I have a 2002 60hp Mariner 2 stroke, I recently replaced the trigger. After installing a second hand merc trigger I followed the manual and set the idle timing to +-1 TDC at cranking speed on cylinder number 1 (top cylinder), and WOT timing to 22B.T.D.C. The engine started and ran rough and then stalled (was the first time its ran in a few years) it was late and I didn't want to make anymore noise so I followed the manual's procedure to do a carb link and sync, and changed the fuel filter and called it a night.
The next day I decided to double check the timing at cranking speed before I started the engine incase the link and sync had altered it at all. With a timing light attached to spark lead number 1 (top) the timing was completly wrong, like very wrong. My first thought was the maybe when it ran and then stalled it had sheared the keyway on the flywheel so I checked by putting cylinder one at TDC and confirming the timing pointer aligned with TDC on the flywheel. It did so that rules that out. Out of curiosity I put the timing light on the other spark leads. It is perfectly timed for cylinder number 3 now so -+1TDC at idle/22degrees B.T.D.C at full throttle stop.
I started the engine and it runs completly fine, actually much better than the night before which I think is to do with fine tuning the link and sync. On this model engine there is no way to possibly have the spark leads connected in the incorrect order because they do not reach nor do the cables at the back of the CDM modules. I also haven't touched any of the wiring to the trigger or stator.
How could it possibly have changed its firing sequence from 1,2,3 to 3,2,1? In the manual it says the firing sequence is 1,2,3 and the night prior it started showing the timing correct according to the top cylinder? Anyway the engine seems to run fine although I have only ran it on the muffs so far and not WOT on the water yet. I am just very confused why the timing is showing as incorrect with the timing light on spark lead one, but showing as corerct on spark lead 3. Is it okay to continue running it like this?
The next day I decided to double check the timing at cranking speed before I started the engine incase the link and sync had altered it at all. With a timing light attached to spark lead number 1 (top) the timing was completly wrong, like very wrong. My first thought was the maybe when it ran and then stalled it had sheared the keyway on the flywheel so I checked by putting cylinder one at TDC and confirming the timing pointer aligned with TDC on the flywheel. It did so that rules that out. Out of curiosity I put the timing light on the other spark leads. It is perfectly timed for cylinder number 3 now so -+1TDC at idle/22degrees B.T.D.C at full throttle stop.
I started the engine and it runs completly fine, actually much better than the night before which I think is to do with fine tuning the link and sync. On this model engine there is no way to possibly have the spark leads connected in the incorrect order because they do not reach nor do the cables at the back of the CDM modules. I also haven't touched any of the wiring to the trigger or stator.
How could it possibly have changed its firing sequence from 1,2,3 to 3,2,1? In the manual it says the firing sequence is 1,2,3 and the night prior it started showing the timing correct according to the top cylinder? Anyway the engine seems to run fine although I have only ran it on the muffs so far and not WOT on the water yet. I am just very confused why the timing is showing as incorrect with the timing light on spark lead one, but showing as corerct on spark lead 3. Is it okay to continue running it like this?