Problem with Spark Plug, won't fit in.

[ktm301p]

Hi all,

I removed the spark plug from my motorbike this morning as a new one is needed. There was no problem with removing the plug as it came out nice and smoothly like it should. However when I went to put in the new plug, I find I can do a quarter turn with my fingers before it locks completely and won't go in any further.

I have tried a few tricks of the trade such as putting some grease on the thread, and turning the plug anti-clockwise to try and feel for the thread but the damn thing still won't screw in. I don't want to try and turn it past the locking point in case of ruining the thread.

It will be ages until I can get access to a van or trailer to get it down to a garage so would would like to do something about it myself.

Any advice or tips would be greatly appreciated

Thanks
Alex

[stevieturbo]

Get someone more experienced to inspect the thread before you do damage. Although it may already be damaged. A quick visual should be all that's needed really.

[The_Burg]

It is the same type of plug? I believe some are tapered and some are straight.
If it was a tapered hole and a straight plug it would give the symptom you describe, (or i may be talking b0llo0x).

[stevieturbo]

Ive never seen a tapered thread plug, but absolutely there are different thread sizes etc.

If the thread is largely ok and undamaged, this style of tool is the best option.

Obviously order the tool for the correct thread used

http://www.ebay.co.uk/itm/Sealey-MS003-Reverse-Act...

[mrmr96]

Sounds like the new one has a different pitch to the thread. Hold it up next to the old one and try to align the peaks of the threads and see if they stay lined up the whole length of the thread.

[freecar]

The_Burg said:

It is the same type of plug? I believe some are tapered and some are straight.
If it was a tapered hole and a straight plug it would give the symptom you describe, (or i may be talking b0llo0x).

Tapered? On what??

[mrmr96]

freecar said:

The_Burg said:

It is the same type of plug? I believe some are tapered and some are straight.
If it was a tapered hole and a straight plug it would give the symptom you describe, (or i may be talking b0llo0x).

Tapered? On what??

The threaded bit basically being the shape of a wine bottle stopper:

Ensures a better seal (maybe) because it seals on the threads rather than the base.

[TheEnd]

Does the old one fit back in?

[ktm301p]

TheEnd said:

Does the old one fit back in?

The old does not fit back in, nope.

[ktm301p]

stevieturbo said:

Get someone more experienced to inspect the thread before you do damage. Although it may already be damaged. A quick visual should be all that's needed really.

I drove down to a local garage this evening, the mechanic said there is a chance that I was being too gentle and maybe I just need to use a bit more force. I'm going to try and take it down there this weekend, providing I can get access to my mates van and if I can get there before going back to Uni on Sunday

[blitzracing]

Get the old plug, and carefully cut a slot at 90' to the thread with a hack saw down as much of the thread as you can. make sure you have no burrs, the thread it back in the plug hole. Whatever is jamming the thread will end up in the slot, so go carefully and it cleans things up nicely without buy a special tool.

[phumy]

blitzracing said:

Get the old plug, and carefully cut a slot at 90' to the thread with a hack saw down as much of the thread as you can. make sure you have no burrs, the thread it back in the plug hole. Whatever is jamming the thread will end up in the slot, so go carefully and it cleans things up nicely without buy a special tool.

And if youre not too sure about doing this then dont as you could fk the whole thing up completely and end up needing new a thread.

[ktm301p]

phumy said:

And if youre not too sure about doing this then dont as you could fk the whole thing up completely and end up needing new a thread.

Unfortunately I fall into that category

[ktm301p]

I was unable to get the bike down to the garage, but hopefully this will be fixed next time I'm down. ( mid-April )

[blitzracing]

phumy said:

blitzracing said:

Get the old plug, and carefully cut a slot at 90' to the thread with a hack saw down as much of the thread as you can. make sure you have no burrs, the thread it back in the plug hole. Whatever is jamming the thread will end up in the slot, so go carefully and it cleans things up nicely without buy a special tool.

And if youre not too sure about doing this then dont as you could fk the whole thing up completely and end up needing new a thread.

If you cross thread it then yes you will mess it up, but as long as its square and has started in the thread for the first few turns then it wont do any harm( a lot less harm than trying to force the new plug back in if there is muck / distortion in the threads). The trick is to use a bit of lube and go carefully. If it jams up, screw it back out and inspect whats in the slot. If its full of aluminium its time for profesional help however.

[freecar]

mrmr96 said:

freecar said:

The_Burg said:

It is the same type of plug? I believe some are tapered and some are straight.
If it was a tapered hole and a straight plug it would give the symptom you describe, (or i may be talking b0llo0x).

Tapered? On what??

The threaded bit basically being the shape of a wine bottle stopper:

Ensures a better seal (maybe) because it seals on the threads rather than the base.

Now show me a tapered spark plug...

I've never seen one and google didn't show me one either.

A tapered spark plug is one that has a tapered seat not thread, you can recognise these because they have no captive washer as it is the taper of the seat that seals the head, not the crush of the washer.

[mrmr96]

freecar said:

mrmr96 said:

freecar said:

The_Burg said:

It is the same type of plug? I believe some are tapered and some are straight.
If it was a tapered hole and a straight plug it would give the symptom you describe, (or i may be talking b0llo0x).

Tapered? On what??

The threaded bit basically being the shape of a wine bottle stopper:

Ensures a better seal (maybe) because it seals on the threads rather than the base.

Now show me a tapered spark plug...

I've never seen one and google didn't show me one either.

A tapered spark plug is one that has a tapered seat not thread, you can recognise these because they have no captive washer as it is the taper of the seat that seals the head, not the crush of the washer.

I've not seen one either, but was just clarifying what the other guy was saying. I've used tapered fittings as described for things like fitting sensors into oil systems though.

[garagewidow]

this may explain,

http://www.sparkplugs.co.uk/pages/technical/NGK-sp...

[Evoluzione]

ktm301p said:

Hi all,

I removed the spark plug from my motorbike this morning as a new one is needed. There was no problem with removing the plug as it came out nice and smoothly like it should. However when I went to put in the new plug, I find I can do a quarter turn with my fingers before it locks completely and won't go in any further.

I have tried a few tricks of the trade such as putting some grease on the thread, and turning the plug anti-clockwise to try and feel for the thread but the damn thing still won't screw in. I don't want to try and turn it past the locking point in case of ruining the thread.

It will be ages until I can get access to a van or trailer to get it down to a garage so would would like to do something about it myself.

Any advice or tips would be greatly appreciated

Thanks
Alex

Please post up the part number of the old plug and the new one.

[ktm301p]

Evoluzione said:

Please post up the part number of the old plug and the new one.

The old and new spark plug definitely have the same code/ part number. I am unable to get the specific number though because I am up at University at the moment, and the SP is at home!