Once a broken bike is home, the job changes. It isn't about deciding whether to buy it anymore — it's about finding out what's wrong without adding anything new to the list.
Home in the garage
While checking the XR500 over in my garage after getting it home, I wasn't sure what was wrong, but I was assuming it was something in the top end. I was cautious moving it around. I didn't want to damage anything at all by turning the engine over, as I thought maybe there was an issue with the rings. What pointed me to the top end was the way the seller told me not to kick it over.
That caution is the whole idea of this post. When something inside an engine is already broken, turning it over can make it worse — whatever is loose or damaged gets moved around against the parts that are still good. Until I knew what was wrong, the safest thing the engine could do was sit still.
Being in my garage, it's a lot easier to catch all the details. Maybe that's because the environment is my own, and I don't have to take in everything else in addition to the motorcycle. At a seller's place there's the seller, the conversation, the price, and the drive home to think about. In my own garage there's just the bike.
The JB Weld
Almost right away I noticed JB Weld on the bottom end, and I was upset with myself that I didn't notice it while buying the bike. Not that I'd have passed on the bike, and I don't know that I could have talked the guy down more — but just the fact that I missed it was upsetting.
The JB Weld wasn't there for style. I'm sure it was covering up a hole. And I knew that to split the cases, I'd have to use a cutting wheel to dig the JB Weld out — and that I'd likely need new cases.
Getting the engine to the bench
Avoiding making the damage worse was definitely my focus. To rebuild the engine, I'd need to split the case's top and bottom halves, as well as remove the clutch cover. To do that properly, I'd need the engine on my workbench.
That means removing hardware and parts that may never have been off in almost 50 years. Fasteners that old have had decades to rust and seize in place, and each one is a chance to strip a head or snap a bolt if it's rushed.
This time, nothing fought back. There was no damaged hardware and no fights getting the engine onto the bench.
The right tool, every time
I always find the right tool to remove anything. With any part — especially old, used parts — the wrong tool will damage perfectly good parts.
The wrong tool will damage perfectly good parts.
As a new, aspiring mechanic, it's a near certainty that you don't have all the tools needed. Obscure tools like a flywheel puller or a clutch holder are unknown to anyone who has never disassembled an engine. A flywheel puller does exactly what it says — the flywheel won't come off by hand. A clutch holder keeps the clutch from spinning while its nut comes off. Without them, the temptation is to improvise, and improvising on a 50-year-old engine is how good parts get broken.
But even not having the right sockets or wrenches — metric or imperial sizes — or even the right kind of screwdriver, JIS or Phillips, can damage perfectly good parts. A wrench that's almost the right size rounds off a bolt head. A Phillips screwdriver in a JIS screw looks like it fits, and then it slips out and chews up the head.
- The right sockets and wrenches — metric or imperial, the correct size.
- The right screwdrivers — JIS or Phillips.
- A flywheel puller.
- A clutch holder.
- A rotary tool with a cutting disc, for the JB Weld.
After collecting all the right tools — or learning how to fabricate one, which is a more advanced tactic — I'm able to disassemble a motorcycle relatively quickly, and without breaking anything.
Cutting out the JB Weld
Once the engine was on the bench came the task of grinding off the JB Weld. For this task I actually got a new tool: a rotary tool with a cutting disc.
Even with a large toolchest of motorcycle-specific tools, I'm always adding new tools to do more and more specific tasks. Or, in the case of the rotary tool, to improve on a tool with a more powerful electric one, so I didn't have to cut out the hardware now buried under JB Weld by hand.
With a little patience and my new electric grinding tool, I was able to split the cases without damaging them further.
Under the JB Weld was what I'd suspected: a hole. There was a very large hole in the clutch cover — big enough that the oil leaked out quickly.
Damaged is better than destroyed
I knew chances were the cases were already junk. But damaged parts are better than parts so badly damaged they can't be repaired.
A worn part that's cared for beats a part destroyed carelessly in removal.
That's the deeper point of all the caution. Even damaged or worn parts are better options, if they're cared for, than a part that's destroyed carelessly on its way off the bike. A worn part can still be measured, repaired, or used to find the right replacement. A part broken in removal is just one more thing to buy.