setting the timing correctly on a 1989 johnson gt 150 tj150sclem

[kknopp01]

HI all,

i have a 1989 johnson gt 150 tj150sclem that i have just rebuilt, replaced a sheared key, and the last issue id like to fix and or check is the timing.

how can i set the timing on this motor & what should it be set too?

Thanks!

[Joe Reeves]

i have a 1989 johnson gt 150 tj150sclem that i have just rebuilt, replaced a sheared key, and the last issue id like to fix and or check is the timing. how can i set the timing on this motor & what should it be set too? Thanks!

Check your model number of that engine. The one you listed does not exist.

I don't have the timing specifications of the engines. If no one answers you here, ask for the timing specifications on the Evinrude/Johnson forum at MarineEngine.com .

When you have that info, time it 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 temperature.

The full spark advance can be adjusted at cranking speed,"without" have the engine running 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 up a spark tester on the #1 cylinder plug wire. 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.

It's a good idea to ground the other plug wires to avoid sparks that could ignite fuel that may shoot out of the plug holes. I've personally never grounded them out and have never encountered a problem but it could happen.

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 components, 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.

A fellow member from one of the various marine forums suggested having water supplied to the water pump (flushette or barrel) simply to provide lubrication to impeller. A worthwhile suggestion I thought, and entered here.

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

[kknopp01]

Thank you for the info! i will go find the called for timing degrees and as for model number i may have swapped one, willl get correct one after work!

could u elaborate about setting the actual value. lets say it calls for 28, set to 24 done by attaching the light to cylinder one, but where does the actual adjustment happen? is it done by adjusting the dial located on the air box where the cable enters the cowling ?

Thanks again

[kknopp01]

model number TJ150SLCEM

ive heard the model calls for 28 degress but i am not sure as i read this in passing while trying to figur eout rebuilding my carbs awhile ago

[Joe Reeves]

could u elaborate about setting the actual value. lets say it calls for 28, set to 24 done by attaching the light to cylinder one, but where does the actual adjustment happen? is it done by adjusting the dial located on the air box where the cable enters the cowling ?

Using my method, the timing must be set 4 degrees lower than what it actually calls for..... yes, if 28, then set to 24.

The actual adjustment..... look under the flywheel and move the timer base to advance the spark. See the rubber cup that is on screw head which is locked in place by a lock nut? That is the full spark advance stop screw which sets the timing.

The timer base must be right up against that rubber cup when setting the timing.