Author Topic: Broken Spark plug (Read 7644 times)

kawasutra · « **on:** 10 October 2015, 05:18:42 pm »

Got 3 out and replaced and the last one just snapped with the first attempt at turning the wrench to get it moving. Gutted!

Anyone broken it a similar way and managed to get it out without going the long route?

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Paulfzs · « **Reply #1 on:** 10 October 2015, 07:12:34 pm »

iridium sparkplugs

they last forever!
last years before they need to be removed...

then this happens.

cant you get anything inside it and turn it?

kawasutra · « **Reply #2 on:** 10 October 2015, 07:18:07 pm »

Hehe! I bought normal NGKs off ebay to replace whatever last owner had put in.

I want to remove the front fairing inside panel to get straight line access into the recess before attempting anything.

Also, saw a post in this forum about using a torx bit but the pic isn't there so can't see if it was a similar break to mine.

I need advice but perhaps a pic of what remains in the recess would be useful.

Quote from: Paulfzs on 10 October 2015, 07:12:34 pm

iridium sparkplugs

they last forever!
last years before they need to be removed...

then this happens.

cant you get anything inside it and turn it?

Paulfzs · « **Reply #3 on:** 10 October 2015, 07:20:50 pm »

ive not seen inside a broken spark plug but if it has a hole in it, get a torx bit of around the same size but a little bigger and hammer (gently) it into the hole and then unscrew it.

Torx bits are pretty good for most damaged screws and such because it has many edges to grip with.

kawasutra · « **Reply #4 on:** 10 October 2015, 07:23:25 pm »

This is the thread: http://foc-u.co.uk/index.php/topic,1160.msg7847.html#msg7847

I will remove inside panel in the morning and report back, but torx bit idea most promising at the moment.

Cheers!

Paulfzs · « **Reply #5 on:** 10 October 2015, 07:59:02 pm »

yeah same as i said pretty much.

dont hit it hard itll destroy the thread

Val · « **Reply #6 on:** 10 October 2015, 08:26:09 pm »

Quote from: kawasutra on 10 October 2015, 07:23:25 pm

This is the thread: http://foc-u.co.uk/index.php/topic,1160.msg7847.html#msg7847

I will remove inside panel in the morning and report back, but torx bit idea most promising at the moment.

Cheers!

I would try torx. Probably good idea to use WD40 or penetration fluid before that.

I have used torx twice so far for stuck bolts. One time was radiator 4mm Allen bolt chemically bound and stuck. I've used T25 which is 4.43mm and a hammer. Soaked it with penetration fluid. Embedded the torx well and than just slight tughtening to break it and than slight untighten. Than again slight tighten and again untighten. It broke well. Than just unscrew.

Measure the hole and See Torx sizes:

https://en.wikipedia.org/wiki/Torx#Sizing

Bretty · « **Reply #7 on:** 11 October 2015, 03:18:47 pm »

When the plug snaps like that I think it leaves the threaded part in the engine with it's ceramic core. Be carefull when whacking anything down the middle of the plug that you don't push that bit of ceramic into the engine.
I've heard people suggest that if you turn the engine over the pressure should blow that ceramic core out.

If you can get that ceramic bit out of the middle, I would be tempted to attack it with a torx bit in an impact driver with lots of penetrating fluid or get an easy-out on it.

Either way give it a good soaking in penetrating fluid as your plug looks well corroded.

Alternatively if you take the head off (a bit more of a ball ache than it sounds) you'll be able to unscrew the plug from the other side with some long nose pliers.

If you ever do get the old bit of plug out, don't forget the spark plug washer which might still be in the top of your engine!

kawasutra · « **Reply #8 on:** 11 October 2015, 04:45:17 pm »

It's a pretty hard to reach recess for the plug.

My plan is to order some easy outs from screwfix, a long thin drill bit and a lot of penetrating oil.

