1996 Johnson 60hp 2 stroke not getting to full speed at random times

[Scotty K]

I have a 1996ish Johnson 60hp. At random times it will barely go. Typical max speed is about 30mph. When it's acting up, I go about 6 or 7 mph.

Sometimes when it is going slow, it will all of a sudden take off to full speed. It never happens the opposite way where when I am going full speed and it slows way down.

Any thoughts or opinions are welcome.

 

[racerone]

Nobody can see , touch or hear tour motor.-----Provide accurate information.-----Does spark jump a gap of 3/8" on each lead?----Test this at more than 1 throttle position , as there could be a broken wire.----Water pump impeller replaced every 5 years?-----Post actual results of a compression test.-----Use a STRONG flashlight and look into carburetor bores when testing.-----Compare amount of fuel coming up the nozzles.

 

[Scotty K]

Thanks racerone for getting me started here.

Spark plug jump 3/8 gap?
Top cylinder - yes
middle cylinder - no
Bottom cylinder - yes

I had checked for just spark (not the 3/8) yesterday and it was fine. Today I have no spark through over the 3/8 gap or even just on the spark plug. So maybe a loose wire that sometimes gets juice?

Water impeller replaced every 5 years?
I've owned it for 15 years and never touched it. Not sure about prior to that.

Compression test
Top cylinder 121
Middle cylinder 120
Bottom cylinder 124

Did not look at carburetor bores yet.

 

[airshot]

Gotta have accurate test numbers or we are just guessing ! Could also be a combination of things gone wrong....that is why you are ask for specific numbers.

 

[racerone]

Running on 2 of 3 cylinders explains it.----Need to install a new water pump impeller.----Or at least test your overheat horn.

 

[Scotty K]

Still playing with this thing. Yesterday, I switched the top spark plug, spark plug wire and coil with the middle spark plug, wire and coil. Still no spark in the middle cylinder so I assumed that the spark plug, wire and coil are not the issue. Is that correct?

Today I took the power pack off and inspected connectors and wires and where it bolts in. Everything looked good. No corrosion.

After putting everything back together, I checked the spark again. Working on all 3 cylinders now.

Did I accidently fix it?
Maybe power pack got jarred and made everything temporarily work but it is going to quit working at some random future time?

 

[Scotty K]

Just got done tinkering and I'm back to middle cylinder having no spark. Frustrating

 

[Mc Tool]

Hard to say wether its fixed or not coz we didnt find out what was wrong .
Its possible that by moving the wiring you have jiggled a loose connection . The only way to get it sorted is to go thru the harness untill you find it . A multimeter is invaluable here.
Start with any plugs you disconnected , look for corrosion ,loose socket/pins in the plug.
I would pull all the plugs and connectors ( maybe not all at the same time ) give em a squirt of wd40ish stuff and reconnect disconnect a few times , can scrape off corrosion and get things going again .
You can do this 2 ways , methodically with a digital multimeter and find the actual fault , or just clean/spray/wiggle everything in sight and hope for the best.

 

[Crosbyman]

either the coil is not firing or being fired or the sparks do not reach the plug

do a good ohms test to grd on the plug wire(es) and compare things.
things break or corrode

 

[Scotty K]

The powerpack has 3 wires coming out of it with each of the wires going to the 3 coils. Would switching the wires tell me anything? Would it be safe to do?

 

[Mc Tool]

The powerpack has 3 wires coming out of it with each of the wires going to the 3 coils. Would switching the wires tell me anything? Would it be safe to do?

Yep ,you have already proven the coil is ok when you swapped it over and the fault stayed in the same cyl, so take the power pack wire off faulty cyl coil and fit to one of the other coils (that did work ) and crank to check for spark on that coil and if there is no spark you gotta think the power pack is crook ,or if your real lucky might be the plug connecting the coil.
By swapping the power pack wires about the coils you will be able to prove the coils and the power pack. The timing will be well out and the engine wont run but all we are interested in is wether you have spark on each cyl or not .
Id be lookin at that power pack with some suspicion . Have a good look at it as you may see something obvious .

 

[cyclops222]

deleted

 

[Scotty K]

Yep ,you have already proven the coil is ok when you swapped it over and the fault stayed in the same cyl, so take the power pack wire off faulty cyl coil and fit to one of the other coils (that did work ) and crank to check for spark on that coil and if there is no spark you gotta think the power pack is crook ,or if your real lucky might be the plug connecting the coil.
By swapping the power pack wires about the coils you will be able to prove the coils and the power pack. The timing will be well out and the engine wont run but all we are interested in is wether you have spark on each cyl or not .
Id be lookin at that power pack with some suspicion . Have a good look at it as you may see something obvious .

I switched the wires going from the powerpack to the coils. Switched top wire to middle coil (which didn't work) to the top coil. When I do that the top cylinder is now without spark and the middle cylinder has spark. I must be tired because I can't think this through. Does that prove the powerpack is defective?

 

[Mc Tool]

I switched the wires going from the powerpack to the coils. Switched top wire to middle coil (which didn't work) to the top coil. When I do that the top cylinder is now without spark and the middle cylinder has spark. I must be tired because I can't think this through. Does that prove the powerpack is defective?

Yes , I think so . If all the coils spark when connected to the top or bottom cyl wires from the power pack and none spark when connected to the middle cyl wire from power pack , this tells you that all the coils are good (because they all work when connected to a good top or bottom power pack wire ) and that the middle cyl wire from the power pack is not working ( because none of the known good coils will spark when connected to it ).
Trace that middle cyl wire back to the power pack .....right inside if you can and make sure there are no breaks in the wire, other than that I think its time to get another power pack