--- product_id: 4077119 title: "Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811" price: "€ 39.23" currency: EUR in_stock: true reviews_count: 8 url: https://www.desertcart.hr/products/4077119-powerbuilt-14mm-back-tap-spark-plug-thread-repair-tool-straightening store_origin: HR region: Croatia --- # Saves time, no cylinder head removal 14mm precision threading Heat-treated 4118 steel durability Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811 **Price:** € 39.23 **Availability:** βœ… In Stock ## Summary > πŸ› οΈ Fix threads like a proβ€”because your engine deserves precision! ## Quick Answers - **What is this?** Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811 - **How much does it cost?** € 39.23 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/4077119-powerbuilt-14mm-back-tap-spark-plug-thread-repair-tool-straightening) ## Best For - Customers looking for quality international products ## Why This Product - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Time-Saving Efficiency:** Fix fouled threads without removing cylinder headsβ€”get back on the road faster. - β€’ **Precision Thread Repair:** Restores damaged spark plug threads with exact 14mm sizing for a flawless fit. - β€’ **ANSI Standard Excellence:** Meets or exceeds industry standards for reliable, professional-grade performance. - β€’ **Durable Heat-Treated Steel:** Built from premium 4118 steel to withstand high temperatures and tough repairs. - β€’ **Innovative Collapsible Design:** Easily insert through spark plug holes and expand inside for seamless thread restoration. ## Overview The Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool is a patented, collapsible device designed to restore damaged spark plug threads efficiently. Made from heat-treated 4118 steel and meeting ANSI standards, it repairs fouled threads without removing cylinder heads, saving time and preventing debris from entering the engine. Compact and durable, it’s an essential tool for motorcycle and automotive professionals seeking reliable thread repair. ## Description Buy Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811: Spark Plug Thread Repair Kits - desertcart.com βœ“ FREE DELIVERY possible on eligible purchases Review: This thing works! Great tool! - I was hesitant to order because there were some negative reviews, but since I'd already stripped the threads in my generator's engine and needed something, I went with this one. And it worked perfectly. If you want great results, take your time and play with the thing. Learn how it works. Snap it fully open, pop it closed again, slowly open it, all that stuff. Work with it. First of all, you want to make sure it works before you put it in your engine; if those expanding thread pieces are going to break off (like one review said), then you definitely want that to happen OUTSIDE your engine! But you want to play with it to see where the knob engages, where the expanding plunger stops spinning and starts gripping and spreading the threads outwards, etc. Second, do NOT put grease on the expanding plunger. You need friction there, you want it to grip the inside of the expanding thread "leaves" or whatever you want to call them. Grease up the threads plenty, you need that grease, but don't put grease where it can get on the inside of the leaves. Third, go slow, take your time, and as you're removing it and cutting new threads, if it suddenly gets a whole lot harder to turn, don't just force it through. Back it off a little. Reverse it and thread it back in maybe 1/4 turn, and then reverse it again and try removing it again; you will probably find that it works smoother the second time it traverses that same spot. What's happening is that as it's cutting new threads, chunks of metal are getting caught in the threads and binding up. You don't want to just force your way through that. By reversing and backing up, it lets those chunks of swarf get caught in the gaps between the four expanding "leaves", getting them out of the way of the threads, so it's much smoother to remove the second time you try to pass that same section. Fourth, go in a few passes. Don't expand it fully the first time you try it! Do like the instructions say, expand it some for the first run but not all the way. For my first run I tried to make the grooves between the leaves basically parallel, so the threads were pretty much even over the whole tool. Remember how many turns of the screw it takes to get it to that size. Then minimize it, grease it up, put it in, expand the leaves to that same size by backing the screw out to that same size, and extract it slowly from the socket. Then clean it up, get all the grease off it (especially between the leaves, where most of the swarf will be), and then split the difference between the expansion size you had (where the grooves are parallel) and the fully-expanded size. Find that middle ground, remember the number of turns of the knob necessary to get it to that size, and then minimize it, grease