Attention:Tighten your plugs

[DeusEx]

This is just a warning to everyone who changed their spark-plugs recently.
I got my bike back from the mechanic yesterday.
About 2500 km after I changed my plugs with iridium plugs, I drove to my work and after 20 km of regular driving, the spark-cable from the 2nd cylinder pop-ed out. I tried to put it on again but it kept popping out.
The mechanic said that the threads from the spark-hole on the cylinder head got stripped.The reason was that the sparks were not sufficiently tightened.

After a week and 300 euros poorer, I got my bike back, fixed.

Check your plugs, tighten 'em down according to specs.

FYI

 

[FinalImpact]

^^
+1 for the shop who did the original work to pick up the tab on this one. . .

Essentially if they couldn't be trusted to tighten one of the 4 bolts (spark plugs) properly, they owe you.

Sorry to hear about that. Did they put a Heli-coil in it? As the only other options that come to mind are an insert, welding it up and tapping, and head replacement.

Just curious...

 

[Black_Cirrus]

For cars the "proper repair" from most manufactures is an insert kinda like a helicoil but it is one piece of steel you over drill and tap the hole, glue in with special epoxy, then take special tool to flare the top out to help keep it from backing out.

 

[04fizzer]

^^
+1 for the shop who did the original work to pick up the tab on this one. . .

Essentially if they couldn't be trusted to tighten one of the 4 bolts (spark plugs) properly, they owe you.

Sorry to hear about that. Did they put a Heli-coil in it? As the only other options that come to mind are an insert, welding it up and tapping, and head replacement.

Just curious...

It sounds to me like he did the plug replacement himself.

 

[616ah]

For cars the "proper repair" from most manufactures is an insert kinda like a helicoil but it is one piece of steel you over drill and tap the hole, glue in with special epoxy, then take special tool to flare the top out to help keep it from backing out.

I personally on a high performance application would not use a threaded insert for a spark plug. Inserts can change the way the plug transfers heat considerably. Not good. I also just don't trust the things to stay in long term as most inserts on the market are flawed in design IMHO.

After years of ford truck plugs ejecting with stripped threads ford authorized using an insert that seems to be somewhat acceptable.

In addition (aside from torquing properly ) I recommend taking care to ensure that NO dirt is between the spark plug seat and the head as that can be responsible for starting the loosening process.

My 2c FWIW.