Metal Lathes – Why everyone should have one!

Updates have been sparse lately, due to a TON of crank and cams coming in, lots of forks, and the general work I do on a daily basis, I have been swamped!  I’m not complaining.

The Big Mountain Run is coming up VERY soon, and its the only thing “biker” I like to really make an effort to do each year.  If you need more information, lets just put it this way – It’s a sweet ass motorcycle RIDE (I.E. Leave your trailer queens at the house folks) that ends up in TN with a hell of a party…  Good vendors, really great folks to ride with, and some amazing rides all through NC and TN…  Don’t miss it…

Being that I have taken my first bike on the BMR twice now, I decided I wanted to ride something else this year.  I’ve been beating down my father in law over all the random things he may or may not have repaired properly on the bike we built for him.  Well, he has decided that I can ride it for the BMR since he won’t be making it…  COOL!  Now I get to fix all the oddball shit that was done to it….  I’d love to show you some pics of it completed, but I’m gonna let it be seen first at the BMR…

Ok, so back to the the Lathe, and why you need one…   My FIL had the head “rebuilt” somewhere by somebody who didn’t have a clue what they were doing obviously…   The spark plugs threads were all buggered up, so they installed the infamous “Spark Plug Repair Kit” that you can find at all your favorite auto-repair houses….  This particular style NEVER works well in aluminum heads, but they installed it anyway….  So needless to say, I now had 2 really large holes in a the head of this bike where spark plugs wished they could reside along with some inserts that wouldn’t stay in…

I tried ALL the hardware places in town, but nothing was going to fix this short of me pulling the head, welding it up, drilling and retapping…  I had no time for that, so I made my own new inserts, something that can’t be found online or on the shelf somewhere…  After a few careful measurements with my eyecrometers, I whittled these down from some 7075 Al.

M14x1.25 threads ID, and 3/4-16 Threads on the OD.


I took my time drilling out the head, making sure the valves were closed so as not to knick them with the drill (it was a very close fit).  If you are really careful, and coat your drill in some super tacky grease, you won’t get any chips inside the cylinder.

All drilled out and ready to be tapped.  I stepped up the hole in 1/16″ increments until I was at 11/16″.  I coated the tap in grease just like I did the drill bits, and miraculously didn’t get any chips inside the cylinders.

I used a liberal coating of RED Lock-Tite and installed the new inserts using an old spark plug.  I let it sit for a few hours, hit it with some heat and then removed the plugs. I installed new plugs, and took it for a test ride!  It was nice making it more than 20 feet without blowing out a plug.

So I got a chance to ride about 75 miles today, some highway, some on the back roads and really beating on the engine…  I think my BMR ride is just about ready…  Now to tidy up some wiring, do a little base tuning, and tie on my Bedroll…

It is the ability to make time saving things like this, that really make having a lathe and learning how to use it so worthwhile…  Otherwise, I’d have been riding my ugly beater KZ650 on the BMR…  Instead, now I can let my friend Tom ride it and have a buddy to go with me…

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