1975 XS500

[bbailey72]

I was gifted a 1975 XS500 by a friend who just wanted it out of her garage, and I figured this was the perfect chance to start learning about motorcycle engines. After binge-watching hours of YouTube tutorials, the first thing I did was pour some Marvel Mystery Oil into the cylinders.

The first issue I ran into was that the rear wheel wouldn’t spin. I suspected the rear brake might be the culprit, so I loosened the rear tire enough to remove the chain—the tire spun freely, so that wasn't the issue. I’m about 93.2% sure the bike is in neutral. I also removed the clutch cable and sprayed some lubricant to help free it up, but it's still a tough squeeze.

Then I decided to put a little pressure on the kick starter just to see what would happen. Turns out, it sprays Mystery Oil all over the garage. So now I’m looking for advice on what the problem could be. I’m very new to this, so please explain things like I’m 12. Thanks!

 

[jetmechmarty]

Wow! That’s very cool!

Here’s what I would do:
Take the junk off of it. Fairing, bags & rack.
Acquire a service manual, preferably factory.
Prepare to service the entire motorcycle from nose to tail. Forks, headstock, everything!
Often, whatever is broken will turn up in the process. Make a list as you go.

You indicate that the kicker rotates the engine. True? Rear wheel would not rotate with the chain on? It’s not in neutral.

Don’t get ahead of yourself. You need to figure out what’s going on. It may be best to put the wheel and chain back on for the time being.

Hopefully, the factory service manual is available online somewhere.

FWIW, that bike is known to crack the cylinder head. A late model XS500 (made after Yamaha corrected the issue) cylinder head swaps directly is my understanding.

 

[grouchie77]

I’m about 93.2% sure the bike is in neutral.

This is great. You're gonna get along just fine around here.

Where at in Illinois are you? I'm in Joliet.

You said it sprays "all over the garage". Can you source where the potential leak is coming from?

Marty has it right though, get yourself a manual. That's probably the most important tool you'll own.

 

[Jim]

FWIW, that bike is known to crack the cylinder head. A late model XS500 (made after Yamaha corrected the issue) cylinder head swaps directly is my understanding.

If I'm not mistaken, his '75 already came with the upgraded head from the factory.

 

[Grimly]

Take the junk off of it. Fairing, bags & rack.

Heathen!

 

[grouchie77]

There's nothing wrong with being Heathen...

 

[jetmechmarty]

Heathen!

It needs to be out of the way. TBD if it gets reinstalled.

 

[bbailey72]

It needs to be out of the way. TBD if it gets reinstalled.

I do have bags and rack off of it. The fairing will be off at some point.

 

[bbailey72]

Wow! That’s very cool!

Here’s what I would do:
Take the junk off of it. Fairing, bags & rack.
Acquire a service manual, preferably factory.
Prepare to service the entire motorcycle from nose to tail. Forks, headstock, everything!
Often, whatever is broken will turn up in the process. Make a list as you go.

You indicate that the kicker rotates the engine. True? Rear wheel would not rotate with the chain on? It’s not in neutral.

Don’t get ahead of yourself. You need to figure out what’s going on. It may be best to put the wheel and chain back on for the time being.

Hopefully, the factory service manual is available online somewhere.

FWIW, that bike is known to crack the cylinder head. A late model XS500 (made after Yamaha corrected the issue) cylinder head swaps directly is my understanding.

I do have bags and rack off.
I have a manual, just not sure if it's the service manual. I posted a pic.
The engine hasn't really rotated, it just moved enough to spit the mystery oil out of one of the cylinder. It hasn't moved since. Scared the hell out of me.
Correct, the rear wheel would not rotate with chain on. There wasn't much oil, if any, in the bike, so i put about a quart and a half in it and also some mystery oil thinking that might help loosen something up.
I'm pretty sure this bike was running when it was parked if that would make any difference.

 

[jetmechmarty]

I do have bags and rack off of it. The fairing will be off at some point.

Repack or replace steering head bearings is one of the tasks you have to do. It will be much easier with the fairing off.

 

[jetmechmarty]

Owner manual is great, keep it. It’s no good for what you have to do, though it probably has the service schedule.

 

[bbailey72]

And thanks all for the quick replies, this is gonna be fun

 

[Jim]

I've found you a shop manual. Unfortunately it's too large for this forum. Give me your email and I'll send it too you.

 

[Jim]

Disregard my previous. Here's a link to the download. I downloaded it.... it's safe.

https://www.dotheton.com/downloads/Yamaha_TX500_500A_Service_Manual.pdf

 

[bbailey72]

Disregard my previous. Here's a link to the download. I downloaded it.... it's safe.

https://www.dotheton.com/downloads/Yamaha_TX500_500A_Service_Manual.pdf

perfect, thanks

 

[Jim]

I’m very new to this, so please explain things like I’m 12. Thanks!

Give us some more background info... Like do you own tools? Metric tools?
What type of mechanical experience do you have?

What I'm gettin' at is can you realistically see this project through? It's a 50 yr old bike. Even if it was a runner, it's still gonna need a ton of work. It's gonna take a commitment to see it through on your part.

We're a helpful bunch here, but most of us have little to no experience with the TX500. That means we'll be learning as we help you sort through what's needed to make it a runner. And trust me, the brain trust here is good enough to solve any problem that bike throws at us.

I'm willing to spend the time (as are others) helping you sort it all out... "if" you're committed to seeing it through. If you're not, we'll just be wasting our time helping. See where I'm going with this?

Do some soul searching and ask yourself if this is really the bike/project you really want to sink your teeth into?

 

[bbailey72]

Give us some more background info... Like do you own tools? Metric tools?
What type of mechanical experience do you have?

What I'm gettin' at is can you realistically see this project through? It's a 50 yr old bike. Even if it was a runner, it's still gonna need a ton of work. It's gonna take a commitment to see it through on your part.

We're a helpful bunch here, but most of us have little to no experience with the TX500. That means we'll be learning as we help you sort through what's needed to make it a runner. And trust me, the brain trust here is good enough to solve any problem that bike throws at us.

I'm willing to spend the time (as are others) helping you sort it all out... "if" you're committed to seeing it through. If you're not, we'll just be wasting our time helping. See where I'm going with this?

Do some soul searching and ask yourself if this is really the bike/project you really want to sink your teeth into?

I have a lot of tools, including metric. If I need something, I’m not far away from harbor freight. Part of the enjoyment is buying new tools.
Mechanical experience on a scale from 1-10, I’d be a 3.
My goal is to see this through, I’d love for this to be a hobby of getting old bikes running.

 

[bbailey72]

This is great. You're gonna get along just fine around here.

Where at in Illinois are you? I'm in Joliet.

You said it sprays "all over the garage". Can you source where the potential leak is coming from?

Marty has it right though, get yourself a manual. That's probably the most important tool you'll own.

I live in a small town a few miles north of Springfield.
The mystery oil shot/sprayed out of one of the cylinders

 

[grouchie77]

Do you have a helping extra set of hands? If you pour more of that oil stuff in there, could a buddy/friend/wife/girlfriend kick the kickstarter and you see where it's shooting from?

As an alternative, clean the motor real well with a buncha rags, take some before photos, kick it, take some after photos, and post em here. We love photos of bikes almost as much as of ladies.

 

[grouchie77]

Also, how did you pour it into the cylinders to begin with? I'm guessing a funnel thru the spark plug hole.

....did you put the plugs back in???