Club 80-90 Forums

The worst has just happened checking the gaps on the plugs C.U 2.0 Aircooled 3 came out no bother the last bugger was tight and decided to drag out a couple of threads from the bottom of the hole

I've tried the reverse Sealey reverse action spark plug thread chaser to no avail

I have used the Helicoil on inlet manifold so familiar with the procedure doe anyone know the exact Helicoil that is required for the head (spark plug hole) on the 2.0 CU? I don't want to get this wrong and upon looking on the net there are many sizes and styles does anyone have previous expirence with this they can help me with my choice would be most appreciated

Regards to All Alan

Standard M14x1.25 x 19mm (3/4") spark plug thread. I prefer inserts rather than Helicoils for plug repairs, less chance of winding in a helicoil into the combustion chamber when you change a plug.

bigherb wrote:Standard M14x1.25 x 19mm (3/4") spark plug thread. I prefer inserts rather than Helicoils for plug repairs, less chance of winding in a helicoil into the combustion chamber when you change a plug.

Dude you have done it again thanks for the info you helped us last time and it worked a treat thanks Bigherb a credit to the site.

Northfalia wrote:

bigherb wrote:Standard M14x1.25 x 19mm (3/4") spark plug thread. I prefer inserts rather than Helicoils for plug repairs, less chance of winding in a helicoil into the combustion chamber when you change a plug.

Dude you have done it again thanks for the info you helped us last time and it worked a treat thanks Bigherb a credit to the site.

Would you know where I can get the exact kit from I am just looking but can't seem to find it sorry for being a bit dumb but I'm always over cautious when it comes to important stuff like this regards

This the sort of thing you need preferably the tap needs a reamer or stepped thread so the tap goes in straight. This was the first one I came to with the right sort of tap, there are loads on ebay some of them much cheaper.

http://www.ebay.co.uk/itm/14mm-SPARK-PL ... XG2xvZiQbQ" onclick="window.open(this.href);return false;

By the way it is advisable to do this with the head off otherwise use lots of grease to hopefully stop the swarf entering the cylinder.

Hi Herb thank you for the help it's a daunting one I was afraid I would have to remove the head because of the swarf entering the cylinder head.

Is it just a matter of loosening the head bolts in sequence then it slides off? Then refitting it's a sequence with a torque wrench? Never done anything to this scale before I am quite confident I am a stickler for getting it spot on and won't attempt it unless I know the ins and outs of completing it correctly

sorry for all of the questions I don't have any other friends technically minded for assistance

Regards Again Alan

Northfalia wrote: Is it just a matter of loosening the head bolts in sequence then it slides off?

Yes undo the head bolts in reverse sequence to the tightening sequence.

Ok seems simple enough I'm just looking in the Haynes now and it is talking about sealing rings ?? Does this need doing?

One big question does the engine need to be removed for this procedure? Or can I just get away with stripping the tinwear carbs and exchanger?

Looks like I'm a busy lad next week

Just need to man up and get the spanners out ha

Get the engine out, big herb will keep you right. Engine out is a doddle.

Northfalia wrote:Ok seems simple enough I'm just looking in the Haynes now and it is talking about sealing rings ?? Does this need doing?

One big question does the engine need to be removed for this procedure? Or can I just get away with stripping the tinwear carbs and exchanger?

If it has sealing rings then replace them, replacement heads have a different sealing arrangement and may not need them.
It is best to remove the engine, but if your pushed for space it can be done by just swinging the engine down on the front gearbox mounting.

Ok thanks for the help Bigherb

I am going to remove the everything in the way inlets carbs air box tinwear etc and carefully do the repair in situ using plenty of grease to catch the swarf as previously mentioned. I have a Hoover tube Small enough that will fit into the spark plug hole to remove any bits that get away from the grease

I just think it's a massive upheaval to start removing the head plus I don't want to get into disturbing it until a rebuild in the future.

I will take some photos of the repair to add to this thread to help others

Watch this space thanks again for the help I'm just waiting for the inserts to arrive so I can get started

E D I T

Air cooled.