merc 200 hp outboard ,broken connecting rod

[kenthrussell]

Hi I bought this boat 2yrs ago and the end of last summer replaced head gaskets and impellar,When I removed one head I noticed that all cylinder walls were chrome but one that had been sleeved with a cast sleeve, recently went out this year and clunk a rod went through the block,this was the one with the cast sleeve, now is there a heat transfer problem here using a cast sleeve as opposed to the chrome? is this likely the reason this cylinder went? so now i am looking at a new power head (rebuilt)mmmmm expensive too i might add!<br /><br />------------------

 

[12Footer]

Re: merc 200 hp outboard ,broken connecting rod

Ouch

I feel your pain! In answer to your<br />question,yes. I beleive the heat tranfer is thrown way off by using a cast sleave,unless all the jugs are sleaved the same. And even then, not properly.<br />If I bought an new engine, I'd probably void the warantee, but I would dern-sure do away with oil injection. After all the recalls and powerhead failures relative to the newer designs, you would think engineers would "just say no", and keep it simple.<br /><br /><br />------------------<br />Water,water everwhere...And all I can catch is CATFISH!!!

 

[ODDD1]

Re: merc 200 hp outboard ,broken connecting rod

Replacing a damaged chrome sleeve with a iron liner is the factory recommened method of repairing these blocks...there are thousands of iron sleeve V-6 motors running around out there with NO 'heat transfer' problems...instead of looking at the first 'different' thing you see and pointing the finger of blame, ask your self, was the problem that destroyed it the first time fixed? Was the crank journal wrecked last time and somebody rebuilt the crank,and journal failed kicking the rod? Was the rod over stressed at the last failure, causing the breakage? Any recent "tune up" work done?<br />As an aside...I think oil injection has done more for engine longevity than any other single improvement..the only people that consistently fail merc's oil injection routinely exceed maximum RPM's.

 

[MERCMAN]

Re: merc 200 hp outboard ,broken connecting rod

I've built a lot of 2.4 chrome bore V-6 in my time and never had a problem with using steel sleeves.Now I've seen a cylinder not live long if the wrong rings are used or the sleeve was installed wrong. What does the piston look like is the top eaten away or is it scuffed on the sides which cylinder is it.Which end of the rod failed if the crank end failed you probably got a piece trash in the bearing and caused the bearing to start sliding instead of rolling seen that a few times. As for the oil injection Mercury's been running this system since the early 80's never seen a pump go bad except for the problem with the seal behind the pump and the oil gear on crank stripping and most the time that was caused by a stuck check valve or the engine had been overheated a few times and became brittle.

 

[MERCMAN]

Re: merc 200 hp outboard ,broken connecting rod

My thoughts exactly ODDD1. You beat me to it I can't type as fast as you.

 

[kenthrussell]

Re: merc 200 hp outboard ,broken connecting rod

probably right about being installed improperly , as i don't know the history on the motor,could have went to an oversize piston or whatever, thanks for the replys