Crossed thread

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nathan5346

Well-Known Member
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Location
oldbury
Finally got round to servicing the mota but.......had trouble getting a spark plug out, found it was cross threaded ive managed to get a plug in after bostin 1 and the mota runs well but i dunt think its seated right.... is there an 'easy' solution/ :(
 
when you use it, turn the tool anti clockwise and you should feel edge of thread.
When your happy you have it at correct angle-turn clockwise.
If it goes tight while cutting thread-turn half a turn back and try again.
Disconnect plug leads and spin over-should blow swarf out of cylinder-may be wise to keep an extra plug in case any remaining swarf fowls plug later on.

Go steady with it or yor be having to heicoil or timecert it=head off
 
when you use it, turn the tool anti clockwise and you should feel edge of thread.
When your happy you have it at correct angle-turn clockwise.
If it goes tight while cutting thread-turn half a turn back and try again.
Disconnect plug leads and spin over-should blow swarf out of cylinder-may be wise to keep an extra plug in case any remaining swarf fowls plug later on.

Go steady with it or yor be having to heicoil or timecert it=head off
theres already 2 threads in it :( neither one looked like the plug was seated correctly but both accepted the plug only got hard to turn with a few turns left, just had a mad dash to m/mart... dint make it lol, i'll let ya know how i get on
ta :)
 
the important thing is get the angle right and go steady, unless it's beyond redemption, 90% of the time you can run tap through it.
 
the important thing is get the angle right and go steady, unless it's beyond redemption, 90% of the time you can run tap through it.

Stick a dod of grease on it that usually catches the swarf, but as fanatic says take your time it must be in line. Sometimes a little tap on the end of the tap as you turn it if it goes off square will tru it again. Make sure the piston is a bit down the bore anorl.

If its fooked it aint such a problem putting an insert into it, just another tap and a doodah that screws in with a bit of thread lock using a spark plug.
 
To save the head, and if you're NOT sure about it, pull the head and put the chaser or an M14 X 1.25 tap in from the cylinder side, you'll get a good start and it will be centred by the time the tap gets to the top.

I know it sounds a lot of work, but the head is awfully easy to damage, and once you've done the damage, you'll have to pull it anyway.

Did this for a friend a month or so back, he had a mate helping him who screwed the plug back in cockeyed and wound it in with the socket :eek: He got the head off and we recovered the thread. I've got both a proper machine tap and a thread restorer if you get stuck, can post them up if you need them.

Use a smear of Copaslip on the threads when refitting the plugs.

Peter
 
i agree with lister

a better chance of saveing the head and the threads that way, plus its out and you guarentee no swarf in the cylinder that can cause damage.

trust me its worth it in the long run.
 
I can see the sense with what you've said lister but i also have the lpg system on that side to contend with anorl... so im in a bit of a dilema :(:(
 
Didnt fancy the head off so got the chaser and decided to have a go with the head insitu, gotta say that chasers a good bit of kit, the plugs seated as it should and all is good, its been a bit of a pain tbh... thats the thanks u get for keeping ya mota serviced and maintained....Thanks for the help n advice guys its appreciated ;) :)
 
Didnt fancy the head off so got the chaser and decided to have a go with the head insitu, gotta say that chasers a good bit of kit, the plugs seated as it should and all is good, its been a bit of a pain tbh... thats the thanks u get for keeping ya mota serviced and maintained....Thanks for the help n advice guys its appreciated ;) :)

I like happy endings:cool:
 
A good tip, Get a old spark plug remove the porsolene , put two hack saw lines at the botton of plug and you a ready made tap . I have used mine for many years.:D
 
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