76 johnson 135 only sparks the number 2 plug

hello i have a 1976 johnson 135 that i had on the lake it fell off the back of the trailer into lake sara. in the process of falling off of the trailer it landed at a 45-50 degree angle to the water and the motor was in the transport position. we decided she was ready to get wet so we fired her up and started going across the cove till it started loosing power but with our dock less than a hundered yards away we keeped on going till it finaly sounded like it was ideling on two cylinders (it was in the WOT position at this point] and then the motor cut out just feet from the dock. we roped it in and then tonight i took my timming gun out to test for spark and only the number two plug has spark. keep in mind that all the plugs are new. i got the boat for free off the bottem of the lake last year (old man launched it without a drain plug) and i want to know if it is worth fixing or putting back where i found her?

 

I had a brain fart and i bet i fould the plugs. i feel like an idot and how do i keep from doing so again? what are some tips and tricks to keeping one of these things going? and what fule/oil ratio do i need to run the old man told me 40-1 or 30-1 if its cold out is this true thats a bit of diference?

 

It sounds like that motor has had an eventful life. You should get hold of a manual, and follow the troubleshooting procedures therein.

 

Motor runs on 50:1 mix. Use higher quality, rather than cheap 2-stroke oil.

 

The first part you buy on a new (to you or otehr wise) boat is the appropate repair manual.



Run through the basic tune up and diagnosis procedures and replace all the consumables, before she makes you paddle home again.

 

I run my 115 at 60 to 1 with synthetic oil and 50 to 1 with mineral blend. And surface fire spark plugs. I can troll without oiling up. In your case I would get the manual as suggested and give it a good service. And give it a compression test before anything else, its no good doing anything else if the comp is down.

 

be careful with a 135 in the USA, they have a lot of compression.
Best fuel you can put in it.
Good idle is all about making sure it runs to temp and the carbs are synced to each other, thats easy as they should be shut at idle
uneven compression also makes for poor idle as does different float levels
For smooth idle use L77jc4 plugs but not for continuous WOT
if you want a real manual
https://www.outboardbooks.com/index.cfm/manual/135643/

 

Well i went out and replaced the plugs and only the number two would fire I tested the coils and all are working I took the trip wire from plug number two and used it to fire off coils 1 3 and 4 so the coils will fire they are just not being triped. What part off the motor trips the coils on these old things?

 

the power pak in the middle of the coils
its get triggered by 2 coils under the flywheel and the pak gets charged via 2 coils on the stator under the flywheel that also charges the battery.
You need a peak reading voltmeter to check any of this.
it has nothing to do with battery voltage or 12 volts.
Can you post a photo of he powerhead so we are sure its a 135
logic would say no spark on 3 cylinders says its the pack.

 

How do I test the power pack? It is a 135 the motor is labeled so I do believe

 

with your peak voltmeter you test the charge coil output coming out from under the flywheel, then the sensor coil output in the cable that moves when you advance the throttle ( also under the flywheel) and if thats not going out to the coils then you replace the pack
Cranking speed effects these readings, when checking the spark, were the plugs out?

 

The plugs where in I used a timing gun to check for spark

 

ok
pull the plugs and reconnect and ground them to ensure the coils are not open circuit and re test
Getting spark now points to a stator (or maybe sensor) coil issue.
in other words the capacitor not being charged up in the pak.

One word of warning assuming all the electrics are original and used you can end up replacing pak and stator ( maybe trigger) to get it to run right.

Stator and sensor/trigger easily tested with peak voltmeter or any multimeter with DVM/peak reading adapter
You can also do resistance checks ( if that fails you already have your answer)on all 4 coils, stator and sensor as they are only plain old coils as well although wound to do the job they do.
sensor measured in tenths of volts and stator in hundred of volts
no test for a pak only process of elimination other than output.

PS sensor (coil assembly) is the OMC word, Merc call it a trigger