1988 120 Johnson V4 flywheel que

[mikey45]

I recently tried to set the timing on this motor. I found that I had to advance the timing screw as far as it would go to get it "near" the target setting of I believe 16 degrees at WOT. I cannot get the timing mark to go any closer than 14 degrees. Also, my tach is now giving me readings all over the board. I think there is something under the flywheel that needs to be replaced. I am not sure what. Is it a stator? Where do I get the socket at to get the nut off the flywheel? All my sockets are too bulky. Will changing the stator fix my tach problems and timing problems? Please help!!

 

[WillyBWright]

Re: 1988 120 Johnson V4 flywheel que

The stator only makes electricity, it has nothing to do with timing. It does provide the signal for the tach, but it's rarely the cause of a tach problem. It's usually the tach, regulator/rectifier, or loose or corroded battery connections.

 

[ezeke]

Re: 1988 120 Johnson V4 flywheel que

Did you make allowances for QuikStart when you set the timing?

The signal for your tach is from the rectifier. Try moving the gray signal wire to the gray and yellow wire off the alternater and see if the tach works properly. If it does, you probably need to replace the rectifier ASAP.

 

[mikey45]

Re: 1988 120 Johnson V4 flywheel que

I dont think I have an alternator on this motor. I was under the impression the flywheel made the juice and the power pack regulated it. Where is the regulator/rectifyer? Under the flywheel? Also, could you tell me about quickstart? Never heard of it.

 

[ezeke]

Re: 1988 120 Johnson V4 flywheel que

The electronics centered under the flywheel generate alternating current for both the ignition and for charging. The rectifier converts AC to DC and the regulator controls the voltage for charging.

The regulator/rectifier is under the powerpack, mounted so that it is cooled by incoming water.

The big bore loopers like yours came with powerpacks that incorporated QuikStart and S.L.O.W. In terms of timing, QuikStart is the importatnt one, because whenever the engine is started, QuikStart automatically advances the timing to make starting easier. If you attempt to change the timing without following the procedure outlined in your model's service manual, you will likely not improve matters.

The reason that it is important to check your rectifier ASAP is that it is similar in every problem area to the one in this thread:

http://forums.iboats.com/showthread.php?t=207444

 

[mikey45]

Re: 1988 120 Johnson V4 flywheel que

Oh brother. I appreciate the info. Im gonna check it out. Thanks also for the vent idea. I may do that as well. Can you tell me the trick to getting the nut off the flywheel? I believe its 1 1/2 inch nut but cant get a socket on it. Too bulky or maybe a special tool?

 

[ezeke]

Re: 1988 120 Johnson V4 flywheel que

The nut is actually 1-7/16, I believe, and you need a thinwall for the 120,125 and 140 flywheel. You might just grind one down if you can't find one.

 

[Dhadley]

Re: 1988 120 Johnson V4 flywheel que

How are you checking the timing? Be careful running the motor with the stop screw more than about 1/2 way out.

 

[mikey45]

Re: 1988 120 Johnson V4 flywheel que

Thanks on the socket. It looks like something I may need to do. Grind one down.
How am I checking the timing? I basically and correct me if I am wrong according to the manual, placing the gun wire on the highest cylinder spark plug and running the motor with the ear muffs at 5500 rpm in gear. Not saying the manual said to run it with the muffs but I thought it would be genuine. Is there a more accurate way to check the timing by myself?

 

[Dhadley]

Re: 1988 120 Johnson V4 flywheel que

You're not getting a true reading. If the motor is not in the water there's no pressure on the prop so putting it in gear doesn't do anything. Except possibly hurt someone. If it slings a blade out of the water you'd be shocked to know how far a blade will go. Trust me.

You also stand a pretty good chance of the motor running away. If it runs away there's no real way to shut it off except to flood it somehow. If you can't shut it down you also stand the chance of scattering it. You need some type of load on the prop. It needs to be in the water with either a test wheel or a real prop.

Once you get the other issues resolved, put the timing stop screw about half way and check the timing under a load. Or by Joe Reeves method. But don't run the motor with that screw all the way forward. You'll be looking up piston part numbers.

 

[mikey45]

Re: 1988 120 Johnson V4 flywheel que

I was messing around looking for corroded wires on the starter side and found a red line with a small glass fuse between them. After finding it corroded, I replaced it with a new one and cleaned it up. I also took off the cover for the power pack and couldnt find any loose or corroded wires. I did see the rectifyer underneath. I put it all back together and now it wont start. checked the plugs and they are all dead. I guess whatever was getting ready to go went. Whats your advice, powerpack and rectifyer? Got your messg on the timing thing. Will do it in the water from now on.

 

[ezeke]

Re: 1988 120 Johnson V4 flywheel que

If the fuse is on the smaller red wire running from the large connection on the starter solenoid, it is the fuse to the harness for the only positive power on the remote control.

The fuse is easy to blow and if it is blown will not allow you to engage the starter solenoid.

If the starter is working, disconnect the black and yellow kill wire at the powerpack and see if the engine will start. Be prepared to stop it, since the key stop won't work with the wire disconnected.

 

[mikey45]

Re: 1988 120 Johnson V4 flywheel que

I just went ahead and took off the power pack and the rectifyer. Power pack looked okay but I guess you cant really tell. Rectifyer was slightly corroded but looked good to me. Is there a way to test them?

 

[ezeke]

Re: 1988 120 Johnson V4 flywheel que

Edit - wrong test,

 

[mikey45]

Re: 1988 120 Johnson V4 flywheel que

Will do. Any way to test the power pack?

 

[mikey45]

Re: 1988 120 Johnson V4 flywheel que

Okay. Is there another test I can try?

 

[mikey45]

Re: 1988 120 Johnson V4 flywheel que

I ordered the new rectifier and power pack. Thanks for the help guys. I guess if it still doesnt start Im lookin at the stator. I will respond soon with the results.