1979 Johnson 35hp lost spark

[ba_50]

Hi,

I did some ohms meter tests and it looks like the black/yellow wire from the key switch to the coil might be bad. The needle swung over when checking the resistance of the first two wires, but I can't check the wire going to the stator. My OEM manual doesn't say how to test the stator.

There is no spark from either coil wire. Thanks.

Do I need special equipment? Thanks.

 

[JUSTINTIME]

Re: 1979 Johnson 35hp lost spark

un plug the black/yellow that is the ermergancy stop switch

see if u get sparky

 

[ba_50]

Re: 1979 Johnson 35hp lost spark

Justintime,

I disconnected the black/yellow wire from the swith and never got a spark. The reason the wires didn't show a short on the meter is because I tested the wrong prong. I thought the "A" started on the left but it was the other side.

I found the stator test farther along in the manual and it checked out ok too. (I'm terrible on electronics and never could figure out Ohms meters. Getting better though.

Wish I had a neon tester for the power pack.

Maybe you can tell me why a rebuilt starter won't turn the flywheel fast enough the allow the pinion gear to drop down, with a like new battery? The person who worked on the starter told me it would drop down after it started, but I don't believe that as they don't always start on the first crank and they still drop down. Thanks.

 

[JUSTINTIME]

Re: 1979 Johnson 35hp lost spark

alright

it goes like this

stator sends power to power pack (CDI) then send to coils

so test stator with volts (u need a dva) and ohms
what did u get

Test triggers, the same way
what did u get

test coil inputs
what did u get

test coil ohms
primary
what did u get

only reason i told u to disconnect the emergency stop switch because if it was grounded out, u would get no spark

 

[ba_50]

Re: 1979 Johnson 35hp lost spark

Justintime,

A friend and I did all the Ohms tests listed in the OEM manual. The only one that failed was the charge coil. The needle was very close to zero and should have been 475 + or - 75. The tests included the sensor and chrage coils, coils, key switch, and stator.

I don't have a neon tester for the power pack and the others.

 

[JUSTINTIME]

Re: 1979 Johnson 35hp lost spark

the reading, did u make sure u were in the right setting
i personally do not like ohms, if it is hot or cold u get different readings

now u have a battery charge coil and a capacitor charge coil?

CCC is the stator which sends a/c to the CDI (POWER PACK) then CDI changes the a/c to d/c that gets sent to the coils

u really need to test volts to make sure u r not getting volts

 

[ba_50]

Re: 1979 Johnson 35hp lost spark

Justintime,

My meter has 1, 1 x 10 and 1K. We used the 1 setting. The goes from the stator to the power pack. (CCC?)

Can I use a standard volt meter and how would I do that? Thanks.

 

[reeldutch]

Re: 1979 Johnson 35hp lost spark

the stator actualy makes ac and is useless for measure ments.
what you need is a volt peak meter.
the voltage peak meter will rectify the ac in to peak volts.
get a digital fluke meter and a cdi peak reading adapter.
http://bpi.ebasicpower.com/mm5/merc...uct_Code=CDI518-16A&Category_Code=OB-OMCTOOLS

peak volts is what you should measure and compare to the servise manual specs.
you will need to do a loaded and unloaded output test.
follow the manual step by step dont skipp.
and it will all fall in place.
ohms test dont say much because even if your ohms readings are in spec, when you put a bigger current threu it it might leak treu a bad insulated wire like a melting coil. arcing

do a stator output test loaded and unloaded

do a trigger output test loaded and unloaded

do a pack output test loaded and unloaded

and do a resistance test on primary and secundary wires on the ignition coils.

if you lost spark on all cylinders disconect the kilswitch wire,
isolate the motor from the ignition switch.
check for spark.
if no spark start test the stator and work your way down to the ignotion coils.
on a 2 cylinder it could be anything.
i dont think its the trigger or pack. check them out any way the packs do go bad.

make shure the ground on the pack is good.

good luck

 

[JUSTINTIME]

Re: 1979 Johnson 35hp lost spark

i posted how to make a dva
u can get one at esitest.com for like $40
i use analog meter, just because the digitals will jump around more

 

[ba_50]

Re: 1979 Johnson 35hp lost spark

It looks like the volt peak meter at esitest is $105 now. Too much for me. I did a seach for the homeade meter using your name but didn't come up with anything. What subject did you use? Thanks.

 

[BoatBuoy]

Re: 1979 Johnson 35hp lost spark

ba_50, here's the link to JUSTINTIME's post:
http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=27;gtid=1199498;gpid=1199498#gpid1199498

 

[JUSTINTIME]

Re: 1979 Johnson 35hp lost spark

thanx boatbuoy

u can just buy a dva for around $40