1979 Johnson 150 "kick"

[emdsapmgr]

Re: 1979 Johnson 150 "kick"

Did you ever try using an inductive timing light to check spark? When running in gear on the lake, have a friend steer, while you remove the cowl. Put the timing light on each wire and note the flashes from the gun. They should be sharp, rhythmic on all 6. Weak firing and misfires should show up in the gun.... If you find one plug or one head that has firing issues: that engine has 6 common coil plugs and two power packs, any of which can be swapped for testing purposes. If the spark is erratic, it could be a bad stator.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

I think its about time to "refresh" this thread to get some feedback. I'm putting another tach on the boat as the old one didn't work, and the new tach well, just doesn't work. It's a Faria 6k tach and the instructions say to put it on -4 for 12 pulse outboard motors as it is now. When I start the boat it'll run up to about 500 RPM's then stop and read zero as the motor is running. All connections were checked, and they are exactly how the old tach was wired up. It lights up fine with the backlight just doesn't read any RPM. To add, my charging system seems to be working correctly as I read 12 volts on my volt guage at all times with motor running. Any input?

 

[jonesg]

Re: 1979 Johnson 150 "kick"

I'm still wondering about that melted battery post you had a while back.!

Put a meter across the batt terminals, read volts. Do it direct with a meter rather than rely on the V guage.
Run the engine and check batt v whilst running high idle, it should now show increased voltage.
If no, suspect rectifier.
If it shows higher v when running then check the grey signal wire from the rectifier to the tach.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

The melted battery post was a bad or corroded connector on the positive wire to the starter. Fixed. Does the signal wire go through the controls or just ran back seperatly?

 

[emdsapmgr]

Re: 1979 Johnson 150 "kick"

If you have a timing light, it will help with your ignition diagnosis. Put the timing light pickup on each plugwire while you are running the engine. The flashes from the gun will tell you a lot about the quality of spark in each wire. The flashes will show misses, weak firing and no fires. Any V6 will run on 4 cyls on the garden hose. It's another thing when you start to load the engine by putting it in the water or shifting it into gear. You need it to be firing on all 6 and you need to confirm you have solid spark. It's easy to do. You have a few options for testing on that engine. You can swap any of the 6 spark plug coils for testing purposes. Also, that engine has two identical power packs which can also be swapped for testing. Once you confirm spark is not an issue, then go back to your fuel issues.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Motor runs great, just need to get the tach working properly so I can dial in the setup and my prop choices. Took a look at the terminal block and I've got two gray wires. One is a little larger than the other and is on the terminal block without anything connected, the other is smaller and isn't connected to any place on the block, both wires however run back to the main "big" red plug. Where does it go, I can't find it in my manual.

 

[jonesg]

Re: 1979 Johnson 150 "kick"

Can you not find a grey wire coming out of the rectifier?
I think one goes to the warning buzzer, the other to the tach.
Do you have a more modern harness on an older engine?

 

[emdsapmgr]

Re: 1979 Johnson 150 "kick"

Referring back to an earlier post, you need to run that engine with the airbox and cover, as it came from the factory. If you run without the plastic airbox cover, the engine will run slightly lean. You have gotten some good advice regarding your tach. Your tach should be set on 6, for your engine. If you have tach problems, you may have issues with the rectifier on the engine. The rectifier does two things, it charges the battery and sends a signal to the tach. You indicate that your voltmeter reads 12.0 volts. Once your run that engine for 15 to 20 minutes, the voltmeter should show charging rates between 15-16.5 volts. If you only read 12 volts, that may be "normal" battery voltage, (normal bat voltage is 12.4-12.6) and the rectifier may not be recharging the batt. That may be why the tach is not working, too. Both of those issues are usually related.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

The tach works properly now guys the gray wire was disconnected from the terminal strip and taped up in the wire harness for some odd reason. I'm still only reading 12 volts all the time though even if the engine has been ran at high idle for more than ten minuets, it just never raises stays above 12 volts. Oh and by the way, the black cover is on and I've always ran it with it on unless I was checking for open butterflies at WOT while it wasn't running. Going fishin' in about an hour I'll come back with some info.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Yeah guys I'm still running 12 volts no matter what RPM I'm running at. Thing is, when I use trim or choke volts drop to about 10 untill I let off of either. Tach works great doesn't jump or anything just doesn't seem to be charging. Also noted trim was super slow when trying to use it after awhile but cranked motor over fast all day.

 

[jonesg]

Re: 1979 Johnson 150 "kick"

Do you read 12v with a meter across the battery terminals or on the dash guage.?
Reading right at the battery would really be the best way.
If your battery isn't going flat, its gotta be charging.