Soak in oil for 24 hours and then try to drill a pilot hole in the middle of the remaining plug, then get the easy out onto it.

The little metal washer came off with the broken bit, but am still weary of getting anything into the cylinder.

Not an advanced bike-tinkerer so doing a lot of reading and you tube viewing before going for it.

Paulfzs · « **Reply #9 on:** 11 October 2015, 04:48:51 pm »

hex bit extension bar is all you need to reach in there.

http://www.ebay.co.uk/itm/QUICK-RELEASE-1-4-HEX-FLAT-WOOD-BIT-EXTENSION-EXTENTION-300mm-LONG-/301688363654?hash=item463e071a86

kawasutra · « **Reply #10 on:** 11 October 2015, 04:56:06 pm »

This is how it looks. So there is no hole to get a torx into and turn. Pilot hole and then easy out extractor?

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plug hole1

davey boy · « **Reply #11 on:** 11 October 2015, 05:37:00 pm »

I hate easy outs never once got them to work as they expand the bolt they are extracting which you don't want to do and a guy at work snapped one in the same situation you are in and then you can't drill the hardened easyout then it was a head off job
I would try the torx method if I where you

Paulfzs · « **Reply #12 on:** 11 October 2015, 06:52:43 pm »

Oh i see! i thought it was hollow inside!

drill a pilot hole and try a torx bit, if it fails try easy out.

plenty of penetrating fluid (not wd40) and a little heat may help.

Banging the torx bit in may loosen the seal a little which will help.

sinto · « **Reply #13 on:** 11 October 2015, 07:31:19 pm »

I'm not sure of what the inside of a spark plug is like tbh but as you've got one out already, why don't you cut across it and try drilling that in a vice etc first before you try and drill the one out in situ?

You may be able to drill small pilot holes as suggested already but try and do a couple or three in a row and get a screw driver into it and unscrew it that way?

Bretty · « **Reply #14 on:** 11 October 2015, 10:32:52 pm »

You won't drill through the middle of the spark plug! It has a ceramic core. Harder than any drill bit. With a very small metal part going through the middle of that

You'll drill through the metal, but as soon as you hit the ceramic the drill will just spin in the hole.

Bretty · « **Reply #15 on:** 11 October 2015, 10:38:43 pm »

http://www.fordanglia105eownersclub.co.uk/images/tech/tech-plug02.jpg

maniaka · « **Reply #16 on:** 12 October 2015, 01:56:20 am »

Hey dude sorry this has happened to you - a real ball ache.

Same thing happened to me !

I used a ceramic drill to drill out as much of the spark plug as I need to allow an easy out to grip the metal thread.
Soaked with penetrating spray overnight and a few other occasions.

Then I used an easy-out. it worked but was lucky, non of the garages wanted to touch it without taking the head off and drilling it out.

Tip 1) Pre drill it, otherwise you will struggle to get it to bite however only drill what you need - don't want swarf in the cylinder
Tip 2) Go slowly when using the easy out - they blunt real quick and you only get a couple of shots.

Worst case scenario ... you dont drill enough and you snap the easy out as you turn it too fast !

But it is possible to get out .. heres mine using a halford easy out [second to largest size from memory]

Bretty · « **Reply #17 on:** 12 October 2015, 10:01:47 am »

Good effort getting that out!

Your photo shows the ceramic core only just held in place by the electrode.
That's the bit you need to be careful doesn't drop into the engine, when you drill or insert the easy-out.

kawasutra · « **Reply #18 on:** 12 October 2015, 10:22:50 am »

Quote from: Paulfzs on 11 October 2015, 04:48:51 pm

hex bit extension bar is all you need to reach in there.

http://www.ebay.co.uk/itm/QUICK-RELEASE-1-4-HEX-FLAT-WOOD-BIT-EXTENSION-EXTENTION-300mm-LONG-/301688363654?hash=item463e071a86

Paul, do I need this to drill a pilot hole? I'm assuming that it's needed to get past the frame and into the recess.

kawasutra · « **Reply #19 on:** 12 October 2015, 10:23:36 am »

Quote from: sinto on 11 October 2015, 07:31:19 pm

I'm not sure of what the inside of a spark plug is like tbh but as you've got one out already, why don't you cut across it and try drilling that in a vice etc first before you try and drill the one out in situ?

