Setting points/timing on 15hp johnson

[poida]

Hi all
Setting the points on my 15hp m/n 15404G. I can not find my feeler gauges to set the initial .02 setting but don't think i need to as according to the machinists site as this is only an initial setting and i need the points to open as my timing marks pass another mark on the armiture/magneto plate mark.

"With new points, set the flywheel mark to fire in the middle of the large fixed magneto plate mark"

I don't seem to have this mark, i have attached pictures front and back for both cylinders of when the points open, is there a mark i am missing on my outboard to time the opening of the points too?

PS What year is this outboard?

 

[F_R]

Re: Setting points/timing on 15hp johnson

I make timing fixtures for that motor. Here is one on a stripped armature plate, pointing to the timing mark.

Your motor is a 1974, with Lo-Tension Magneto

 

[series60]

Re: Setting points/timing on 15hp johnson

PS What year is this outboard?

Google 15404G. It's a 1974

 

[OptsyEagle]

Re: Setting points/timing on 15hp johnson

You should have marks like the 1 and 2 of the picture below. I would invest in a new feeler guage if I had taken the time to remove the flywheel already. You will either need those marks or a feeler guage to set those points, and I prefer to use both. I first set the points to 0.020". I will then attach a multimeter to the point lead and the other to ground and set it to measure continuity. I will then turn the cam until the continuity just stops (point just opens). Then, I very carefully set the flywheel in place and visually see if the timing marks are where they should be. Once I see that they are, I make note of the measured point setting and use that forever more. So far on two motors of the same vintage as yours, it has always been 0.020". No more, no less. If they are new points I will set them closer to 0.022" to allow for some initial wear.

 

[kbait]

Re: Setting points/timing on 15hp johnson

On that particuar motor (9.9/15hp '74-'76), you can remove one of the armature plate mounting bolts, feed a wire through and connect to one pointset (disconnect other wires), connect your feed wire to one lead on your multimeter, the other lead to powerhead ground, replace flywheel (don't torque down) and spin slowly clockwise to see when you lose continuity.. that is where that pointset opens and the plug would normally fire. At initial setting of .020", you should be really close to the mark that optsy attached above. To adjust, open points slightly to advance, close to retard. Kind of tedious, but it works. Also, check for any lateral play in armature plate. Any slop there will directly translate to the point gap, and throw it all out of whack. I use FR's tool for 5.5-18hp's, and it is AWESOME and easy to use, if you want to go that route.. just be sure to order the correct tool for your particular motor type.
Good luck!

 

[poida]

Re: Setting points/timing on 15hp johnson

I do not have the marks on the armiture. The points are old so can i just set them to .02 and presume that all will be ok?
The motor will bog down and not idle low so i was hoping to set the timing and see what happened.
I have 100psi on both cylinders and the carb kitted out.
Wonder where my marks have gone???
Might have to visit the local outboard collector and see if he has an armiture to suit.

 

[poida]

Re: Setting points/timing on 15hp johnson

I do have some lateral slop (i have retensioned the brown ring under the armiture plate) but this is down to the 90dg bevel gears. When under full throttle or in the start engine position there is no movement but at low idle there is lateral movement (due to gear slop) that i need to fix up. I was intending to rip into it after setting the timing. I was going to attempt to shim it as per the ramblings, so i guess that this could not be helping my low idle problems.

 

[OptsyEagle]

Re: Setting points/timing on 15hp johnson

Setting the points to 0.020" is fine. You don't need the timing marks, but it is bizarre that you don't have them. You also want to make sure your carb is sync'd with the timing advance. For this you want to ensure that the carbs roller hits the throttle cam at the arrow mark on the throttle cam. This is the point where the carb butterfly just starts to open. Do that and set your points to 0.020", your timing is now set.

The other test I would do is verify that both cylinders are strong and firing. First do an external spark test to ensure that both are firing and the ignition is strong enough to jump a 3/8" gap. Then I would fire the motor up and let it warm up and at a fast idle, using insulated plyers, pull off one spark plug boot at a time. The motor should be able to run fine on either cylinder so if the motor dies when you pull a boot, you know that the other cylinder was never firing or was very weak.

Lastly, and this is probably not your problem, but I would also suggest, for that model, to use NGK B7HS spark plugs, gapped at 0.030" over the recommended Champion brand. You can search this site for why but in that model your Champions just won't work as well.

 

[poida]

Re: Setting points/timing on 15hp johnson

Right, thanks for the info.
The timing on the carb is good, i will rip into the shed and find my feeler gauges and set to .02.
I'll check the spark too, thanks.

 

[poida]

Re: Setting points/timing on 15hp johnson


Hi all.
I set the points to .020 and tried to start her. When started (and it did not for a fair few pulls) it idled really low, lower than it was before i set the points to .020. If you pop her into forward and crack the throttle a bit more then she starts ok.
There is no way i can increase the idle speed as the adjuster is already maxed out, pic attached. I could grind a piece off the armiture or adjustable arm but still don't know if the timing is correct, and since it got worse since setting the points (i also eliminated the slop in the gears) i wonder if this armiture is worth persevering with. I found a 2nd 1974 outboard but found that it was converted to a cd ignition but has no coil packs etc so i am stuffed again. I have rechecked the points and all seems to be ok.
The spark jumps a 3/8 gap.
Link and sync good.
100psi on both cylinders
It now seems like trying to start a car that idle's at 800rpm at 700rpm, it needs rev's to start cold and i can't increase them with the throttle grip and in neutral.
Do these old points and condenser motor's run well, or should i look at converting it to a cd flash ignition?

