Setting the timing

[corapeake]

I have a 1973 or 74 Evinrude or Johnson. It has manual shirt controls and electric start. It's a 115.. My question is, how do I set the timing on this motor. The reason I think its the timing is that the motor runs great until the motor get some heat in it. Then it turn over slow like the timing is off. I need help with this one.

dofunny@myway.com

 

[F_R]

Re: Setting the timing

You need a timing light that will work at high RPMs and a test prop to do it according to the book. There is another way, but I won't go into that now because I doubt that is your problem. Are you saying it runs slow when warmed up or are you saying it cranks slow? If you are saying it runs slow, I'll admit that it COULD be pre-igniting but it wouldn't do it very long before burning up the pistons. So, with that in mind maybe it wouldn't hurt to check the timing. I don't have the specs but if you can find them out, I will share a way to do it. But you still need that timing light.

 

[Joe Reeves]

Re: Setting the timing

Perhaps I'm reading your post incorrectly BUT your description of the problems comes across that the engine cranks with the electric starter properly until the engine gets hot..... then cranks over slowly with the electric starter.

If this is the case, the timing has nothing to do with the problem but is rather a case that the engine is overheating resulting in having the pistons seizing the cylinder walls.

However, the timing on that engine can also be checked as follows.

(Timing At Cranking Speed 4?)
(J. Reeves)

NOTE: If your engine has the "Fast Start" feature", you must disconnect/eliminate that feature in order to use the following method. The "Fast Start" automatically advances the spark electronically when the engine first starts, dropping it to normal when the engine reaches a certain temperture.

The full spark advance can be adjusted without have the engine running at near full throttle as follows.

To set the timing on that engine, have the s/plugs out, and have the throttle at full, set that timer base under the flywheel tight against the rubber stop on the end of the full spark timer advance stop screw (wire it against that stop if necessary).

Rig a spark tester and have the gap set to 7/16". Hook up the timing light to the #1 plug wire. Crank the engine over and set the spark advance to 4? less than what the engine calls for.

I don't know the full spark advance setting your engine calls for, but to pick a figure, say your engine calls for 28?, set the timing at 24?. The reasoning for the 4? difference is that when the engine is actually running, due to the nature of the solid state ignition componets, the engine gains the extra 4?.

If you set the engine to its true setting at cranking speed, when running it will advance beyond its limit by 4? which will set up pre-ignition causing guaranteed piston damage! You don't want that to take place.

No need to be concerned about the idle timing as that will take care of itself. The main concern is the full advance setting.

Be sure to use your own engines spark advance settings, not the one I picked out of the air here in my notes.

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

Let us know what you find, and go into detail a little more if needed if I'm confused somewhat.

 

[corapeake]

Re: Setting the timing

Hey Joe
I think the starter is doing its job. What I am saying is that I can put the boat in the water and start it up and run it about 2 miles and turn it off. Then restart the motor and it will drag or crank over really hard until the battery dies. The motor runs really good. At 5500 RPM it runs about 30 mph. The reason I think its the timing is the person I bought the boat from use to race it.

 

[garywayner]

Re: Setting the timing

Out of curiosity, how could you start the engine with incorrect timing (to adjust it) and not damage the piston? In addition, in case I ever need to do this on my engine, how do you know if an engine has the ?Fast Start Feature? and how do you disconnect it?

 

[redfury]

Re: Setting the timing

Same thing with my buddies boat, ran great until you shut it off and turned over slowly.

YOUR ENGINE IS OVERHEATING. I'd almost guarentee it. You need to replace that water pump impeller and possibly the thermostats as long as you are at it. A cheap part can save you losing the motor.

My buddy thought he knew what he was doing and started messing with the timing, made it run worse, left us stranded on the lake only to troll back and take the boat off the lake in total darkness. He finally broke down and pulled the lower unit off. The impeller vanes were cracking ( old dried out rubber ) and couldn't push water up to the powerhead on its own.

You should have water coming out of the pee hole, and out of the pressure release valves if you are creating enough water pressure from the pump. As soon as he changed the pump, he ran it all day long without a hiccup.

Of course, then he screwed the pooch finally by adding only 6 oz of oil to 6 gallons of gas. Obviously a bad idea as the engine started knocking and died by the end of the day.

Please learn from his mistakes and double check your cooling system before you start to mess with the timing and the carbs, it is so much easier to fix.

And don't trust water coming out of the pee hole if you are running the motor on muffs and the garden hose, especially if you are pressurizing the cooling system from the line pressure from the garden hose.