fastjeff
Gold Medal Contributor
Stumbled on this little trick today and, if you can't cure a bogging problem on your Merc, you might want to try this.
To wit: You slowly advance the throttle and--boggggg! Back down on the throttle quick so it doesn't stall, then try again: Another boggggg! Grrr! You add a bit of idle mixture (say, CCW a 1/4 turn) and that seems to help, but every now and then: Bogggg! Grrr!
On triples this is far more pronounced, possibly due to their 3 cylinders sucking through 2 carbs. I've struggled with this problem for years until trying the following: I drilled out the three holes in the butterfly (see photo) from about 5/64ths to 1/8 ". Didn't even have to pull the butterlies out to do it. And the result is fan-damn-tastic! The bog is virtually gone, even when the throttle blades are yanked open just above idle spark advance--try that without my modification and it will stall every time! Best of all, the idle speed and mixture settings seem to be about the same as before.
Jeff
To wit: You slowly advance the throttle and--boggggg! Back down on the throttle quick so it doesn't stall, then try again: Another boggggg! Grrr! You add a bit of idle mixture (say, CCW a 1/4 turn) and that seems to help, but every now and then: Bogggg! Grrr!
On triples this is far more pronounced, possibly due to their 3 cylinders sucking through 2 carbs. I've struggled with this problem for years until trying the following: I drilled out the three holes in the butterfly (see photo) from about 5/64ths to 1/8 ". Didn't even have to pull the butterlies out to do it. And the result is fan-damn-tastic! The bog is virtually gone, even when the throttle blades are yanked open just above idle spark advance--try that without my modification and it will stall every time! Best of all, the idle speed and mixture settings seem to be about the same as before.
Jeff
