finding tdc for timing

markhodges78

Chief Petty Officer
Joined
Aug 4, 2016
Messages
416
I have a 200 hp off shore carbureted engine SN 0G693618 . The boat is new to me and its not idling correctly. I know the P/O was a tinker because when I mentioned it he said you just have to adjust this screw a little and pointed to the max spark advance screw ... so before I go messing with anything I have some questions

1. How do I go about finding true tdc the manual says Turn flywheel in a clockwise direction until No. 1 piston is at top dead center set dial indicator at “O” (zero) and tighten indicator set screw... Ok did that but noticed the flywheel has a lot of movement on the rocker before it starts going down..
Turn flywheel counterclockwise until dial indicator needle is approximately 1/4-turn beyond .462 in., then turn flywheel clockwise so that dial indicator reads .462 in. (11.7mm) exactly. 4. Reposition timing pointer (a) so that timing pointer is aligned with .462 in. mark on timing decal. Retighten pointer attaching screws (b). 5. Remove dial indicator from cylinder..
So I'm assuming were only worried about .462 Correct which is wide open throttle ?

2. I still have the Idle Stabilizer Module Part # 87076A9 I've read that it might be a good idea to remove this Any thoughts? and this will change my timing setting so what should my new settings be and am I still marking .462 on flywheel or somthing else ... Right now they are
Maximum Timing: *(Models with Idle Stabilizer Module) @ Cranking Speed 22° BTDC
@ Wide Open Throttle 20° BTDC
Idle Speed/Pickup Timing 0°-9° ATDC ..

Thanks in advance
Mark
 

Dukedog

Captain
Joined
Oct 6, 2009
Messages
3,420
trash tha module.. jus make sure you end up with a short white/black jumper between tha bias post on tha switch boxes... once you get tha pointer set to tha .462 mark you can forget 'bout it... tha .462 will not come inta play settin' tha timing.... with advance timin' are at full advance, plugs removed and grounded set max at 22* and lock it down... done.
set idle with boat in water and in gear with idle timin' screw only.. set ta whatever makes you and motor happy... numbers on idle timin' make no difference.
 

markhodges78

Chief Petty Officer
Joined
Aug 4, 2016
Messages
416
trash tha module.. jus make sure you end up with a short white/black jumper between tha bias post on tha switch boxes... once you get tha pointer set to tha .462 mark you can forget 'bout it... tha .462 will not come inta play settin' tha timing.... with advance timin' are at full advance, plugs removed and grounded set max at 22* and lock it down... done.
set idle with boat in water and in gear with idle timin' screw only.. set ta whatever makes you and motor happy... numbers on idle timin' make no difference.
Thanks for your input ... helped alot apparently I was way off on the whole .462 idea...
 

Dukedog

Captain
Joined
Oct 6, 2009
Messages
3,420
with advance timin' "are" at full advance...

supposed ta be "arm"..
 

Dukedog

Captain
Joined
Oct 6, 2009
Messages
3,420
i'll try ta explain tha .462 deal.. when your at 0* top dead center there is still a little "play" back and forth.. when ya turn tha motor counter clockwise to tha .462 it eliminates all play in either direction and gives ya a hard number ta start with by setting tha pointer in tha right place ta read actual BTDC and ATDC numbers.. hope that helps......
 

markhodges78

Chief Petty Officer
Joined
Aug 4, 2016
Messages
416
i'll try ta explain tha .462 deal.. when your at 0* top dead center there is still a little "play" back and forth.. when ya turn tha motor counter clockwise to tha .462 it eliminates all play in either direction and gives ya a hard number ta start with by setting tha pointer in tha right place ta read actual BTDC and ATDC numbers.. hope that helps......
That makes all the since in the world no rocking....
 
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