" Also noted trim was super slow when trying to use it after awhile but cranked motor over fast all day. "

Thats not very coherrent.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Made another trip today and got some more results. Noticed the tach works but is very erratic, and before I left I ran it at high idle around 2000 RPMs but I only read 12.5 volts across the battery while running. I also noticed the cranking speed slow a bit as the day went on as I made alot of start and stops. I'm assuming my rectifier is bad but I don't want to assume. OH, also what terminal should the gray sending wire be on on the terminal strip to confirm I have it connected correctly.

 

[jonesg]

Re: 1979 Johnson 150 "kick"

OK you got 12.5 at high idle, but wheres the baseline?
what did the battery read without the engine running.?

Try to do this in an organized manner, step by step.

 

[SparkieBoat]

Re: 1979 Johnson 150 "kick"

CDI electronics has great diagnostic information free...

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Ahhh Jones good point, base was 12.56.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Still got a problem guys. After running and testing for a new prop I believe I have a cylinder down or a timing issue. I only got 4500 at WOT with a 24 pitch Turbo which seems low to me and my crappy idle has returned, came home and did the general tests AGAIN. Found extremely irratic spark on all cylinders, meaning I could find spark at a good constant rate then move to the next cylinder and recieve no spark go back to the previous that I checked and find either weak or no spark. This happend on all cylinders. DVA meter on the way just thought I'd share and get some feedback.

I've ruled fuel out, everything from my tank to my carbs are either new or rebuilt. My idle is odd still which makes me doubt something in the fuel though. #1 reason still what seems like a lean sneeze will caugh a bit then clears up but right after clearing up the rpms may soar another 800 before coming back down caugh then surge making me believe its running lean. Rebuilt all carbs 2 times now. Charging system still isn't up to par I don't believe either. Still only read about 12.5 volts across the battery no matter what (off, running, high idle, etc.) but my tach is still operational. Disconnected reg/rec. still same condition. Warmer weather is around the bend, and I'm starting to lose my patience!

 

[Joshua Nichols]

Re: 1979 Johnson 150 "kick"

I would say replace the CDI unit... They seem to always be the problem with old OMC stuff.. You are saying weird spark and such.. I had a little 65 that drove me crazy... Sometime it would start... Sometimes it wouldn't... Sometimes all cylinders would hit, other times 2 would... Sometimes when you first started out it would run like a dog then catch up and run all day.. Finally it just wouldn't start. Started once more then wouldn't at all.. I broke down and bought one of those aftermarket CDI units..Installed it.. Bam fired up.. Made all the difference.. .. ran perfect.. Drop the throttle and would take off like a scalded ape..

As far as your RPM... You might be over propped

 

[emdsapmgr]

Re: 1979 Johnson 150 "kick"

I'd follow ox's recommendation, and swap the coils and see if the problem moves. The true measure of spark quality is if the spark plug will fire when running under load in the water. (at idle.) Float the boat and secure it to the dock. Remove the cowl and start it- then put it in gear at idle. Check the spark with an inductive timing light. The gun will show the quality of spark on each of the 6 plugwires. It will show intermittents, no fires and weak spark. That engine has two power packs in the ignition system. One for each head. You can swap those two packs and see if any changes occur between heads. If you constantly prime the fuel hose bulb, it will force extra fuel into the carbs. If it runs better while you constantly prime that hose bulb, you may have a weak fuel pump. (if it runs full throttle just fine, likely the pump is ok.) An idle which is too low can be a problem. That engine should idle between 650 and 750 rpm, set when the boat is floating normally in the lake-and is in gear. When you overhauled your carbs, did you remove all the jets and visually inspect them? Also, did you blow some aerosol carb cleaner through the idle passages in each carb, checking the spray outflow from one carb to the outflow from the same passage in the other carb? It's common for old fuel to dry up in the small, dedicated idle passages, causing a lean sneeze. Not many solvents will dissolve dried fuel....

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

I've went through the carbs as well as anyone could and sprayed carb cleaner through all the idle passages. When my DVA meter comes in I'll post on my electrical parts readings. Coils just don't seem likely I've already replaced three because they were leaking potting and the spark issues can and have been related to cylinders with a new coil. My guess is stator for an odd reason because i'm not charging properly still, but who knows can only test will show.

 

[Joshua Nichols]

Re: 1979 Johnson 150 "kick"

So you didn't install carb kits??? How come? They are pretty cheap... So did you pull the screws on the bottom of the fuel bowl and pull out the "orifice plug" and clean it real good? They get funky and cause the engine to run bad.. AKA the jet plug?