140 johnson v-4

[xltier]

i am posting this for my neighbor.his boat running on the muffs is missing off and on -on the #3 cylinder.we have cleaned out the carbs and installed kits.they were clean already.new plugs,fresh gas.then he borrowed power packs from a repair shop and it does exactly the same thing.hes thinking about ordering a stator.my thinking is the stator would effect all cylinders the same.i was leaning towards the timer.does anybody agree with that or have any other ideas.thanks

 

[R.Johnson]

Re: 140 johnson v-4

Changing part's is not the way to trouble an engine. Is the engine sound to begin with? Determine that first with a compression test.

 

[xltier]

Re: 140 johnson v-4-missing a little

Re: 140 johnson v-4-missing a little

the compression is 145-148-150-150.being a auto mechanic for 35 years has taught me that throwing parts at a job is very expensive.thou i have a fully equipped 2 bay shop for 22 years i still havent purchased the test tools for a johnson outboard.i do have the proper tools for a bellows job on a mercruiser thou.anyway thats why i thought i could get some pointers on here.the motor seems as thou its been well cared for and very clean and rust free.[mostly]thank for any help offered.

 

[sprdty]

Re: 140 johnson v-4

what year is it?
i have a manual for a 1978 or 79 series motor, i will make sure.

its just sitting in abox if this is your year let me know & i will send it to some one that could use it.

 

[xltier]

Re: 140 johnson v-4

it is a 1979-thanks

 

[sprdty]

Re: 140 johnson v-4

the manual is a 1978

 

[emdsapmgr]

Re: 140 johnson v-4

Try switching the coils and see if the problem moves. A peak-reading voltmeter is really helpful when troubleshooting outboards, esp for the stator and timer base. Try putting a timing light on each plug wire when running the engine. Look for strong, constant flashes, or misfires, or weak flashes, etc.

 

[xltier]

Re: 140 johnson v-4

with the timing light #3 isnt as steady as the rest.

 

[tashasdaddy]

Re: 140 johnson v-4

i agree total swapping the coil with one of the others is an easy troubleshooting method. 5 minutes, if the problem follows the coil, replace the coil, if not then we test for more. here's test, there are 6 pages here so flip thru, to find your engine.

http://www.boatpartstore.com/page28.asp

 

[xltier]

Re: 140 johnson v-4

its being difficult.first its good ,then its not.is-aint.hard to test that way.tried swapping coils and new pack.i think a timer would be in order.doesnt the stator effect all cylinders equallly??

 

[R.Johnson]

Re: 140 johnson v-4

Here's a case where a running test with a peak reading volt meter would be in order, charge coil, sensor's , pulse pak. It would point right to the problem. That meter can be pricey, but so are those component's.

 

[outdoorsman71]

Re: 140 johnson v-4

the manual is a 1978

I am new to forum read your posting that you have a manual that may be helpful to me . I have a 78 140hp johnson seahorse...recently developed a problem shifting F-N-R cable is moving now but still wont go in to reverse even with cable unhooked. Anyway may be in lower unit and could use a manual on it . How much for yours?

 

[xltier]

Re: 140 johnson v-4

the book was offered to me by a another poster.

 

[jjohnson1984]

Re: 140 johnson v-4

hi' just joined forum and am an owner of a 84' johnson 140 myself. I had the exact problem it seems your describing my engine ran fine at idle for awhile when problem first started, but wold miss at around 1800 rpm. i was advised that the powerpacks or even the coils but everything checked out. i switched sides or powerpacks and coils around properly and still the problem persisted on the number three cylinder. it didn't follow the coils or pwerp's. the problem ended up being the timer base it seems that with the years one the retaining screw down clips had worked itself free and the timr base was worn on theinside someting maybe due to disalignment or even overheating prior to my ownership of it. unfortunately the timer base is expensive something around $450 bucks original johnson parts and not availale through any aftermarket i know of. But your best bet is to find the part locally at a salvage yard or used part retailer. check the inside of timer for scuffs to insulation and refuse any that show wear through insulator. the only part of the insulator that should be exposed is the two contacts thatit has on the inside. hope this helps. and dont forget to properly torque the flywheel once you have finished your repair to avoid any damage to timer or stator due to misalignment. post rply if this helps

 

[emdsapmgr]

Re: 140 johnson v-4

The only way to troubleshoot the ignition system is from the OEM manual. There are ohm and voltage output tests for both the stator and timer base. What have you found from the tests suggested in the electrical system chapter?