Mac Spark Plug Gapping Tool

[Mr Tiger]

I've just bought a Mac spark plug gapping tool from a well respected engine builder and tuner. It arrived this morning in the post. It doesn't look like any other gapping tool I've seen and came with no instructions. I've worked out how to open up the gap - and it's very good at doing this. I can't see how to close up the gap - which is what I really need it to do. I don't really want to resort to the hit and miss method of tapping / hitting the outer electrode.

Does anyone have one of these and know how to use it?

Regards,

Chris

[one eyed mick]

Whats wrong with feeler gauges ? the tapping bit has worked for over century !

[Doctor Volt]

A good spark plug gapping tool has a slot cutout that fits around the outer body electrode and is used to lever that electrode as required

[Doctor Volt]

Below is a link to a pdf file that shows the proper tools for the job

http://www.ngkplugpro.ca/en/techbulletin_detail.ph...

[Mr Tiger]

Thanks for the replies.

I'm not keen on the tapping method. I usually tap too lightly at first, then try to hit it slightly harder and end up closing the gap too much.

The slot type tools I've bought before have been of very poor quality and wear out almost as soon as they're first used. I hadn't (back then) seen any of good quality.

The Mac tool is £12 inc postage. It seems to be of good quality. I'd assumed (wrongly) it would be a slot type, just better made and with a long arm for some leverage.

I tried using a vice to gently close the gaps on some plugs this afternoon. The first one went well, got it just right first time. The second one went badly - closed the gap up too much. The Mac tool wasn't much use, it was really difficult to grip the outer electrode with the gap too tight.

I'll e-mail the supplier and ask him how he uses it. Perhaps I'll look around for a decent quality slot type tool. Can anyone recommend one?

Thanks again,

Chris

[DocArbathnot]

Seems to be getting a bit.........erm......................anal (assuming this is for the Vixen running a Triumph engine)