It Won't Start

I was doing some maintenance to my FJR. When I changed my sparkplugs the #2 spark plug will not start in the threads. Can I use a file and sharpen the threads on the sparkplug so it will engage the threads in the cylinder head? My impact wrench sure was helpful to get the other three sparkplugs installed.

ionbeam said:

I was doing some maintenance to my FJR. When I changed my sparkplugs the #2 spark plug will not start in the threads. Can I use a file and sharpen the threads on the sparkplug so it will engage the threads in the cylinder head? My impact wrench sure was helpful to get the other three sparkplugs installed.

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Use a belt sander, it will be a lot quicker than using a file and it will get you back on the road a lot faster.

Couple of whacks with a really big hammer will get that pesky plug seated......................nooo probelm.

Just thinking, six months from now some noob is going to 'do a search' and get this great advice about installing spark plugs.

So, he needs to know that when he starts filing threads off of the spark plugs he must do all four equally or he won't be able to get the throttle bodies synchronized, and get all of the threads completely off before welding.

Here's what I use..

Alan, check to make certain that you don't have a left-handed thread.

If you do, change hands when installing. It should work.

kaitsdad said:

Alan, check to make certain that you don't have a left-handed thread.

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I thought they only had left hand threads below the equator??? or is it just for left handed people???

It goes to eleven......

We are supposed to change them?

I like them the way that they are.

Geezer said:

Just thinking, six months from now some noob is going to 'do a search' and get this great advice about installing spark plugs.
So, he needs to know that when he starts filing threads off of the spark plugs he must do all four equally or he won't be able to get the throttle bodies synchronized, and get all of the threads completely off before welding.

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And don't forget to make sure that when you start filing the new plug threads, do so over the motor with the old plugs removed. The metal filings are good for the motor, but will seriously scratch the paint.

Sure you got the plug in the right hole? They're numbered: the plug with the 6 on it goes in cylinder 1, number 17 in cylinder 3, and so on.

Mine are numbered (left to right) 0001; 0010; 0011; 0100.

Before you go fil'in any plugs i mite want to try another one first. Sounds more like you might have something gumming up the threads on the cylinder head. I had an old ford witch was allways a bitch to get that last plug in. Took a while to get it lined up just rite.

Good luck.

Ionbeam,

If the threads in the head have been cross threaded, the threads are going to need cleaning up. If you use a conventional tap you run the risk of cutting a whole new set of threads outside of the originals. I had this same problem with a aluminum head small block Ford. I found a tool made by "KD" called a "Back-Tap" that handled the problem nicely. The way that it works is that the business end of the tool is contractable. In this state the tool is able to slip into the sparkplug hole without engaging the threads. Once the tool is past the threads and is in the combustion chamber a thumb screw is turned at the top of the tool to expand the diameter of the tap that is in the combustion chamber. Chances are that the threads at the bottom of the hole are clean and intact. At this point you simply thread the tool up and out of the hole. The tool chases the original threads up to the top and you are done. To keep metal bits from falling into the cylinder, coat the tap threads with Ivory hand soap (the bar of soap kind). The debris gets trapped in the soap. Hope this helps. Here's a link showing the tool. https://www2.shopping.com/xPO-Kd-Tools-3689...-Re-Thread-Tool

Bananas!

Good Gawd

IB, you haven't purchased your metric spark plug wrench yet; the length of the handle must be in mm

Bananas! said:

Ionbeam,Hope this helps. Here's a link showing the tool. https://www2.shopping.com/xPO-Kd-Tools-3689...-Re-Thread-Tool

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Thank you for your thoughtful and technically correct answer! Please keep up this kind of very helpful technical assistance!!!

I'm now embarrassed to confess that the original message, along with several others were launched on the same morning as part of a series of April 1st hoax messages :blush: Spare my spark plugs the air impact wrench!!!

Reminds me of the time I bought my first impact wrench, I had a 1971 450 Honda back then, gawd, I had parts everywhere!!! lol I learned a lot about the engine though...