Merc Timing

[FredM]

Just checked the timing (at cranking speed) on my '81 Merc 18. Timing light shows about 4 deg too advanced at WOT (29/30 BTDC instead of 25 - 3 punch mark on flywheel). <br /><br />Trouble is the trigger linkage is as short as it will go and I need to shorten it to retard the timing. Is there anything else in the trigger area that could cause the timing to be too advanced?<br /><br />The motor starts and runs fine with no detonation under load.<br /><br />Thanks in advance

 

[FredM]

Re: Merc Timing

^

 

[Mikael-Block]

Re: Merc Timing

Hey FredM<br />Ref. manual, you have to check if the marker is aligned propably... Check if it macht TDC.<br /><br />Then you have at asure that linkage is on the marks...<br /><br />Timing is ajusted in FWD.<br /><br />But follow manual, point by point...othervise it is hard to ajust probably<br /><br />The engine can be damaged if timing is wrong<br />Mikael

 

[FredM]

Re: Merc Timing

Thanks for your reply Mikael, I do have a manual and the timing sequence is straight forward enough. The timing mark in the 18 is not adjustable though. It is a line cast into the rope start housing so the timing mark is not an issue as with other merc models.<br /><br />It's really a matter of adjusting the trigger link so that at WOT the timing is 25 BTDC. It's also a couple of deg too advanced at idle. <br /><br />Seems curious to me that the trigger link is already as short as it will go. <br /><br />My question is is there another condition in any of the other ignition components (like wear etc) that could have caused the timing to advance?<br /><br />Thanks