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Overtightened Spark Plug
Posted: Fri Aug 28, 2015 12:50 pm
by knowledge boy
Yesterday I replaced the spark plug, today I broke down, I removed the new plug and found that it had been flattened and (by the piston I assume). The bike won't start with the old plug in, it struggles to turn over with a lot of clanking noises. have I done goofed?
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 12:55 pm
by Jge64
are you saying the piston collided with the spark plug?
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 1:01 pm
by knowledge boy
I'm guessing so as the damage looked mechanical
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 1:04 pm
by Jge64
Yeah, this is either the piston being connected incorrectly or the wrong plug installed (too long)
I would say a dealer visit is next.....
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 1:06 pm
by gn2
What plug did you fit and what was the original plug?
If the replacement plug was too long and the piston has hit it, your engine could be toast.
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 1:14 pm
by knowledge boy
NGK CPR7EA-9, got it from a Honda dealer,
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 1:23 pm
by knowledge boy
Here are the plugs, new and old
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 1:32 pm
by Jge64
Wow....thx for the pics, keep the recept for the plug, you may have a case if its the wrong plug....
Do they (or did they) look to be EXACTLY the same length?
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 1:40 pm
by gn2
If the new plug is the same model as the old plug and the one you got is definitely marked on the plug as the right one, (not a wrong one in the right box) I don't see how overtightening it could have got it far enough into the cylinder for that to happen.
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 1:43 pm
by knowledge boy
Jge64 wrote:Wow....thx for the pics, keep the recept for the plug, you may have a case if its the wrong plug....
Do they (or did they) look to be EXACTLY the same length?
I am 90% sure they were the same length, I have put my tools away for now, and the old plug is in the bike, I will take it out and compare what is left of them later.
Re: Overtightened Spark Plug
Posted: Fri Aug 28, 2015 1:58 pm
by knowledge boy
gn2 wrote:If the new plug is the same model as the old plug and the one you got is definitely marked on the plug as the right one, (not a wrong one in the right box) I don't see how overtightening it could have got it far enough into the cylinder for that to happen.
I followed the instructions in the user manual, 1/2 a turn, loosen then 1/8 of a turn.