Timing a 1974 15 hp Johnson

[Thumper2442]

I bought a 15 hp Johnson to upgrade my jon boat from a 9.8 Merc. The first time out it overheated. I fixed that. Then it wouldn't run right. I checked compression and one cylinder was only 60psi. I replaced the rings and have good compression on both cylinders now. Now it lacks power. I paid for a Seloc online manual so I could adjust the timing and all it told me was small engines use the point gap to adjust the timing. I already know that's wrong. I've had the flywheel off more than once, set the point gap, and still can't figure out how to set the timing. I put a timing light on it and the lines on the flywheel don't sit anywhere near something that could be mistaken for a timing mark. There is a raised part with lines and a hole in it on the back under the flywheel. Is that what the timing is set by? There's no sign of degree marks on it. I'm trying to get this thing going for the week after Labor Day. Can anyone help? Thanks.

 

[Joe Reeves]

Re: Timing a 1974 15 hp Johnson

The timing on that engine is simply set by the flywheel key matching the flywheel to the crankshaft. If that flywheel key isn't sheared, the engine is in time.

Perhaps you're using the wrong procedure in setting the points. See the following.

(Point Setting Of Magneto Models)
(J. Reeves)

Set the points as follows. Have the flywheel key aligned with the fiber rubber portion of the ignition points. Adjust the gap so that a .020 gauge will pass thru but a .022 will not. Should there be any question of the points being dirty (touching the contact with your finger would cause them to be dirty), clean them with a small brush and acetone or lacquer thinner.

NOTE: Should the operating cam have a small portion on it with the word "SET" imprinted, align this portion with the fiber rubbing portion instead of the flywheel key.

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store

 

[Thumper2442]

Re: Timing a 1974 15 hp Johnson

Thanks for the help. If it is in time then I wonder what else could cause the lack of power. I've researched it on prior posts and I can't figure what it might be. The carb appears to be in sync, I believe the prop is correct, the float was shot so I replaced it, I rebuilt the fuel pump and squeezing the primer bulb doesn't improve the power any, I took a piece or gunk out of the high jet (it actually ran better with it in). I wonder if the prior owner changed the high jet? Anyway, any suggestions would be appreciated. I already have way to much invested in this motor and haven't had one good outing with it.