Fishsqueezer
Cadet
- Joined
- Apr 5, 2012
- Messages
- 28
I?m working on a Mariner 50 hp, 4-cyl, 2 stroke, electric start, serial # 6542853
Here is a page from the Mercury service manual regarding timing for my engine. The table at top shows specifications.
Can anyone explain what the electronic timing characteristics are of this ignition system that require setting max spark advance at 32* BTDC to attain 30* BTDC spark advance?
Can anyone explain why the service manual would specifies setting Throttle Secondary Pickup at 33* maximum spark ?cranking engine with starter??
I?m confused as to why there would be any difference between cranking by starter or by combustion. Why not just scribe the flywheel appropriately for the correct timing? It seems somewhat convoluted to specify one number but say that setting should read another to attain specs. Seems like it should be simple enough, but it confuses me a bit. Only thing I can think of is that the flywheel was used in several models with different timing specs.
Any experts out there know why the manual specifies these things?
Here is a page from the Mercury service manual regarding timing for my engine. The table at top shows specifications.
Can anyone explain what the electronic timing characteristics are of this ignition system that require setting max spark advance at 32* BTDC to attain 30* BTDC spark advance?
Can anyone explain why the service manual would specifies setting Throttle Secondary Pickup at 33* maximum spark ?cranking engine with starter??
I?m confused as to why there would be any difference between cranking by starter or by combustion. Why not just scribe the flywheel appropriately for the correct timing? It seems somewhat convoluted to specify one number but say that setting should read another to attain specs. Seems like it should be simple enough, but it confuses me a bit. Only thing I can think of is that the flywheel was used in several models with different timing specs.
Any experts out there know why the manual specifies these things?
