Heli-coil Spark Plug hole question

Hey folks,
On my 78 KZ650, the #2 spark plug hole threads don't look too good. I may have to heli-coil it. Normally, this is a head off operation I would think. However, pulling the head is going to be a disassembly I really wish to avoid. Funds to replace all the gaskets and such that go along with it, plus the time, make this an difficult option to take.

So, I was thinking about another option and I thought I'd run it past you guys, since you are the real experts, and see if it's a reasonable idea.

I was thinking I could rotate the engine to where the #2 exhaust valve is open. Then, stick my air compressor hose up the muffler and bascially be blowing as much air as I can out the spark plug hole to help blow out any metal chips as I perform the heli-coil operation. Additionally, liberally grease up the tap and stuff to try and catch as many metal chips as possible.

Well, that's the idea. Any feedback on whether you think this would work sufficiently to keep enough chips out of the cylinder would be helpful. Or, any other experience proven ideas on how to heli-coil the spark plug hole without having to remove the head, without thrashing the cylinder in the process, would be appreciated.

Thanks,

Terry!

u can buy a kit at an auto suply store for this. it has a tap and an insert, not a coil. u just grease up the tap and thread it in by hand then u thread the insert in ,and u are done. now for the nitty gritty stuff. just turn the tap a little at a time then remove it, and remove all the metal filings from it then repeat till done.then u will have to chamfer the top of the hole so the insert, wich has a lip on top, will sit down flush on the head.some kits have a tool for this or u can turn a large drill bit by hand.then try to find someting u can put down the hole and remove the burr at the bottom, that is left by the tap exitting the bottom of the hole. now u clean the threads with brake cleaner or something, then loctite the incert into the hole with red or green,not blue.

I've come across a better solution if the head is not too boogered up. See this thread and then decide if it might work for you. In both of the bikes I used it on it was the easy answer.

Back Tap

Good find Gringo