Johnson 150

[david901]

What would cause the timing to jump from 28 btdc to the opposite side of the flywheel that says #2 cyl while at idle.Timing light hooked up to #1 cyl.

 

[CharlieB]

Re: Johnson 150

Is the timing light flashing at BOTH 28 and 180 out?

That would indicate a bad ignition module.

More likely, what plug wire do you have the light connected to?

 

[david901]

Re: Johnson 150

#1 cylinder

 

[david901]

Re: Johnson 150

ignition coil or power pack

 

[Benny1963]

Re: Johnson 150

sheared key at flywheel possible check your top dead center
on #1 if its good possible pack prob hows it runnin .if it is it wont run long like that it should be popping and not starting 180 out

 

[david901]

Re: Johnson 150

it is just bogging down real bad! wouldnt a broke key make it jump all over the place instead of just 28 degrees and 180 out?

 

[david901]

Re: Johnson 150

any ideas. driving me crazy!

 

[Benny1963]

Re: Johnson 150

yes it wouldnt run ,probaly electrical get ya a factory manual and test stator and packs .theres a couple a guys on here who can help ya better
than i if key was sheared you wouldnt be going far .keep bumping up till someone comes along ,if not trouble shoot does your motor run seperate pack, or the single .will keep bumping ya ,up. do ya have a manual .
cdi has a free pdf files for testing ignition components are your carbs clean
put a timeing light on each cyl and look at light if you have a cyl that flashes intermitent then you will know its in your ign .sorry i couldnt help more
ive used new components on the three ive done ,check your plugs run your compression while ya have im out .

 

[Benny1963]

Re: Johnson 150

are ya on the top right plug,

 

[emdsapmgr]

Re: Johnson 150

What year model 150 do you have?

 

[CharlieB]

Re: Johnson 150

Replace the ignition module, or power pack as OMC called it.

Force used to run a blue box module that had a bad habit of 'crossfiring'. The box was SUPPOSED to fire two coils/cylinders alternately. When the box went bad it would fire one correctly and the other would double fire, once correctly and again as the first cylinder fired, making it appear as if the timing was changing from correct to 180 out.

The 180 out firing occurred during the intake stroke of that cyl, leaning the mixture such that the normal burn was lean and causing piston damage until total piston/cyl failure.

It is NOT a trigger, coil or spark plug.

Replace your ignition module and be glad that you found the problem early.