Of Minds and Motorcycles

Day 2 – Engine

"Careers, like rockets, don't always take off on time. The trick is to always keep the engine running." - Gary Sinise

I was so busy yesterday that I didn't get to write a post the day after I made a challenge to myself to write a post every day for the next month. Luckily the first post was written after midnight and technically was posted on February 3rd, so I haven't missed a day. So don't worry everyone I haven't disappointed myself! I know you were very worried!

"You're doing what?" - Someone who doesn't read my blog.

More importantly I almost missed posting an article because I was deep into the engine of El Citron and didn't sleep until 4 in the morning.

Building a better lemon

Just before the new year my buddy Roger, who has been building vintage dirt bikes for a while now and is becoming somewhat of a 2-stroke engine specialist, offered to help me rebuild the engine in the S3. I knew something was wrong with the bike, but wasn't sure whether it was mainly a tuning issue with the carburetors or actual problems inside the engine. I've also never taken an engine apart before, and it is quite the intimidating task. So without Roger suggesting it I probably would have left the engine as is while reworking everything else. From what we ended up finding inside, it looks like I made the right decision.

First off, we set the engine on a table. This particular table happens to be a damned good welding table that was about to get doused in various oils. Because it's a 2-stroke, I was actually able to lift the engine into my car and drive it there without any help - a welcome break from working on the XS1100 which is still sitting in the garage while I overthink taking the engine out.

s3 engine

Next we took the heads off, followed by the cylinders. This was the moment of truth to see whether I was dealing with a simple piston change or a full engine overhaul.


Sure enough the cylinder walls were in pretty bad shape. I wouldn't necessarily have been able to tell with my limited engine building experience, but Roger assured me that the shiny burnt line appearance of the cylinders was a bad thing; not to mention the broken piston rings and the gouge marks in the top of the middle piston. Something broke off and was banging around in there, and the side cylinders were just plain worn out. Well the good news is I've now discovered why El Citron was such a citron.


cylinder walls

Now for the fun part. Since the genius who had worked on the bike in a previous life had decided to weld the kickstarter to the shaft, we had to first grind off the weld while trying to keep the parts intact. I'm trying to improve on my usual break-it-and-buy-a-new-one policy, especially with obscure vintage engine parts. Engines apparently have a lot of parts, apparently.


Next we took off the points, timing, and stator thingy. I think this is the part where I also needed a special flywheel puller tool, but I can't remember for sure. I'm not calling all of these things by their proper names, but I'm trying to write a post here and am just going to have to leave it at that. You know, all the timing stuff, and one of them's a spinning magnet thing which makes me think it's a generator of sorts. Very technical; take notes guys, there will be an exam later. The correct answer is definitely: "stator thingy".

ignition timing

stator thingy - it's magnetic folks

Next we took off the sprocket by blocking one of the pistons with a wrench to stop it from spinning, and pulling off the sprocket nut while trying not to hit Roger in the face. Followed by heating up the cases and trying not to drop a propane torch into me by accident. Actually that came later.

The oil pump was easy as I'd done it before when it was leaking oil all over Toronto's roads and driveways. I have to decide whether to get rid of the oil pump entirely and run premix, or just keep the pump for ease of streetability. We shall see.

oil pump

On the other side was the clutch, and the drive gear things that drive the transmission. These came off fairly easily and were put aside. Remember, write it down: drive gear things.


clutch removed

Finally after removing more springs and plates, and all the nuts on the bottom of the case, we were ready to split the cases. This required gentle whacks of the hammer combined with heat and slipping an exacto blade through the seams. After a few minutes of struggling to move the cases, we found the last hidden nuts and were able to split the cases:

engine cases

And that's about it! The rest is boring stuff, like how I wrapped the transmission in a cloth and set it aside as it won't be touched until reassembly. The crankshaft had some marks on it as well from what looks like a sharp object rattling around in there. Piston ring chunk perhaps? Or maybe that's from when my air filter cap fell off and something from the street got into the engine. Whoops! It needed to be rebuilt anyway. I also had stripped the drain bolt but found out that I wasn't the first offender. There was hardly any thread left. Luckily that part of the casing is big enough to support a larger hole. I'll just put a bigger drain plug in, the least of my concerns.

crank and transmission

Crankshaft and transmission



The cases will be sent for soda blasting, or cleaning, and the cylinders will be bored with all new pistons and rings from Wiseco. Other than that I'll have to learn as I go along. Hopefully this engine gets built sometime before next winter!

I must now take a nap as I'm running on very little sleep. I even woke up early and removed snow from my parents driveway with a snowblower. What a good son I am. The snowblower was kind of fun though, I have to say.

Snow removal


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