Got my motor to fire, but ...

boatingbob

Petty Officer 3rd Class
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Aug 1, 2006
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I put new plugs in my 40 hp Johnson and it started right up and gets 28 mph, then I lost one cylinder, no spark, and it's not the plug. any ideas on how to fix this? please help!!!
 

KYHunter2

Chief Petty Officer
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Mar 20, 2006
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512
Re: Got my motor to fire, but ...

Well bob, theres several things that can cause the loss of spark.

I'd check all , grounds, wiring, plug wire, coil, etc.

You get the idea.

You'll need a manual , if you don't have one.

It shouldn't , be difficult to find your problem.

The trouble shooting procedures , in the manual, will get you there.

Bad grounds are often , the root of alot of problems.

I coat all the engine grounds with liquid tape after cleaning.

As well as all the electrical connections, that are exposed , even the solenoid and starter lugs.

And where the coils and heads meet, after bolting up, of course.

Good-Luck,

KYHunter
 

jtexas

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Oct 13, 2003
Messages
8,646
Re: Got my motor to fire, but ...

what year motor?

Switch the coil leads from the powerpack from #1 to #2 and vice versa then check spark again...if the same coil still refuses to fire then replace the coil. Otherwise...depends on type of ignition.
 

boatingbob

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Re: Got my motor to fire, but ...

jtexas said:
what year motor?

Switch the coil leads from the powerpack from #1 to #2 and vice versa then check spark again...if the same coil still refuses to fire then replace the coil. Otherwise...depends on type of ignition.

Umm it's a 1962, the plug wires go up under the recoil, The boat was working great until I shut it off at the dock then when I started it back up it would only run on 1 plug. I ordered a manual, it still hasn't arrived. Oh I also have a 1963 28 hp for parts would the ignition system on this be swapable to the 40?
 

KYHunter2

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Re: Got my motor to fire, but ...

There are some experts on these old motors on this site.

Paul Moir, being one of them, hopefully, they'll see your thread and respond.

KYHunter
 

boatingbob

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Re: Got my motor to fire, but ...

KYHunter2 said:
There are some experts on these old motors on this site.

Paul Moir, being one of them, hopefully, they'll see your thread and respond.

KYHunter
O.K. I'm gonna head out to work on the motor this morning, can anyone tell me if the ignition system parts on my 64 28hp are usable on my 62 40hp?
please help.
 

tmcalavy

Rear Admiral
Joined
Aug 29, 2001
Messages
4,005
Re: Got my motor to fire, but ...

Depends...on the size of the stator plate, flywheel, etc. Both are magneto ignitions, no electronics. Before you get into swapping, pull the top cover and maybe the recoil to gain access to flywheel. It may have a port in it so you can check/regap the points. Do that and see if spark returns. If not, time to pull the flywheel and check the connections...could be a bad or loose wire connection. Kinda sounds like that since it just dumped one cylinder/plug all of a sudden. You can pull the flywheel with a harmonic balancer puller from an auto parts store. Could also be a coil or bad points or bad condensor, only way to tell is pull the flywheel and take a look under there.
 

boatingbob

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Re: Got my motor to fire, but ...

tmcalavy said:
Depends...on the size of the stator plate, flywheel, etc. Both are magneto ignitions, no electronics. Before you get into swapping, pull the top cover and maybe the recoil to gain access to flywheel. It may have a port in it so you can check/regap the points. Do that and see if spark returns. If not, time to pull the flywheel and check the connections...could be a bad or loose wire connection. Kinda sounds like that since it just dumped one cylinder/plug all of a sudden. You can pull the flywheel with a harmonic balancer puller from an auto parts store. Could also be a coil or bad points or bad condensor, only way to tell is pull the flywheel and take a look under there.

K thanks I'll try that, first I'll start with the grounds and work my way in.
 

BoatBuoy

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May 29, 2004
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4,856
Re: Got my motor to fire, but ...

There should be 2 black kill wires that come from under the magneto. These wires, when shorted through the ignition switch, serve to kill the motor. Either one, if shorted to ground, will prevent it's respective cylinder from firing. I'd trace those wires to make sure the insulation is intact and the wires are not shorted anywhere.
 

Paul Moir

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Re: Got my motor to fire, but ...

Just a side note to the above advice, the entire stator plate, components and all should swap from the 28hp just fine. Also I would start with Boatbuoy's suggestions first since they're pretty easy to test and isolates the problem to under the flywheel.
 

boatingbob

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Re: Got my motor to fire, but ...

Paul said:
Just a side note to the above advice, the entire stator plate, components and all should swap from the 28hp just fine. Also I would start with Boatbuoy's suggestions first since they're pretty easy to test and isolates the problem to under the flywheel.

Well seems like my issues are under the fly wheel. I'm still waiting on my manual, Is the fly wheel placement directly related to the timing? like do I have to mark the shaft and fly wheel so I know where to put it back? I don't want to pull the flywheel and then have to worry about adjusting timing.
 

Paul Moir

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Re: Got my motor to fire, but ...

Timing is governed only by the point's gap, not the flywheel position. But flywheel position is important so it's been indexed to the crankshaft with a woodruff type key. There is no adjustment.

Have you got a puller that will work? I use the largest harmonic balancer puller I could find with three grade 8 1/4"-20tpi bolts:
6on6ko.jpg
 

F_R

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Jul 7, 2006
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28,226
Re: Got my motor to fire, but ...

Unless there is one of the small black wires shorted to ground, the flywheel has to come off and a systematic checkout made to find the bad component. There's no shortcut or magic involved.
 

boatingbob

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Re: Got my motor to fire, but ...

O.K. are all the bolts on johnson flywheels 1/4 20 tpi? I don't wanna mess up the threads, and if so how long should the bolts be? Also if I'm going to pull the flywheel should I just replace everything under there? if so what are all the parts I should order, I finally got confirmation of my manual being shipped. Any advice would be great. thanks
 

boatingbob

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Re: Got my motor to fire, but ...

boatingbob said:
O.K. are all the bolts on johnson flywheels 1/4 20 tpi? I don't wanna mess up the threads, and if so how long should the bolts be? Also if I'm going to pull the flywheel should I just replace everything under there? if so what are all the parts I should order, I finally got confirmation of my manual being shipped. Any advice would be great. thanks

Can anyone help?
 

Xcusme

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Apr 21, 2003
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Re: Got my motor to fire, but ...

Bob,
Buy 1/4-20 Grade 8 bolts approx. 4.5 inches. The 'parts' under the flywheel will be the point sets (2), condensers (2), and 2 coils. Inspect the coils for any cracks. Check and re-gap the points, per the manual.

If you had to replace everything mentioned, you'll spend approx. 75.00 depending on where you shop. The good folks here at iboats should have just about everything you'll need.
 

boatingbob

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Re: Got my motor to fire, but ...

Xcusme said:
Bob,
Buy 1/4-20 Grade 8 bolts approx. 4.5 inches. The 'parts' under the flywheel will be the point sets (2), condensers (2), and 2 coils. Inspect the coils for any cracks. Check and re-gap the points, per the manual.

If you had to replace everything mentioned, you'll spend approx. 75.00 depending on where you shop. The good folks here at iboats should have just about everything you'll need.

Thanks for the help
 

boatingbob

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Aug 1, 2006
Messages
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Re: Got my motor to fire, but ...

Found my ignition problem: looks like it had the original ignition system from the time it was made. fortunatly for me the 28hp I had has an all new ignition system so I swapped it over, unfortunatly the weather turned bad so I was unsable to test the boat today. the following picture was my old coils.

coil.gif
 
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