Hi all, I know this is unrelated to the gp but was wondering if anyone could help, I took my spark plus out my r6 the other day, The 1st, 2nd and 4th came out easy but the 3rd... No! It would loosen of then suddenly get really tight again and then wouldn't go any further, so I tightened it back up and left it but now all of a sudden it's got a slight hiccup at low revvs, I'm not saying it's that plug but I want to change them all but can't get the 3rd out. Anyone had this issue before? Before any suggests it I have warmed the bike up first then tried to take the plug out but no joy.
Cheers in advance.

A common problem if the plug is slightly longer than the thread n the head, is that it sticks a thread or two into the combustion chamber. This gets coated in carbon and acts like a threadlock.

Look at the three that come out and see if the last thread or two is dirtier than the majority. If it is, this is a likely cause. To get it out, you will have to persevere. Turn it until it starts to get stiffer. Retighten only a few degrees, then out again by that amount or a bit more, repeat. Like two steps forward, one back. This will gently force the carbon deposits to cut a thread or break away. A common trick with rusty bolts.

Be gentle, don't break the plug. They can be fragile as the metal body is not very thick, especially on the tiny plugs in bikes. Penetrating oil around the plug may help, but it has a long way down to go. Plus-Gas, not WD-40.

Presumably it has been too long since they were last removed.

Cheers mate, il give it a try tomorrow afternoon, I did try and turn it the other day and it felt like I was turning for ages even while it was getting tighter but then it just stopped completely. Il do what you said with the penetrating oil, what would you recommend? I do recall the bottom of the threads were black because at first I thought it was oil :/ but it wasn't so I was happy with that!

Apologies in advance , I've just re-read it and noticed you said plus-gas! Sorry for my incompetence

Turn it out as far as you can. Squirt the plus-gas in. Go have a cup of tea, cut the lawn, etc. Come back, tweak it each way a little bit at a time. Add more plus-gas, repeat until successful/bored/fed up/in tears. (Delete as applicable, or add own)

portland_bill said:

Turn it out as far as you can. Squirt the plus-gas in. Go have a cup of tea, cut the lawn, etc. Come back, tweak it each way a little bit at a time. Add more plus-gas, repeat until successful/bored/fed up/in tears. (Delete as applicable, or add own)

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You sir are a legend! I did exactly as you said and it's now out. So I thank you for your advice as now I can sort it!.

Well done, glad its worked.
Are they identical ones to OE, or have you replaced NGK with Denso or vice/versa? Sometimes replacements can be just a thread or two longer, or they may be intended to project in to the combustion chamber. In future, pop them out a little more regularly, to ease the job.

I've not replaced them yet, il be putting standard ngk ones in. I may put a bit of cooper grease on the thread to to prevent it stick so much. Tbf I have had the bike 3 years and only done 5k on it and only just serviced it :/ so partially my fault.

Yep, a smear of copper grease on the thread will help. Just a smear, not a big dollop.
Then make a note to pop them out annually, even if only to put them back in again.

portland_bill said:

Yep, a smear of copper grease on the thread will help. Just a smear, not a big dollop.
Then make a note to pop them out annually, even if only to put them back in again.

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makes you question the wisdom of "long-life" plugs in cars,
could be a head-off job every 50K,

Charlie

Mrs. Beard's 156 has long life plugs, 3 years or 100,000 miles. They came out ok because our mechanic checks them even if it's not time to replace. Ergo, no sticky plugs.