Johnson will only run with timer base disengaged

[cos_man99]

1983 Johnson 70 horse 3 cylinder (J70ELCTE) was idling fine but bogged badly as throttle was applied. After rebuilding carbs changing sparkplugs I was testing on the lake today. Discovered that if I disconnect the linkage which moves the timer base (to advance the spark) and I held the timer base as far aft as it would go (not allowing it to advance at all as throttle was applied), the engine runs better than it ever has. Jumps out of the hole. Top end is great. Idles smoothly. Starts right up with no choke needed after it is warmed up. My question is: can I run my motor this way without damage? My plan is to use mechanics wire to lock the timer base in position. Or do I need a new timer base or other part? Thanks so much for any insight you may offer.

 

[jakedaawg]

Probably need to either link and synch properly or find the bad wiring from timer base to power pack. I suppose power pack also could be at fault but I would think timer base wiring.
This has a four pin am phenol connector tucked in behind the timing arm on starboard side of block. Disconnect and ohm as per manual and you will probably find anew open especially if you manually move timer base while doing the resistance checks.

 

[cos_man99]

Jakedaawg, thanks so much for the reply. I was going to try the ohm test to see if I could find a fault in the timer base but I'm thinking it runs great this way. I only paid a thousand bucks for boat, motor, and trailer. Will it hurt anything if I run it with the timer base disengaged?

 

[racerone]

???-----I believe you need to check the flywheel key.------Do NOT run the motor the way it is !!

 

[jakedaawg]

Excellent point as usual racerone

 

[cos_man99]

The more I think about it the more I'm thinking the timing is advanced already despite where the timing base is. It idles a little high (not bad). I believe the timing is designed to be retarded to make the idle lower (I may be wrong about that). So my guess is that the timing is advanced and when the timer base tries to advance it even more it is advancing too far.

 

[racerone]

??----So check the flywheel key !

 

[jakedaawg]

He is absolutely correct. It has to be flywheel key. All three magnets would not slip the same amount of degrees. Has to be the key.

 

[cos_man99]

I do not have an impact wrench. Is there a way to get the flywheel off without one?

 

[jakedaawg]

You do not use an impact or a Hamer. Use the proper six point socket, and a spanner wrench to hold the flywheel. Then use a 3 bolt puller to pull flywheel. Again, NO Hamer or impact.

 

[cos_man99]

Thanks so much, everybody. I'll post here what I find when I get the flywheel off. I am so thankful that there are nice folks like you all who could help me figure this out.

 

[sutor623]

I have always used an impact to pull the flywheel nut off, just not to put it back on. Why would this be an issue? I can see it being an issue re-installing the flywheel nut with the impact gun!!!

 

[interalian]

I have always used an impact to pull the flywheel nut off, just not to put it back on. Why would this be an issue? I can see it being an issue re-installing the flywheel nut with the impact gun!!!

A couple of things spring to mind.

First, you're jolting some precision parts such as bearings and highly polished journals on the crank.

Second, when I worked at a marina many years ago, we used to see a lot of problems with tearing the threads off the crank where the nut mounts. Seemed to happen on the 3 cylinder motors. Whenever it happened the motor had to come apart and the crank sent off to a machine shop to have threads welded and cut. I think the mechanics used impact guns...

 

[sutor623]

A couple of things spring to mind.

First, you're jolting some precision parts such as bearings and highly polished journals on the crank.

Second, when I worked at a marina many years ago, we used to see a lot of problems with tearing the threads off the crank where the nut mounts. Seemed to happen on the 3 cylinder motors. Whenever it happened the motor had to come apart and the crank sent off to a machine shop to have threads welded and cut. I think the mechanics used impact guns...

Yikes. Luckily I have never had these issues............. They use brass nuts so I would think that would be the first thing to fail, but sure wouldnt want to find out the hard way!!!!

 

[racerone]

Never seen a brass flywheel nut on an OMC motor !

 

[interalian]

Never seen a brass flywheel nut on an OMC motor !

Yellow chrome likely.

 

[sutor623]

Well it is a softer metal, whatever it is.

 

[racerone]

They use a steel nut !!----Try a magnet on one next time.

 

[sutor623]

I guess the color threw me off. Must be hardened steel?

 

[flyingscott]

A couple of things spring to mind.

First, you're jolting some precision parts such as bearings and highly polished journals on the crank.

Second, when I worked at a marina many years ago, we used to see a lot of problems with tearing the threads off the crank where the nut mounts. Seemed to happen on the 3 cylinder motors. Whenever it happened the motor had to come apart and the crank sent off to a machine shop to have threads welded and cut. I think the mechanics used impact guns...

You really don't jolt anything with an impact just put your hand on the flywheel acts as a shock absorber. The easiest and safest way to get the nut off is with an impact gun.The threads stripping just sounds like somebody did something wrong more human error than impact gun. The nut is zinc plated steel that's why it's yellow for corrosion resistance. Never put a nut on with an impact that is where the problems start.