Timing waaaaay off????

[Daremo]

Something isnt making sense here....

2 stroke 90 hp motor, timing mark is at the front of the motor, yet when its running, the white marks are a full 145 degrees off.... I am not as familiar with 2 stroke engines as much as I am with 4 stroke. I am thinking this is something very basic.

Using a standard timing light with inductive pickup on cyl #1.

The engine runs when I crank it, and it didnt seem to move the timing marks when i adjusted the trigger timing adjustment.

could I have installed my replacement stator wrong? ie not in the right bolt holes?

 

[Barnacle_Bill]

Re: Timing waaaaay off????

Timing is not done with the motor running. It is done thru a procedure called link & sync. Detailed instructions are in your manual.

 

[Daremo]

Re: Timing waaaaay off????

Timing is not done with the motor running. It is done thru a procedure called link & sync. Detailed instructions are in your manual.

uhhh ignition timing is most certainly adjusted with the engine running. Hence timing light and timing marks. Both which ARE specified in my manual, which i am following...

 

[Chris1956]

Re: Timing waaaaay off????

You might post year of motor.

Do you have the red outer flywheel that unbolts from the inner flywheel via 8 5.16" fine thread bolts? If so, the outer flywheel may have been installed incorrectly. Set the top piston to TDC using a screwdriver thru the plug hole. The timing pointer should read about TDC. if not, either the flywheel is installed incorrectly, the timing pointer is out of adjustment or both.

 

[Daremo]

Re: Timing waaaaay off????

You might post year of motor.

Do you have the red outer flywheel that unbolts from the inner flywheel via 8 5.16" fine thread bolts? If so, the outer flywheel may have been installed incorrectly. Set the top piston to TDC using a screwdriver thru the plug hole. The timing pointer should read about TDC. if not, either the flywheel is installed incorrectly, the timing pointer is out of adjustment or both.

I intentionally didnt post the motor because its been rather difficult to get people to answer questions on this motor, and this particular problem is more likely to be something that you might run across with more than one particular model.

Its a 95 Sport Jet 90 which is also essentially the same as a Force block of earlier years. It does have a red stator and there are either 6 or 8 hex key cap screws holding it in place. The flywheel can not be installed incorrectly as its got a key, the pointer I am trying to line up is the seam between both halves of the block, so thats not adjustable.

According to the manual, it should be timed to approx 8-10 deg BTDC. Its not even close to that. With the engine running, and the with the timing mark on the block at 6 O'Clock in relation to the flywheel, my timing marks on the flywheel with the timing light are at approx 1-2 O'Clock. Thats my issue.

Course, now that I am writing this out, I have realized I have 3 possible reasons for this that I can think of.

1. I'm not actually at idle. The boat doesnt have a tach, so I dont know if I am truely at idle. I do have a tach/dwell that I can hook up, so I will have to do that.

2. I didnt install the stator correctly, ie I have to rotate it one more bolt hole. Though in my defense, I did install it according to the diagram that came with it, and also in the same location as the previous one.

3. The magnets had broken loose on the flywheel. I did re-epoxy them back on in approximately the same place, so I dont believe thats the issue, but I suppose it could be, though if they arent exactly lined up, they are VERY close.

 

[hkeiner]

Re: Timing waaaaay off????

uhhh ignition timing is most certainly adjusted with the engine running. Hence timing light and timing marks. Both which ARE specified in my manual, which i am following...

On my motor, the "maximum timing adjustment" is done with a timing light and timing marks with the motor cranking but with the spark plugs removed. The motor is not "running" per se, it is only turning over with the starter. The "low speed timing adjustment" is done with the motor running but a tachomometer is used set the idle timing to attain the correct idle speed. No timing light is used at all. A timing light can be used with the motor running at WOT to confirm that the " max timing" is set OK, but not to adjust the timing while the motor is running at WOT. The idle timing spec is a range and the actual idle timing can be anywhere withing this range and still be OK. It is the motors's idle RPM speed that matters when setting the idle timing.

 

[hkeiner]

Re: Timing waaaaay off????

The flywheel can not be installed incorrectly as its got a key, the pointer I am trying to line up is the seam between both halves of the block, so thats not adjustable.

Aligning the flywheel with a seam on the block does not sound right to me. I would expect that there would be an adjustable timing pointer that would be aligned with the appropriate mark on the flywheel using a dial indicator. This step would be described in the link and sync section of the shop manual along with a picture of what the timing pointer looks like and where it is located on the motor. As an example, below is a pic of a timing pointer from a Merc shop manual for a 1987-1993 90hp with serial numbers 0A996142 thru 0D283221 (USA).

Perhaps I just don't know enough about your particular motor and my comments do not apply. If so, sorry about that...

 

[Barnacle_Bill]

Re: Timing waaaaay off????

The only setting done with the motor running is the final idle setting. The rest is done using just the starter.

 

[CraigC]

Re: Timing waaaaay off????

If that really is the case and you're that far off, the stator is in the wrong location. I'd double check it.

 

[hkeiner]

Re: Timing waaaaay off????

Or... you are checking the timing against the wrong "timing pointer" position. Unless you first confirm the timing pointer position, using the dial indicator procedure, you may be getting false readings with the timing light. I would think that if the timing is really that waaaaay off, the motor would not be able to run at all. Just my thoughts....