new Mercury ob question

[Ed Michrina]

I purchased a Merc. 15 hp. 4 stroke this year. I broke it in per instructions. The question is, after running approx. 1 min in full throttle I get a knocking noise in the motor. Almost like a backfire. All I have to do is back off the throttle the slightest and the noise go's away. I have tried 87 and 98 oct. gas and it doesn't make a diffrence. Is this something that can be adjusted or should I take it back to the dealer? or is this something that will go away or something I'll have to live with? Thanx.

[Gone Fishing]

It sure doesn't sound right to me Ed and being a new motor, I certainly wouldn't live with it.

[ESOX]

Doesn't sound good to me either Ed.
I'd take it in....................or
Drop it off at my house and go get a new one.;)

[TONGA]

:mad: I can't belive you have not taken it back yet

[FishTales]

I would have taken it back a long time ago, I have 75 hp 4 stroke and there is no knocking noises in mine.

[Ed Michrina]

I have only had it for 3 wks. It's going back . Thanx everyone.

[captain jay]

Where do you buy 98 octane gas? I want some of that for my boat:D

Captain Jay

[Ed Michrina]

ooops 89 good one captian. lol