Out of the Closet

I have been working a lot of overtime lately so I get home pretty late at night, too late to turn the air compressor on to finish stripping the paint and rust off of the swingarm. So, I've been working on the small parts that I could do by hand. I finished cleaning and sanding almost all of the small bits that will get the brushed finish with the exception of the motor mounts. They have a lot of rust on them and are going to require some grinding and sanding with the air tools along with the swingarm. After I got the finish how I wanted it, I cleaned the parts with denatured alcohol and then sprayed them with the high heat clear enamel I've been using. Since I'm not home when it is light out, I had to paint the parts under one of the flood lights out in the yard. On the first set of parts I painted, I wasn't in the best spot and couldn't see very well. I ended up putting too much paint on the parts and got a bunch of runs. So now I will have to sand those before I do the second coat. The other half of the parts came out very well, e. Except, I ran out of paint before I got the second coat on all of them. The picture shows some of them hanging in my closet drying. I didn't want to leave them out in the garage overnight because it is starting to get cold. Once they are all fully painted, I will cure them by hanging them in front of the space heater like I did the other parts.

[Insert Clever Title]

Time to update this slow rebuild process. I recently changed jobs so I haven't made great progress in rebuilding Nixon, but I am slowly chipping away at things. It is just a matter of taking something completely apart, remove 35 years worth of dirt and rust, cleaning and then painting it. I've got the Carbs done and they look great. I also finished the guages, the toolbox and the exhaust collars. I'm currently working on the swingarm. I replaced the old cruddy bushings with some nice new bronze bushings. The swingarm is going to have the brushed metal finish so I am cleaning all the paint and rust off of it so I can sand it.


I also got the cylinder head back from the mechanic who installed the new valve guide and refurbished the valve seats. They should work much better now. Found out I need to replace one of the cam followers so now I am on the hunt for one of those. Now all I need is a gasket set and the head is ready to go back together.

Baking Brownies

I got the rest of the head disassembled and all of the parts bagged and tagged. I bought a used cam chain roller and a new valve off of ebay to replace the broken/bent ones. I spent last weekend cleaning off all of the mating surfaces that will be getting new gaskets. There was some old gasket glue on them and I wanted them to be clean, smooth and shiny. I also cleaned off all of the buildup in the combustion chambers and in the valve ports. When I cleaned out the exhaust ports, 35 years worth of carbon dust came billowing out. Good thing I did that outside. I also noticed that the exhaust valve seats were pretty cruddy. I think they were not seating right which might have led to some of my low compression and poor engine performance. Although it is hard to see in the picture below, there was a whole lot of crud baked on there.

I also painted some of the other parts I had previously cleaned and given the brushed metal finish to. The brushed metal parts are painted with a clear enamel and the satin black parts are painted with a black enamel. The enamel should be heat cured for full hardness, but I didn't want to stick my parts in my oven. So, I hung them in front of a small space heater I had for about 20 minutes each. The second picture is the tachometer being "baked". They got too hot to touch and hopefully that is enough. I still have some more parts to do as well as the carburetors.

No Dissassemble Johnny5!

Made some more progress on the engine last weekend. I removed the exhaust cam, torsion bar springs and valves. The torsion bar springs which are the hallmark of this engine were a lot easier to get off than I had expected; a lot easier than I hear standard coil springs are to remove. Lets hope they are just as easy to reinstall. I've already made the special tool required to install them out of a cheap socket. The left exhaust valve is the one I bent. You can see it kind of pointing off to the side in the second picture. Since the valve guides that the valves slide in are reamed to exactly fit the stem of each valve, the bent valve was obviously not going to just slide out. I thought about cutting it just above the valve guide with my trusty dremel tool, but decided to try to bend it back as straight as I could first. I got my big set of channel locks and started bending. It took about 20 minutes of bending and rotating and bending again, but it eventually just slide out. I know the valve is scrap and I am going to replace the guide as well just to be safe. Next I will take the intake cam, springs and valves out. The head and valves will get cleaned and the valve seats redone.

I also took the cylinders and the pistons and piston rings off. As I said, the bike had low compression and was blowing smoke before I bent the valve so the cylinders and rings will get redone as well. I'm going to go ahead and polish the pistons and head as well while I have the engine apart. Now I just need to find a good machine shop.

Pop The Top

Engine disassembly has begun. To remove the top end which houses the overhead cams and the valves, you have to remove the cam chain that feeds through it. I had to buy a chain breaking tool since the master link on the cam chain is riveted. Once I received that, and figured out how to use it, I was able to get the cam chain off. The directions in the motorcycle manual say to make sure to tie off the cam chain so that it does not fall down into the engine when you break it. I did this with electrical wire, which I quickly discovered was not strong enough. Luckily, I had not pushed the chain link pin out all the way and the chain got caught on something before it fell all the way down. I got some wire hangers and bent those up to hold the chain. I took the head off and took a peek inside. The pistons and cylinders didn't look too bad. The valves looked pretty cruddy though. I could see the valve that I bent would not close all the way. Definitely going to going to need to be replaced. I also notice that the pin for one of the cam chain rollers was loose. I was actually able to pull it out and I couldn't figure out how it was supposed to stay in. After looking it up online, I realized that one end was supposed to be deformed like a rivet. Apparently that deformed part had broken off of mine. How did this thing not explode when I took it up to redline?

Breaking the cam chain

The broken cam chain roller pin