Merc mariner 25 spluttering on pick up

[jwatson]

So having seemingly solved my blocked idle jet issue, the boat idles and seems to be ok flat out, but In between the two is far from ideal! As I increase the throttle it coughs and splutters before finally agreeing to increase revs! Could my mixture need addressing?

[uncle al]

Richen the idle air mixture to about one and a half turns out from lightly seated, if that is what it is set at now, richen the mixture by an other one quarter of a turn out from lightly seated. If its still the same are the sparkplugs the correct ones and is the gap correct?

[Fenlander]

As Uncle Al says....

Assuming plugs new(ish) and correctly gapped as a good starting point then idle mixture sounds weak (well it's the very easiest thing to sort and then if it's the same after ajustment look for the slightly more complicated stuff). There was a thread last year on this and the Mercury 15 2-stroke I bought about that time was set too weak at idle and did just the same on transition from idle to powering away. All sorted with the proper setting of the idle jet.

http://www.rib.net/forum/f36/2-strok...out-65026.html

[Nightfisher]

Tune-up time. If more, it will be detected during a scope connect.