mercruiser 3.0 lx

[sf43]

owned this for two years runs great very smooth and fast trouble is when i first purchased i did tune up plugs oil etc noticed plug in cyclinder 1 porcelain cracked, wrote off changed now winterizing went to fog cyclinders same plug cracked again any ideas on why this cyclinder is cracking porcelain all others are fine need help to correct situation as boating season will be back soon!!!!! thanks mike

 

[mr300z87]

Re: mercruiser 3.0 lx

This past spring when I was tuning my 3.0l up, and while I was tightening #4 the porcelain broke and of corse I had some choice words. What I believe happened is I angles the socket in a way that put too much pressure on the porcelain part of the plug. Was much more careful with all the rest and the new one. Just a thought.

 

[achris]

Re: mercruiser 3.0 lx

owned this for two years runs great very smooth and fast trouble is when i first purchased i did tune up plugs oil etc noticed plug in cyclinder 1 porcelain cracked, wrote off changed now winterizing went to fog cyclinders same plug cracked again any ideas on why this cyclinder is cracking porcelain all others are fine need help to correct situation as boating season will be back soon!!!!! thanks mike

Mike,

You might like to try and put some punctuation in your post. I took one look at that lot up there and decided to pass it by, as a lot of regulars here are doing. If you want answers to your questions, make it easy for folk to read....

Please take this in the spirit it is intended, not as an insult.

Chris.......

 

[CharlieB]

Re: mercruiser 3.0 lx

Depends upon which side of the porcelain is cracked, inside or outside of the cyl.

Outside is caused by handling during installation/removal.

Inside can be caused by detonation or possibly water intrusion, thermal 'shock' of a water droplet contacting the hot glass.

Verify ignition timing.

Compression test, to ensure that cyl is the same as all others.

Pressure test exhaust manifold.