Helicoil question

[jamesrs250]

i need to repair my spark plug thread i have the right size helicoil M10 x 1.00. i need to know what tap size and drill size i would need to use. i have the tool and brerak pin tool from a kit i used before.

[ZebraDriver]

Helicoils have a special tap because the size and thread pitch do not match standard engineering stuff. An online search should get you the info you need for both the tap and the drill.

ZD

just did the search for you 10.25mm tap drill and a helicoil tap 4984-10

[Fizzer Thou]

Here you go

https://www.ebay.co.uk/itm/Thread-Repair-Kit-Helicoil-Inserts-M10x1-0-/330647454735?pt=UK_Hand_Tools_Equipment&hash=item4cfc1fc40f
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Just talk bikes.What else is there?

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[jamesrs250]

thanks

i have a m10x1 tap

but only a 10.5mm drill bit

so will have to find a 10.3 bit from a tool shop becuse 10.3 is a bit of a weird size dont think you would find a 10.3 from b&q

[Fizzer Thou]

https://www.ebay.co.uk/itm/EXPERT-10-3mm-HSS-TWIST-DRILL-HELICOIL-THREAD-REPAI-/400205902643?pt=UK_Home_Garden_PowerTools_SM&hash=item5d2e217333
____________________
Just talk bikes.What else is there?

Always have a 'Plan B'

[jamesrs250]

thanks agen,,, i allready found them on ebay..i just wanted to do it tomorow

[jamesrs250]

i have done some more searching and asking people who sell helicoils and alot of them dont know 100% if they are the same tap size as a normal tap or the say they are

one seller who sounds like he knows 100% said

Hi,

Yes they are oversized to allow for the insert. An M10 1.0 helicoil tap has a diameter of 11.3mm

[craigT19]

Hi,

Helicoils are ok but tbh are not particularly suited to a spark plug thread, with the high pressure plus the chance your be taking plugs in and out over time the coil will loosen so its more of a medium term fix. Hellicoils also dont sit flush to the head, if your plug is slightly counter sumk it will sit ontop of the hellicoil altering the plug heigh within the combustion chamber.

Personally i use timeserts, there stronger sit within the current damaged thread and once in perminent. A timesert kit can be an expensive item however, but the kits ive seen all come with the taps and drills your need for that particular timesert

https://www.wurth.co.uk/time-sert.php
https://www.youtube.com/watch?v=pLVDb0xcvMo
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Bikes owned :- 2001 nsr125, 1999 zx6r, 2006 yzf-r1, 2009 xmax 250, 2012 yzf-r1, 2015 MT-07
Current bike : - 2016 MT-10
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[ZebraDriver]

Perhaps the fact that the tapping drill is bigger than the thread size being used i.e. a 10.25 drill for a 10mm thread should alert you to the fact that the heli-coil insert (and thus the tap) HAS to be bigger than the 10mm plug that you are fitting and that an ordinary M10x1.0 tap is not suitable for use when fitting heli-coils.

Even without the info I gave you you must be able to work out (fairly easily) that the insert must be a bigger diameter than the plug that you are going to fit into it.

Please don't bother asking for info on here if you are not intelligent enough to use what people provide.

[bencav]

[MickC]

[Ed Case]

A Helicoil will 'do' for a spark-plug hole reclamation but on recommendation I've had a 'Timecert' fitted in my 250RSA cylinder head. In the past I've had Helicoils come out with the bolt, probably a cock-up when being fitted but nevertheless they did come out. Best of luck whichever you decide upon !.