60 HP Mercury 1992 upper engine wrist pin? noise

[buddhapi]

hi all. I got a 1992 60 HP Mercury 3 cylinder in today with a power head rattle. not bad, but it's there. I'm wondering if by chance carbon buildup on the pistons could make this? I once had a 440 big block Chrysler that had noise like this, and a sea foam clean out made that knock go away. it look's to me like the pistons are flat tops, unlike some of the domed Mercury's I'm used to seeing. any ideas are more than appreciated; Greg
Of course, it sounds like it could be a wrist pin rattle or maybe a cracked piston.

 

[Maxz695]

Re: 60 HP Mercury 1992 upper engine wrist pin? noise

True I had a 1969 chrysler 300 with a 440 in it. Sea foam is a great thing for cleaning out carbon deposits without dismanteling an engine. I would give it a shot, but I would not recommend running much more than idle until you find out if this is gonna work. It depends on how long the engine has been sitting and the fuel ratios that where used on this engine (NO ONE CAN TELL). If there has been water intrusion into the engine then I would suggest you get out your tool box and save whats left of the engine if possible. The lower seals could have gone bad the exhaust gasket could have gone bad. Not rinsing the engine in fresh water after a salt water run can corrode through many parts of the engine and plates

 

[Chris1956]

Re: 60 HP Mercury 1992 upper engine wrist pin? noise

Flat top pistons are used in loop-charged two cycle motors. The domes/deflector pistons are used in the cross flow and direct charge two cycle motors. Usually a rattle is not a good thing. You may try the seafoam, and hope it works, however, you will likely be disappointed. The noise could be piston slap or some kind of bearing noise.

 

[Faztbullet]

Re: 60 HP Mercury 1992 upper engine wrist pin? noise

These models are bad about the sleeves slipping if they have been overheated or lugged all the time. The sleeve will back out of cylinder and the crankthrows will hit it causing a metallic clacking noise, if it slips back to far the piston ring will fall behind sleeve and bust the piston. I rebuild 5 to 7 a year for this problem.

 

[buddhapi]

Re: 60 HP Mercury 1992 upper engine wrist pin? noise

the only confusing part to me, is that it doesn't show in the parts schematic that these are wet/replaceable sleeves. please indulge me some more.

 

[Faztbullet]

Re: 60 HP Mercury 1992 upper engine wrist pin? noise

is that it doesn't show in the parts schematic that these are wet/replaceable sleeves. please indulge me some more.

OEM does not offer sleeves just oversize pistons, sleeves are a machine shop repair not a DIY. Sleeves can be ordered thru Advance or LA Sleeve for nearly any 2 stroke on the market, and on these models I also pin them in place so this problem cannot reoccur.