You may be able to drill small pilot holes as suggested already but try and do a couple or three in a row and get a screw driver into it and unscrew it that way?

I thought of this idea but do not have a work bench or a vice at hand. I will see if my neighbour is willing to let me try this on his vice.

kawasutra · « **Reply #20 on:** 12 October 2015, 10:27:13 am »

Quote from: maniaka on 12 October 2015, 01:56:20 am

Hey dude sorry this has happened to you - a real ball ache.

Same thing happened to me !

I used a ceramic drill to drill out as much of the spark plug as I need to allow an easy out to grip the metal thread.
Soaked with penetrating spray overnight and a few other occasions.

Then I used an easy-out. it worked but was lucky, non of the garages wanted to touch it without taking the head off and drilling it out.

Tip 1) Pre drill it, otherwise you will struggle to get it to bite however only drill what you need - don't want swarf in the cylinder
Tip 2) Go slowly when using the easy out - they blunt real quick and you only get a couple of shots.

Worst case scenario ... you dont drill enough and you snap the easy out as you turn it too fast !

But it is possible to get out .. heres mine using a halford easy out [second to largest size from memory]

Thanks man. Only last week I started riding regularly to work and really enjoyed the commute. Met a few bikers on the road as well and was starting to get ready for riding through winter! So yeah, massive ball-ache it is.

I appreciate your suggestions on this and am encouraged by your success.

I have ordered a set of easy out extractors from screwfix as well as 2 cans of penetrating oil. I have a car to use so will soak the hole in oil from tuesday evening every day till I get to work on the bike on Saturday.

Also waiting for the long hex bit Paul has recommended to get the pilot hole drilled.

I really want to get it sorted as this bike has some sentimental value and it's just bloody good fun riding it!

Deefer666 · « **Reply #21 on:** 12 October 2015, 05:44:39 pm »

I'd just whip the head off and wind the fucker out from the bottom, Half a days work. Job done!

His Dudeness · « **Reply #22 on:** 15 October 2015, 11:42:47 am »

Quote from: Deefer666 on 12 October 2015, 05:44:39 pm

I'd just whip the head off and wind the fucker out from the bottom, Half a days work. Job done!

Me too. The only dodgy part would be getting the exhaust off without snapping studs. If you take the head off you'll get a look at the head, cam chain and cylinders. You could do the valve clearance as well while you're at it. Maybe a carbie clean too while they're off.

kawasutra · « **Reply #23 on:** 15 October 2015, 11:52:06 am »

Quote from: His Dudeness on 15 October 2015, 11:42:47 am

Quote from: Deefer666 on 12 October 2015, 05:44:39 pm
I'd just whip the head off and wind the fucker out from the bottom, Half a days work. Job done!

Me too. The only dodgy part would be getting the exhaust off without snapping studs.

The exhaust header pipe nuts/bolts are pretty rusted so I'd like to try and get this done without having to attempt removing those rusty bastards!

Penetrating oil put in yesterday and will do again today and tomorrow and Saturday attempt the extractor route.

I might still end up having to remove the head!

limax2 · « **Reply #24 on:** 15 October 2015, 05:06:21 pm »

Interesting that this topic should crop up now as for the first time ever a spark plug has just broke on me. It's on a 1974 Triumph Trident that has been laid up for about 20 years. As you can see the insulator has all come away so just the threaded part is left behind in the head with a neat hole in the centre. I did consider going in with a left hand tap but since the head will be coming off anyway I will attack it from the inside.

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