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Opinions & Feedback - Cross Brands Thread.....

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eneusiis

Regular Contributor
Sorry, I know this doesn't belong here, but the topic I think is brand agnostic and you guys have helped me so much over the years. This is posted in the Mercury form, but value your feedback in here as it is a cylinder issue, which can happen to any make and is most likely a ring job or cylinder honing job. Any feedback here or over there I would greatly appreciate. Trying to help my father with as much information as possible.

http://www.marineengine.com/boat-fo...ke-EFI-Cylinder-damage-and-thoughts-on-repair
 
Not sure what you're asking. First thing is to remove the cylinder head and assess the damage. This was definitely caused by detonation or pre ignition and internal damage probably more severe than a quick hone.
 
Agree with detonation occuring. This cylinder looks to have gone very lean at off idle rpm.

You can look with borescope or flex cam and cell phone. Don't be surprised to find hole in, or major damage to, piston crown and unrepairable cylinder wall scoring.

The head combustion chamber may have also been damaged beyond recovery as well.

Sorry for the bleak outlook but that's my guess as to what you're likely to find.
 
jgmo said:
Agree with detonation occuring. This cylinder looks to have gone very lean at off idle rpm.

You can look with borescope or flex cam and cell phone. Don't be surprised to find hole in, or major damage to, piston crown and unrepairable cylinder wall scoring.

The head combustion chamber may have also been damaged beyond recovery as well.

Sorry for the bleak outlook but that's my guess as to what you're likely to find.
Click to expand...


So is the root cause really a failing injector versus a faulty plug or a combo of both?
 
I don't have an answer for you but if your motor takes the NGK LFR6A-11 plugs then according to the E3 sparkplug web site they do not have a plug for that application.

You might want to check the spec's on the E3 plugs the parts guy provided if possible.
 
The only way that I can see a spark plug "grenading" like that one did, and it be the plug's "fault", is if it is the wrong application for the engine and is contacted by the piston or a valve because it is too long. Otherwise, I think you would have possibly had the plugs "glowing" and causing preignition but you would see all the plugs damaged in a similar way.

As alumarine points out, it may be the wrong application but I don't see evidence of contact on the other plugs.

I do see that the plug adjacent to that one appears to have sustained a bit of damage as well. That is unless I'm looking at shadows in the photo.

Yes, I suspect the injector causing this rather than the spark plugs.

Just my opinion.
 
jgmo said:
The only way that I can see a spark plug "grenading" like that one did, and it be the plug's "fault", is if it is the wrong application for the engine and is contacted by the piston or a valve because it is too long. Otherwise, I think you would have possibly had the plugs "glowing" and causing preignition but you would see all the plugs damaged in a similar way.

As alumarine points out, it may be the wrong application but I don't see evidence of contact on the other plugs.

I do see that the plug adjacent to that one appears to have sustained a bit of damage as well. That is unless I'm looking at shadows in the photo.

Yes, I suspect the injector causing this rather than the spark plugs.

Just my opinion.
Click to expand...


Thanks for the responses. You can see the one of the far left was in the process of melting the tip. I did go look at e3's website and there is no cross reference equivalent to the NGK for the motor, they even prompt a window telling you that. I tried looking up their outboard plugs and it only has marine plugs up to 50 hp for Mercury. O'Reily's system of cross reference plugs cannot be correct.
 
jgmo said:
The only way that I can see a spark plug "grenading" like that one did, and it be the plug's "fault", is if it is the wrong application for the engine and is contacted by the piston or a valve because it is too long. Otherwise, I think you would have possibly had the plugs "glowing" and causing preignition but you would see all the plugs damaged in a similar way.

As alumarine points out, it may be the wrong application but I don't see evidence of contact on the other plugs.

I do see that the plug adjacent to that one appears to have sustained a bit of damage as well. That is unless I'm looking at shadows in the photo.

Yes, I suspect the injector causing this rather than the spark plugs.

Just my opinion.
Click to expand...

UPDATE:

Just coming around full circle on this one: O'Reily's system in fact had an incorrect cross-reference plug listed. There is only the NGK - LFR6A-11 that should be used and one other NGK predecessor. They had an e3 plug, those in the picture that is rated for a 50HP merc, not a 115HP merc listed and sold my father.

The porcelain and chunks of metal took a chunk out of the valve. The engine is getting new valve and short block. O'Reily's thus far is standing by their mistake and is most likely reimbursing my father for the repairs.
 
Great news for your dad! Except for all the hassle and loss of use this year that is. He may end end up better off in the long run.

Kudos to Oreilly's for admitting their error and stepping up.

I can only surmise that they see signs of pre ignition caused by the plugs.

But, hopefully, you won't "experiment" by using the same injectors again.

Good luck.
 
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