Magneto/Timing Adjustment on Mariner 40HP Please help! Bogging High RPM'S

PatrickMonahan

Seaman Apprentice
Joined
Feb 3, 2016
Messages
47
I have a 40HP Mariner 6E9 engine and it runs very well up until high RPM'S at WOT and bogs down, I observe that when I put it into gear it moves a bit, the linkage to shoves the magneto linkage moves up a small bit( fully advanced in youtube video below) and it does not continue to move as the accelerator or throttle is increased to WOT. IN the video I have included it shows the boat at full throttle with the engine off, what I was wondering was if it( timing/magneto linkage) did not advance enough at high RPM'S could this cause it to struggle and stutter at high revs. Could do with a few opinions thanks. Basically I think its not in sync Thanks
 
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GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
The timing advances as the motor is throttled up until it hits the max advance stop.

Are the carbs fully open at WOT?
 

quicktach

Petty Officer 1st Class
Joined
Aug 24, 2012
Messages
394
Clean and lube all linkages and where advance slides. I'd pull flywheel and clean under it. Also watch out that
wiring isn't limiting movement of advance mechanism.
 
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