Spark Plug won't screw in properly..!?!

[infiniteloop]

Decided to change my spark plugs the other day after an oil & filter change. All went well until i took the bike a run & it was running like a bag of bolts. On further inspection I discovered one of the spark plugs wasn't seated at all properly (the one 2nd from left as you sit on the bike) so I took it out & now I can't get it to seat, it goes in at a slight angle & only screws in partially. It seems to me that the threads are crossed but I cannot get it to line up & seat as it should…any advice or recommendations as to my next move would be appreciated…cheers

[Paulfzs]

I had this issue like 3 days ago..


get a bottle cleaning brush...


air compressor if you have one if not one of those cans of air that you use to clean dust, some wd40...


blow all the dirt out near the plug which there is always loads of due to a bad design...


soak the brush in wd40 stick it in the hole and push it up and down and turn it around...


spray some wd into the hole to make sure its all come out brush it some more..


cover new plug in oil and try again...


brush can be bought from poundland, they have a big end and a small end on them, small end fits fine.

[Val]

After you do the cleaning that Paul suggested you may buy spark plug thread chaser you need 10mm one

http://www.sparkplugs.co.uk/thread-chaser-10-12mm

Very carefully with WD40 clean the thread with the chaser back and forth.

[wickedmonkey]

Hi Val,

How carefully is very carefully? Only I think I have a cross thread as well.

Thanks,

David.

[infiniteloop]

Thanks for the advice gents..got one of those bottle cleaners, soaked it in WD40 & was giving it plenty down the cylinder when the brush came off the handle..! Nearly lost it down the cylinder but managed to get it back. Anyway..now the spark plug is going down a bit further but still seems to be cross threaded. Local bike shop can't take it in for another week so will report further then, though the mechanic told me it'll probably need re-threaded. Oddly enough the bike now sounds much better..does the spark plug need to be fully seated to fire properly..?

[Paulfzs]

how tight does it feel?


mine felt tight but i was like.. well if its knackered itl need a helicoil so i carried on, it wasnt tight tight but it felt like it was half a turn off being fully tightened and i got about 2 more turns and it was seated.


tip


put your finger on the drain hole on the side of the cylinder and spray some wd40 round the plug and start the bike,  itll bubble if theres a leak.


im not saying do it but all i did was carried on tightening it up and now the threads fine.

[infiniteloop]

It feels pretty tight but clearly not fully seated. I'm now thinking I may as well tighten as much as I can..if the thread is knackered now then it'll have to be redone anyway. As i said, the bike sounds a whole lot better now so i'll have another look at it & try to squeeze another turn or 2. Can the helicoil/re-tapping be done without taking off the cylinder head..? How much should I expect to pay to have my local bike mechanic do the job..?

[Paulfzs]

helicoil isnt too hard, it can be done with the engine as it is but if the tang breaks off it could be a pain getting it back out...


the swarf just blow out with an air compressor.


id say an hour or so job so £50 ish?

[red98]

Mmmmm......dont think you'll get all the swarf out with compressed air, if that was me I would take the head off, ok your going to need a new £30 head gasket but if you fit the helicoil yourself its a cheaper fix than using a garage, only takes a small amount of swarf to damage the bore......

[Val]

Hi Val,

How carefully is very carefully? Only I think I have a cross thread as well.

Thanks,

David.

Hi David,

Find a mechanic that has done that. It is not hard but it helps if the person doing that has an experience.

When I say carefuly I meant do 2-4 turn forward than remove the thread chaser and clean.

The exact procedure is here:

http://www.carsdirect.com/car-repair/how-to-use-a-spark-plug-thread-chaser-engine-ignition-repair-tips

cheers
Val

[Val]

It feels pretty tight but clearly not fully seated. I'm now thinking I may as well tighten as much as I can..if the thread is knackered now then it'll have to be redone anyway. As i said, the bike sounds a whole lot better now so i'll have another look at it & try to squeeze another turn or 2. Can the helicoil/re-tapping be done without taking off the cylinder head..? How much should I expect to pay to have my local bike mechanic do the job..?

Before you resort to radical solution as helicoil have you tried the thread chaser?

Also I would not do a helicoil. Much better solution would be Wurth Time-Sert system. Only if you really need rethread solution though.

[infiniteloop]

Ideally I would take the head off but a mechanic I'm certainly not.! Happy to do self-maintainence jobs like oil changes, filter changes, sprockets & chain etc..but the thought of taking the head off is a scary prospect for me. Wish I had the techy knowledge & confidence though.!

[Bretty]

I have an engine head sat outside my house. I was going to replace a broken exhaust stud on it and sell it on ebay.
It doesn't have the cams or cam covers but the rest is in good condition. I'm open to offers, cash on collection in NW London, if you're interested?

Brett

[unfazed]

I have an engine head sat outside my house. I was going to replace a broken exhaust stud on it and sell it on ebay.
It doesn't have the cams or cam covers but the rest is in good condition. I'm open to offers, cash on collection in NW London, if you're interested?

Brett

Paper weight without the cam cover/caps, machined as a unit in the factory

[Paulfzs]

I have an engine head sat outside my house. I was going to replace a broken exhaust stud on it and sell it on ebay.
It doesn't have the cams or cam covers but the rest is in good condition. I'm open to offers, cash on collection in NW London, if you're interested?

Brett

Paper weight without the cam cover/caps, machined as a unit in the factory

^this


they come as a set and if split are pretty much useless.

[darrsi]

I have an engine head sat outside my house. I was going to replace a broken exhaust stud on it and sell it on ebay.
It doesn't have the cams or cam covers but the rest is in good condition. I'm open to offers, cash on collection in NW London, if you're interested?

Brett

Paper weight without the cam cover/caps, machined as a unit in the factory

^this


they come as a set and if split are pretty much useless.

Really that bad?

[Buzz]

I remembered that "Thorn" had the same problem a few years ago.

http://foc-u.co.uk/index.php/topic,8581.msg85271.html#msg85271

[Paulfzs]

I remembered that "Thorn" had the same problem a few years ago.

http://foc-u.co.uk/index.php/topic,8581.msg85271.html#msg85271

thorn never stops having problems with things like this.


hes got a zx9 c2 with a knackered box, heard a z1000 box fits so bought it changed to find output shaft lengths are much different.


hes powering through though.

[His Dudeness]

You could salvage the valve assemblies and shims out of the head if they're in good nick