it, etc, same a the first pass. Then clean it off and grease it up and get ready for the final pass. Put it in the hole, hold the tool down with a wrench of the right size, and yank the rotating knob as far out as it will go so the leaves snap fully open, and then extract it once again, backing off when encountering higher resistance and then going forward again. Once you get it fully removed that third time, you should have perfectly functional threads again in the spark plug hole. I can tell you I did. For getting rid of the grease, I used the red can of Brakleen (chlorinated), and it washed the tool spotless. I hope to never use it again, but am very glad I have it. Really saved my neck (and my generator). Review: Works Well For Its Purpose - Works well for what it's made for. Understand this is not designed to re-tap super damaged threads. It's more for chasing and possibly repairing minor damage to sparkplug threads. Saving the original threads vs helicoils is always better because helicoils will fail and are never as good in terms of longevity. Also, to install helicoils, you have to thread in new bigger threads first and depending on the spacing of the sparkplug holes in the cylinder heads, that is not always possible. Have the piston at bottom dead center and insert tool. Once tool threads are all the way through, expand the tool and chase the sparkplug threads from the inside towards the outside of the sparkplug hole. This design prevents trash, debris, and other foreign objects from going inside the combustion chamber during the thread chasing and possibly causing problems/damage in the future. ## Features - SAVES THE DAY: The Back tap repairs the damaged thread as it is drawn up through the spark plug hole bringing any debris with it instead of falling into engine cylinder - PATENTED DESIGN: Collapsible design allows it to engage be placed through the spark plug hole and into the chamber; expands the tool's threaded area and threading into the clean threads drawn up through the plug hole repairing threads as it goes - TIME SAVER: Repairs fouled and damaged threads without removing cylinder heads; no need for tricky thread inserts - TOP QUALITY: Meets or exceeds ANSI standards - STRONG: Made of heat treated 4118 steel - Back-Tap 14 millimeter thread straightening tool for spark plug fouled threads - Collapsible design allows it to engage be placed through the spark plug hole and into the chamber - Expands the tool's threaded area and threading into the clean threads - Backtap repairs the damaged threads as it is drawn up through the spark plug hole ## Technical Specifications | Specification | Value | |---------------|-------| | Manufacturer | Powerbuilt | | Brand | Powerbuilt | | Model | Back-Tap Thread Repair To | | Item Weight | 5.6 ounces | | Product Dimensions | 4.79 x 9 x 1 inches | | Item model number | 640811 | | Is Discontinued By Manufacturer | No | | Manufacturer Part Number | 640811 | ## Images ![Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811 - Image 1](https://m.media-amazon.com/images/I/71PYfVRFEZL.jpg) ![Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811 - Image 2](https://m.media-amazon.com/images/I/71cJy1fnt9L.jpg) ![Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811 - Image 3](https://m.media-amazon.com/images/I/71g--zJuDZL.jpg) ![Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811 - Image 4](https://m.media-amazon.com/images/I/71lf0gC-W5L.jpg) ![Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811 - Image 5](https://m.media-amazon.com/images/I/71sHB1LAR0L.jpg) ## Available Options This product comes in different **Size** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ This thing works! Great tool! *by H***R on November 8, 2024* I was hesitant to order because there were some negative reviews, but since I'd already stripped the threads in my generator's engine and needed something, I went with this one. And it worked perfectly. If you want great results, take your time and play with the thing. Learn how it works. Snap it fully open, pop it closed again, slowly open it, all that stuff. Work with it. First of all, you want to make sure it works before you put it in your engine; if those expanding thread pieces are going to break off (like one review said), then you definitely want that to happen OUTSIDE your engine! But you want to play with it to see where the knob engages, where the expanding plunger stops spinning and starts gripping and spreading the threads outwards, etc. Second, do NOT put grease on the expanding plunger. You need friction there, you want it to grip the inside of the expanding thread "leaves" or whatever you want to call them. Grease up the threads plenty, you need that grease, but don't put grease where it can get on the inside of the leaves. Third, go slow, take your time, and as you're removing it and cutting new threads, if it suddenly gets a whole lot harder to turn, don't just force it through. Back it off a little. Reverse it and thread