ABN Spark Plug Thread Repair Kit, 14mm Reamer Cylinder Thread Repair Tool & Thread Insert – Spark Plug Rethreader Kit

I stripped a spark plug thread on my Kawasaki 21hp engine on my 2006 Ferris zero turn mower. I first tried a 14mm thread chaser but spark plug would not tighten, so I purchased the ABN repair kit with reamer and inserts. I removed all cylinder shields from engine (Still mounted on mower) so I could get a good look at the spark plug hole. I had to use a 1/4" battery powered impact to be able to get the reamer to start cutting for the plug insert. I covered the reamer with grease and when it started to cut the new threads I then used a 1/2" ratchet to slowly cut the threads. I removed the reamer/threader after about 2 turns and cleaned the grease and cuttings off, repeating this until the new threads were completely cut, then I cleaned the new threaded hole in the head. I then screwed the proper insert onto the new plug until it bottomed out and put red thread lock compound on the outside of the insert and screwed the spark plug with the insert on it into the head and tightened the plug to seat the insert. I removed the plug and the insert was completely seated. I then reinstalled the new plug and tightened to specs. The engine runs properly now and I mowed about 2 acres with it. The only downside is there is no instructions with the kit, that is why I wrote this long review. I can recommend this kit for anyone that strips a spark plug hole.

Since there is a bunch of commentary on this product, wanted to add mine. I was weary with the purchase after reading the poor reviews, but glad it all worked out. It was cheap, but it did the job on my 1970 Chrysler Outboard Head. I was only going to use the inserts but found they weren’t going in straight…so I used the tool, and was able to improve the threading and it goes in straight now. Just go slow, use grease to clean up the shavings and back out if you think you aren’t doing it right or well. Check to see if it’s good to add the plug and insert…then lock it in. I would definitely buy again and recommend.

BE WARNED - KEEP LOOKING because you get what you pay for. If you plan to use this on wood it might be worth the investment.I've been a shade tree mechanic for many years, and have tapped a number of things so I'm used to the concept. I bought this tool to re-thread the aluminum 50cc head. I started out by drilling the hole out to 9/16 even though you aren't supposed to be required to do that unless tapping iron. With the head in a vice (removed from the engine of course) I tried to get the tap started using a socket wrench and it would bite, and then get cocked to one side or the other. I tried and tried to keep this thing straight to no avail. After several attempts, the tool became harder and harder to use. Checking out the tap, I saw that the first few rows of threads were either non existent or nearly worn flat. This thing is garbage "metal" or has a poor temper/heat treat that won't even stand up to aluminum.I ran to the auto parts store for another kit costing twice as much that worked perfectly. The problem is two fold, poor metal quality so it won't hold up, and the channels are very small so the tool won't "bite". Again, BE WARNED, you get what you pay for!Might work on wood, but won't stand up to Aluminum!

This worked ok to repair the threads on my car after my spark plug randomly decided to disembark from it. I had a couple of problems, firstly that the hex head on the tap in this kit takes a 21mm socket. That's a problem because my car has 6" long tubes through the valve cover and a 21mm socket will not fit in those tubes. I had to drill and tap the top of the tap and put a smaller bolt into it so that I could turn it once it was in the tube. Secondly, I reccomend putting some penetrating oil on the tap and taking it out and wiping off the aluminum shavings so they don't drop into the cylinder. I still wound up getting a little in there, I duck taped a length of tubing to my shop vac and stuck it down there to get some of it, hopefully anything that does go in there gets burned up and blown out of the exhaust. Finally, this is a one time use tool for aluminum heads only, the tap wore down quite a bit from just doing the one hole, it isn't hardened tool steel like a quality tap, it was really easy to drill into.Overall it's a decent fix for the price and worth trying before you replace the cylinder head.

I used this spark plug rethread kit on a 1964 Johnson 9.5 hp. Worked great. It's difficult to use if there are still some threads left in the spark plugs hole. But I used my small impact driver very carefully to chew up those treads. It seems the threader also hones the spark plugs holes before it starts treading. After inserting the threader about 1/3 with the impact driver, I did the rest with the Rachet and a socket. It worked perfect. I screwed the spark plugs in with the insert and used the Permatex Red thread lock on the insert threads only and after 24 hours I remove the spark plug and the insert is in there hard has a rock. This was a life saver. There are probably better ones out there that will be easier to use. But this one works to. You will need a lot of elbow grease and more than an hour to make it work. I recommend you remove the head after because no matter how much grease you put on the threader, there was a bunch of shavings in the cylinder when I removed my head.

Had to use tapered reamer to increase ID of stripped spark plug hole. Applied grease to reamer and cleaned several times to get to minimum diameter of tap. Then applied grease to tap and applied pressure to start tap -- pulled and cleaned and reapplied grease several times to achieve full thread depth. Cleaned new threads with brush and carb cleaner . Threaded insert on spark plug and applied RED Loctite to insert in new threads. Bota Boom Saw runs great.