Valve hitting spark plug...?

[hooooolt]

Anyone have an issue with this?

I installed this ignition kit on my xs2:
https://www.mikesxs.net/xs-charge-xs650-ultimate-high-output-ignition-system-70-72.html

While troubleshooting some starting issues I took out the plugs, and the right one looked like it had been hit by the cylinder or something. There was a small sliver of metal missing off of the side electrode right at the end and it was also bend down to the point that it was in contact with the center electrode. I honestly wasn't sure if maybe it was dropped or something so I re-gapped the plug and popped it back in. After cranking her over I took the plug back out and it was fouled up a bit but had a fresh scuff on the same spot. From the angle, I am suspecting it's the valve striking it? I can post photos tomorrow if needed, but has anyone ever come across this? I looked in the forums and haven't seen anyone report it.

They are the NGK BPR8EIX Iridium Spark Plugs, which (after checking) are longer than the ones I had in before, but they are the ones everyone seems to be using on here with the PAMCO and dual output coils. Are there spacers that everyone is using?

Thanks for any thoughts,
Holt

 

[TwoManyXS1Bs]

Haven't heard of that on here as of yet. I'd be wanting to flashlight into the sparkplug hole, while slowly rotating the engine, looking for matching scrape marks.

A bit on the Iridium plugs.
http://www.xs650.com/threads/nkg-iridium-spark-plugs-bpr7eix.48251/

Plug indexing entertainment.
Post #10 has my comments on clearancing.
http://www.xs650.com/threads/indexing-spark-plugs.48354/

 

[grizld1]

Sounds like a piston smacked the ground strap of the plug. So four questions. First: what shorter plugs came out of there? Second: Has the deck been lowered to raise compression? Third: Have aftermarket pistons with high domes been installed? Fourth: Are the valves standard size or did somebody stick big 'uns in there? I gotta say this is a strange one, I've dropped the deck by as much as .030" and had no problem running NGK BP7ES, which put the plug nose and ground strap in the same place as the iridiums you used. Also odd that it's happening only on the right side. I'd want to take a look at the valves and see if a pair of collets did a comealoose or if a valve is stuck open. You might want to pull the valve covers and watch the action while the motor is turned over by hand.

 

[hooooolt]

Thanks for the responses. I'll check what the removed plug is, but the engine is entirely stock. Nothing has been altered and it's got 13k miles on it with no real issues. I'm doing all of this work in a an airplane hangar and the mechanics helped me inspect the engine with a video scope. We couldn't identify any damage on the valves or cylinder from the video feed. I'm sure its there somewhere, but the plug is a softer metal so it may have been the only one to take a hit.

It's odd... but the next thing I'm going to do is double check that the plug is seated between 3 and 6 o'clock. Maybe see if I can get a slim shim to change the seat position. From reading @toomanyxs1bs threads, it sounds like that might help. The thing that is weird is that nobody else has had this issue...

Haven't heard of that on here as of yet. I'd be wanting to flashlight into the sparkplug hole, while slowly rotating the engine, looking for matching scrape marks.

A bit on the Iridium plugs.
http://www.xs650.com/threads/nkg-iridium-spark-plugs-bpr7eix.48251/

Plug indexing entertainment.
Post #10 has my comments on clearancing.
http://www.xs650.com/threads/indexing-spark-plugs.48354/

Sounds like a piston smacked the ground strap of the plug. So four questions. First: what shorter plugs came out of there? Second: Has the deck been lowered to raise compression? Third: Have aftermarket pistons with high domes been installed? Fourth: Are the valves standard size or did somebody stick big 'uns in there? I gotta say this is a strange one, I've dropped the deck by as much as .030" and had no problem running NGK BP7ES, which put the plug nose and ground strap in the same place as the iridiums you used. Also odd that it's happening only on the right side. I'd want to take a look at the valves and see if a pair of collets did a comealoose or if a valve is stuck open. You might want to pull the valve covers and watch the action while the motor is turned over by hand.

 

[TwoManyXS1Bs]

.. the next thing I'm going to do is double check that the plug is seated between 3 and 6 o'clock...

For the right plug, I'd have the plug gap between 6 and 9 o'clock...