Spark plug hole stripped

This evening I was putting in new spark plugs for the season. All of last years came out as easy as they should but when I tried put a new plug into #2 of my 80 KZ750, suddenly it will not screw in more than about 1/3 of the way without becoming very tight. Obviously I don't want to brute force it in there, is running a tap into it a good idea or no? If so how do I find what size tap to buy?

I tried brushing the threads out with a toothbrush but it was too large to fit. Also took one of those telescoping magnets & fished around but it picked up very little inside.

Make sure the treads on the plug are good. I had 1 that had a bugger in the threads and it almost cost me the plug hole threads. If you run a tap, use a reverse thread type. Starts at the bottom then comes up.

Plug threads are good, I ended up getting a reverse tap as recommended by Patton in a similar thread & it helped. Strange thing is I can get the plug in a turn or two at slight angles but then it stops, but going perfectly perpendicular to the hole as it was made took some finesse but made it all the way to the bottom. Even at max size the reverse tap easily went in & out by hand by the end of it.

oilynight wrote: Also took one of those telescoping magnets & fished around but it picked up very little inside.

Glad you got it working. Just wanted to point out about the above that if you were stripping your sparkplug holes, any debris from that would be aluminum, since that's what the engine block is almost certainly cast from, and aluminum isn't magnetic.

The old trick is to apply grease to the tap before running it through the plug hole. The metal particles adhere to the grease and come out with the tap.

There's no perfect way of getting the stuff out now without tear down, but you can go in with a brake bleeder. www.amazon.com/Mityvac-6830-Brake-Bleede...ty+max+brake+bleeder

It comes with a narrow tube you can use like a vacuum cleaner and suck stuff off the top of the piston.

VTEC wrote:
There's no perfect way of getting the stuff out now without tear down, but you can go in with a brake bleeder. www.amazon.com/Mityvac-6830-Brake-Bleede...ty+max+brake+bleeder

It comes with a narrow tube you can use like a vacuum cleaner and suck stuff off the top of the piston.

A vacuum/shop vac with the end connected to tubing with some ducttape works as well.