re: 1969 20 hp. ALMOST leavs me stranded

She will pop, they all do. You will need grade 8 bolts in your puller. Crank her down, small increments at a time, a few light raps with a hammer on the center bolt usuallly helps. Leave tension on overnight if you have to.

 

[jonesg]

Re: 1969 20 hp. ALMOST leavs me stranded

You will need,
2 new coils
2 spark plug wires with boots
2 point sets with capacitors
Carb rebuild kit
torque wrench to reinstall flywheel nut properly.
water pump impeller
seals for oil drain plugs

Don't lose track of which plug wire goes to which cyl.

 

[viciousfishes]

Re: 1969 20 hp. ALMOST leavs me stranded

If anyone is interested.. The problem was the coils. I just got off the water (what a nice day) and the boat ran the best it ever has. Thanks for the advice everyone! I wouldnt have been able to enjoy the day without yall

 

[RogersJetboat454]

Re: 1969 20 hp. ALMOST leavs me stranded

If anyone is interested.. The problem was the coils. I just got off the water (what a nice day) and the boat ran the best it ever has. Thanks for the advice everyone! I wouldnt have been able to enjoy the day without yall

Good deal!