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