 

[OptsyEagle]

Re: Setting points/timing on 15hp johnson

Whenever I hear of someone with hard starting issues I usually want to look closely at the synchronization of the carb to the throttle cam. You have indicated that yours looks good, but in looking at your pictures, I wonder if your carb's roller is standard or something jerry rigged to work (and perhaps not working so well). Below is a picture of my 1975 9.9Hp with the air silencer removed. This is the same basic motor as yours. You will notice that my carb's roller is considerably different then yours. Mine seems to be a much smaller diameter. Perhaps some others, who might have the 1974 model, can chime in here and tell us if yours is standard or not.

In any event, you could probably adjust yours to work or at least help you start it easier. It may throw off some other parameters of your timing advance but at least you can get her started without throwing out your arm. Obviously your problem is that your motor is not getting enough gas for starting. If you adjust your throttle cam so that the roller hits the cam a little BEFORE the mark, then your carb will be putting out more gas when you hit the neutral stop and perhaps start a little easier. Unfortunately your spark timing will be happening a little sooner then your want. This won't be a problem for starting (as long as you don't set it too far before the mark) but might reduce your performance at WOT.

Maybe some others can chime in on my idea here. Obviously it is not optimum but might help. Maybe you are having some other problem that I am missing.

 

[poida]

Re: Setting points/timing on 15hp johnson

Optsy
The flywheel nut has been previously removed by a cold chisel, the fuel pump rebuilt back to front and the armiture lacks timing marks, i think the previous owner had no idea. This motor having 100psi should run like a top though, or am i missing something?

 

[poida]

Re: Setting points/timing on 15hp johnson

If you want a pic of the roller or anything let me know, this motor has certainly had a 2nd power head and possibly has a mixed up armiture.

 

[kbait]

Re: Setting points/timing on 15hp johnson

If the cam follower (roller) doesn't open the throttle plate slightly when you're in neutral and advanced as far as the tiller will go (until it hits the safety stop), you can put a few wraps of electrical tape on the roller itself to let the throttle plate open slightly at starting (neutral) throttle position. I seem to remember that you can't really adjust the cam to compensate. I've done this several times w/great results. You don't need the throttle plate to open much, but it must open a little for cold starting.

Good luck!

 

[OptsyEagle]

Re: Setting points/timing on 15hp johnson

Sure, I understand. Do you understand what I mean by the roller possibly causing you the problem you describe. All you are doing when you put it in gear is allowing your roller to move a little further up the throttle cam. This pushes the roller back a little further opening up the throttle butterfly a little more, providing a little more gas for starting.

A pic won't help me because I do not know what a 1974 carb roller should look like, but since the 1974 to 1976 are basically the same engine, I would have assumed it would look like the one I posted. It appears to me that it is different then yours. Now if all the amateur mechanic did was put that roller on your carb, then it should in itself, push the throttle back a little more due to its larger diameter, but perhaps he adjusted the throttle cam as well to try to account for it. These are things I do not know, but I do know that a little reduced throttle can make your motor a real bear to start.

I would also make sure your choke is operating properly, as well.

 

[oldman570]

Re: Setting points/timing on 15hp johnson

Here is a link that should explain the trouble you are having and the best ways to set the points on your motor.
OMC outboard related articles
The jig that FR makes will save alot of trouble of taking the flywheel off an on all the time as you can set both of the pointrs vary easy using it. The ohm meter method mentioned by Optsy Eagle is in the link, and is better to use for setting of used points. JMO
Oldman570

 

[poida]

Re: Setting points/timing on 15hp johnson

The cam is adjustable on this motor. I have set it so it just starts to open when the mark hits the roller, and as you advance past the mark the the throttle opens a little. So if the roller is wrong then i have already compensated for it. I will adjust the cam (have the flywheel off atm) and post the results. Optsy, what you are saying with the cam roller makes sense.

 

[the machinist]

Re: Setting points/timing on 15hp johnson

The photo you have posted of what you call the idle speed adjuster is not that, it does dual duty as a shifting stop positioner and a anti-rev limiter when in neutral or reverse.

The carb cam roller is usually a milky color and .465" dia. for those older motors. I suspect your carb may be off a newer motor, which may not really be a problem if it is sync'd to the timing cam plate. Does it have a metal or black plastic bottom fuel bowl? Post a photo of it for a better ID.

 

[poida]

Re: Setting points/timing on 15hp johnson

The fuel bowl is metal.
Well, i gave the cam a good tweek, put the flywheel back on and she started 2nd pull. It now start easily every pull, this outboard has never run this well before. I wouldn't mind a few more rev's on max throttle in neutral but can't complain with how she starts so i think i will leave it as it is.
The only thing left to do is to give her a full run across the inlet and see if the bogging down issues are fixed.
Thanks again for advice.