1990 Force 50 timing way off

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
You must go step by step or you are just pissing into the wind.
Flywheel FA658097
Trigger 888798
Stator 300-888793
COIL ASSY-IGN 300-888791

It is possible that although the triggers look the same you have one that is incorrect. If TDC occurs at the TDC mark and you can set the 30* WOT (plugs removed and wires shorted to ground). then the timing must be correct. If not you have a trigger problem,
It is alos possible that the trigger magnets have shifted on the hub, but unlikely.

. Disconnect the ball link to the carb cam at the timing tower. Disconnecting at the cam risks bending the cam. Move the cam away from the carb roller.
2. Loosen the screw(s) on the aluminum tie bar and let all carbs close completely, then tighten again.
3. Set the cam so that the scribed line is pointing directly at the black roller on the carb lever. If the cam has two closely spaced lines, set the black roller directly between them.
4. The black roller is held with an offset screw and nut. Loosen the nut and turn the screw until the black roller JUST touches the cam. Tighten the nut and re-attach the ball link maintaining the scribed line at the roller.
5. Adjust the ball link so that at full throttle the bottom carb butterfly opens substantially horizontally. Adjust the aluminum tie bar so all carb butterflies open equally at full throttle. They need not be perfect but should be rather close to horizontal for best performance.
6. Adjust timing to 30 degrees before top dead center at full throttle.
7. Adjust idle speed to 700-750 RPM in the water in forward gear. Do this with the screw on the bottom of the timing tower. Loosen the locknut and adjust. Screwing in increases idle speed. Do this in small increments and let the engine rev and adjust itself before the next adjustment. A little goes a long way here. When correct, tighten the nut. Note that the scribed line on the roller will now be (usually) below the black roller a bit.
8. NOW we adjust the mixture on the carbs. Set all low speed needles to about 1 1/4 turns out from lightly seated. Do not force as this will damage either the needles or the seats.
8A. With the engine idling in neutral, turn each the needles in equally about 1/8 turn at a time. Give the engine a couple of seconds between each adjustment to stabilize. Adjust until the engine either "sags" or stalls. Note this setting.
8B. Now go the opposite direction. Adjust until the engine runs rough, burbles, or stalls. Note this setting.
8C. Set all needles to the average between the two settings: That is, for example, if it stalled at 3/4 turn out and burbled at 1 1/4 out then set all needles to 1 turn out.
8D. Readjust idle speed to 700-750 RPM.
9. Take the boat out on the water and do a "hole shot"--Full throttle acceleration from a stop. If the engine "sags" then recovers and picks-up it is too lean. Open the needles about 1/16 turn at a time until the engine accelerates with no hesitation.
If the engine sputters or coughs or burbles, then clears itself and accelerates, it is too rich. Close the needles about 1/16 turn at a time until the engine accelerates smoothly.


10. I can NOT stress this enough! NEVER set the low speed needles less that 3/4 turns out no matter how poor the idle or acceleration. To do so will run the engine too lean and detonation and melted pistons at or near full throttle operation will result.

This should be a sticky; it would save us a lot of repeating lol
 

Redbarron%%

Chief Petty Officer
Joined
Dec 7, 2017
Messages
479
In all honesty it was copied off of this forum and I would have to go back and find who wrote it and give them credit fo the knowledge.
 

MrMarty51

Seaman
Joined
Aug 4, 2020
Messages
53
This is a very interesting thread.
being a heavy equipment mechanic for over 30 years I did not get much time on the small stuff like this.
I have tuned on quite a few motorcycles and Wisconsin engines and a lot of those state to not use the battery that is attached to the engine being tuned as the charging system can create a false signal and flash the timing light.
apparently that situation is not a problem with these Force engines. That is what I was going to suggest could possibly the problem why the timing was so far off. I had never heard of a CDI unit firing on just half of its circuit.
 

mysteryboy28

Cadet
Joined
Aug 2, 2020
Messages
20
This is a very interesting thread.
being a heavy equipment mechanic for over 30 years I did not get much time on the small stuff like this.
I have tuned on quite a few motorcycles and Wisconsin engines and a lot of those state to not use the battery that is attached to the engine being tuned as the charging system can create a false signal and flash the timing light.
apparently that situation is not a problem with these Force engines. That is what I was going to suggest could possibly the problem why the timing was so far off. I had never heard of a CDI unit firing on just half of its circuit.

I almost bought the self-powered timing light. But So far I'm having better results testing with the motor running. Because it wasn't a timing issue - it was a faulty CD unit. I'm going to take it out on the lake on Sunday, with a passenger, so I can get a REAL timing reading at WOT. Sadly I just fried my new impeller trying to use my new muffs (as opposed to a tub of water). New one ordered...
 

MrMarty51

Seaman
Joined
Aug 4, 2020
Messages
53
I’m watching this thread and will be waiting to see the results posted. Be sure to replace the impeller so more bad things do not happen.
 

MrMarty51

Seaman
Joined
Aug 4, 2020
Messages
53
The 50 needs a special muff to insure the waters being picked up.

😳 that thing is huge. 👍😹

I did find out, solid core spark plug wires will give a very inconsistent flash on My Mac Tools inductive timing light. I made a carbon core wire and flash was very good. Old wore out 70 horse is spot on for timing.
 
Top