it back in maybe 1/4 turn, and then reverse it again and try removing it again; you will probably find that it works smoother the second time it traverses that same spot. What's happening is that as it's cutting new threads, chunks of metal are getting caught in the threads and binding up. You don't want to just force your way through that. By reversing and backing up, it lets those chunks of swarf get caught in the gaps between the four expanding "leaves", getting them out of the way of the threads, so it's much smoother to remove the second time you try to pass that same section. Fourth, go in a few passes. Don't expand it fully the first time you try it! Do like the instructions say, expand it some for the first run but not all the way. For my first run I tried to make the grooves between the leaves basically parallel, so the threads were pretty much even over the whole tool. Remember how many turns of the screw it takes to get it to that size. Then minimize it, grease it up, put it in, expand the leaves to that same size by backing the screw out to that same size, and extract it slowly from the socket. Then clean it up, get all the grease off it (especially between the leaves, where most of the swarf will be), and then split the difference between the expansion size you had (where the grooves are parallel) and the fully-expanded size. Find that middle ground, remember the number of turns of the knob necessary to get it to that size, and then minimize it, grease it, etc, same a the first pass. Then clean it off and grease it up and get ready for the final pass. Put it in the hole, hold the tool down with a wrench of the right size, and yank the rotating knob as far out as it will go so the leaves snap fully open, and then extract it once again, backing off when encountering higher resistance and then going forward again. Once you get it fully removed that third time, you should have perfectly functional threads again in the spark plug hole. I can tell you I did. For getting rid of the grease, I used the red can of Brakleen (chlorinated), and it washed the tool spotless. I hope to never use it again, but am very glad I have it. Really saved my neck (and my generator). ### ⭐⭐⭐⭐⭐ Works Well For Its Purpose *by H***O on November 30, 2025* Works well for what it's made for. Understand this is not designed to re-tap super damaged threads. It's more for chasing and possibly repairing minor damage to sparkplug threads. Saving the original threads vs helicoils is always better because helicoils will fail and are never as good in terms of longevity. Also, to install helicoils, you have to thread in new bigger threads first and depending on the spacing of the sparkplug holes in the cylinder heads, that is not always possible. Have the piston at bottom dead center and insert tool. Once tool threads are all the way through, expand the tool and chase the sparkplug threads from the inside towards the outside of the sparkplug hole. This design prevents trash, debris, and other foreign objects from going inside the combustion chamber during the thread chasing and possibly causing problems/damage in the future. ### ⭐⭐⭐⭐⭐ Worth every penny! *by T***E on March 23, 2025* This little tool is worth it's weight in gold! Had a JD mower come in with a cross threaded spark plug hole. This tool goes in with some grease to collect any shavings and lubricate. Make sure it's straight. You can feel when backing it our when it engages the threads by hand, and it will turn smoothly. Gradually tighten the screw and back it out by hand until it starts to get tight on the damaged threads. Use a wrench and gently bring it out. Takes about 3 times, each time adding a little more tightness. when you have the tool fully engaged, it wont tighten up anymore, you should still be able to back it out by hand until it gets to the damaged threads, then work it back and forth gently with a wrench. It'll take some time. Don't force! It is doing it's job. You will feel it getting easier each time you turn it back and forth. After you have it out, clean up and hand start your spark plug and you can tighten up to the gasket by hand, then snug properly with a socket. Done! This is a very good tool, works well. Note: Just don't get too much grease on the cone shaped wedge that expands the threads. It needs some friction in order to tighten up and expand the cutters. ## Frequently Bought Together - Powerbuilt 14mm Back Tap Thread Repair Tool - 640811 - ARES 70692 – M14 x 1.25 Limited Access Spark Plug Thread Chaser Tool – Low Profile Design for Confined Areas – 5/8-Inch Hex Head with 3/8-Inch Square Drive Design for Superior Versatility - Lisle 20020 Limited Access Spark Plug --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/4077119-powerbuilt-14mm-back-tap-spark-plug-thread-repair-tool-straightening](https://www.desertcart.hr/products/4077119-powerbuilt-14mm-back-tap-spark-plug-thread-repair-tool-straightening) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-05-19*