OMG! is this my fault or AutoZone??? Wrong spark plug damages piston 88 special 1993

[toddschubert]

AutoZone now advertises we sell Marine parts.. So I needed some spark plugs after doing a carb cleaning and link and sync. I go to my trustee AutoZone and picked up the champion plugs I always use and install them after taking the old ones out and putting them all aside in my shop. When I got to the last one and tightened her up towards the end there was some resistance. I backed it out only to find it had gouged round hole at the top of the piston. Fearing this would create a hotspot I did not want to continue using the motor like it was. After trying to get some assistance to repair it from AutoZone who now is backing out from all responsibility, I took the head off to to find now, some pieces of ring in the cylinder that had been dancing around for some time. So that cylinder is shot. Rebuilt cost around $3000 and I found some used around 2000.

Does anybody have an idea or an opinion as to whether I should look for a power head only because my lower unit is in good shape or look for a whole new motor? what would be most cost effective to get my boat running again?

Whose fault do you think it ultimately is with the installation of the wrong plugs? my fault or the shop for giving me the wrong plug?

 

[racerone]

These motors break rings all the time !!!---Not the fault of Autozone at all.----Post the # of these " wrong plugs " if you like.

 

[toddschubert]

sorry for confusion. Two separate problems capt. to clarify spark plugs...I asked for the plugs for my motor and the guy looked it up on their computer and gave me a set of plugs. Asssumming they were correct and not having seen them side by side with the old ones, I had now way to know they were too long. While documenting the damage I found the ring pieces. Unrelated to plugs, the ring/s broke on that cyl.

 

[toddschubert]

auto Zone leagle dropped the case bc I didn't have reciept. We all knew I got the plugs there and they were the only ones of that mod the store sold all year. Damn technicalities

All I wanted was a little help with repairs....not whole thing. I was willing to accept some responsibility

 

[restornator]

seriously? i'm glad Autozone didn't get screwed

 

[itsaboattime]

Without sounding like an a$$hat, you should have compared the new plugs with the old ones before you installed them. I know, you trusted the employee who sold them to you. I get it. But here's the thing. That Autozone employee's job is to sell parts. It isn't his outboard that they are going into, it's yours. It is ultimately your responsibility to insure you are putting the correct part in your outboard.
If I sound like a jerk, I apologize. But you asked for opinions.

 

[toddschubert]

Yea, I get it...It's ultimately on me for being the last to touch them going in.
The part number is irrelevant, It was wrong! They have since fixed the computer error and it now shows the proper plug.
The broken ring is a coincidence if you read

 

[emdsapmgr]

Hard to tell just how bad the hole/dent is on the piston crown without an attached picture. The larger and primary problem is the cracked ring failure. Actually, that's a larger problem and will require a complete teardown and some degree of overhaul. Usually when a ring goes (a common failure in the V4 crossflow engines) it will usually do significant damage to the piston crown and the face of that head. That's on your nickel. Likely not a spark plug problem-or you would have the same problem on the other 3 pistons also. Since you are headed to a teardown anyway, it's a opportune time to replace the damaged piston. Time to move on into the repair/fix-it mode. You need to hone all 4 holes and install 4 ringsets, in addition to the piston. Also-you'll need to determine the reason for the ring failure before you run it again: piston ran hot, ran lean? Was it a restriction in the carb throat that feeds that cyl? Damaged water deflectors in the head? Stuck thermostat?

 

[rickryder]

Always compare your parts before installing. .. kinda like checking the gap on pre gapped plugs....

 

[tpenfield]

Sure AutoZone gave you the wrong plugs, but you put them in. . . so in 'he who touched it last' rules of responsibility you should feel responsible (sorry to say).

Most folks on this forum who change spark plugs will tell you that they usually compare the new plug to the old plugs just to make sure they have the same thread size/depth.

 

[Chinewalker]

If Autozone installed them, that would be one thing, but you installed them, so the fault is on you. Other than some carbon being removed from the dome by the plug tip, I find it hard to believe that simply installing them would damage the piston to the point where you wouldn't run it. The piston should give/move before real damage is done. In the end, it is up to you to know that your motor calls for QL77JC4 Champions, or whatever the equivalent is in your brand of choice.

 

[racerone]

Here is the way I see it.-------Motor was running poorly due to broken piston rings / bad compression.----Owner tried to see if new sparkplugs would correct running issues. ---Wrong plugs had nothing to do with damage to the motor !!!!!!!!!!!!

 

[toddschubert]

racerone,
that's exactly what happened. I have stopped collection activities but am still very frustrated at AZ. They had a problem, acknowledged it then refused to help fix issues that problem created. Bottom line I guess is my motor had pre disclosed greater damage that trumps the spark plug issue so I let it rest.

 

[boobie]

What plugs did you have in it and what plugs did AZ give you ??

 

[gm280]

Okay after read all the comments and the OP's story. My question is how hard did you try to turn them in? Once the plug hit the piston, you should have felt a huge amount of resistance and stopped, knowing something was royally wrong. Plugs don't get torqued to 100 ft/lbs but mere very little. So I can't see how you didn't know they were hitting and therefore punched a hole in the top of any piston... That takes some serious torque! Usually I install plugs with fingers (where I can ready them) and then give them a slight tightening with about a 60 degree further turn...that's it! They either come with a crush metal seal ring, or are tapered to seal... It doesn't take much to reach their proper tightening torque... JMHO! And I certainly mean no offense in my comment...more wonderment then anything else.

 

[toddschubert]

after finger tightening and encountering resistance that seemed to be normal I put a wrench to it as normal but it turned too much to be normal tightening. I backed it out to find the anode had bent off to the side and piston was scarred.
AZ computer had wrong part number listed for that motor. They corrected it now but didn't even thank me for being the guinea pig.

 

[toddschubert]

I'm wondering if $2000 sounds high for a used motor with good compression (88spl '94)

 

[toddschubert]

Sure AutoZone gave you the wrong plugs, but you put them in. . . so in 'he who touched it last' rules of responsibility you should feel responsible (sorry to say).

Most folks on this forum who change spark plugs will tell you that they usually compare the new plug to the old plugs just to make sure they have the same thread size/depth.

I would disagree that most people hold the old and the new side by side and measure the length before installing when they bought the plugs for that motor. It's definitely a good idea though...as I have learned. Don't trust anybody- that's a shame

 

[racerone]

Very hard to find a 25 year old clerk at "parts store " with 40 years experience in marine engines.-----These people only know how to push a button on a computer and go to a shelf.------Fellow at my NAPA store said to me " here is the catalogue , you know what you need to look up.----I do not know much about marine stuff "

 

[restornator]

AZ doesn't list part no.'s. They list reference numbers or stock numbers. J4c plug is 825 for example. Still a plug didn't puncture the piston.