motor knocking

[hollandcrew]

I have an 1985 Mariner 90 hp inline 6 cyl. I was running about 25 mph all of a sudden motor started knocking, I thought It had blowed up. I came back down to idle (still in gear)motor still knocked. I took It out of gear motor still knocked. I sayed what the heck If It's blowed I'm going to run back in. I gave It some throttle motor stopped knocking. So anyway to sum up the problem the motor will knock like its blowed then it runs just fine. It has done this to me 3 times.<br />Help!<br />AL

 

[kev_79]

Re: motor knocking

Be weary...The inline Merc's don't have a head seperate from the block, so if there is trouble with the pistons, you could be beating up the head area, and if it's bad enough, you will have to replace the block. <br /><br />The only way to inspect a merc without breaking it apart is to take off the exhaust plate and look into the exhaust ports for trouble.<br /><br />Let us know what you find.<br /><br />k