Coughing at Low Revs

[jimbojambo]

Hello there

I have got a Mariner 15M (2 stroke) and it's a great little engine for my purposes and goes very well on a SIB.

The only thing (well, *nearly* the only thing ) that is not quite right is that it coughs at low revs from time to time, and the revs drop momentarily as a result. They are back up within a split second, but it isn't right. At high revs it's spot on and runs well. It also occasionally stalls when dropped into neutral, which I guess could be linked.

Since my 20 mile trip today when it must have coughed about 20-30 times, I've done some research and my guess is the low speed needle/screw needs to be opened up a tad more. It was at 1 & 3/4 turns out and I've taken it up to 2. I also took it out and gave the hole a blast with carb cleaner, in case there was some crud in there too.

I know time will tell and my next trip will be the ultimate judge, but I am wondering if the consensus is that this is a good starting place?

Thanks in advance to any replies from the pros!

James

[Seabay]

I have a Johnson 15hp 2 stroke.
The last time we took it out it had "sneezes"
it turned out to be a blown exhaust gasket which cost £7 fitted.

[jimbojambo]

Without meaning to ask a stupid question, is a "cough" the same as a "sneeze"? I could well have used the wrong word to describe it...

It was a sort of popping noise (I could have imagined it, but I thought I saw a puff of smoke too - which could well be exhaust related). Isn't the exhaust gasket a pig to get to?

Cheers
James

[uncle al]

your problem sounds like a carb problem (a bit of dirt/water) they dont sudenly run lean for no reason