Big TX500 project, any help appreciated!

[Made2care]

I always have a vision with a project. I wanted a bike with dual exhausts-check, small low lying tank-check, not too big of an engine-check and of course… that 70’s style -check.
Sounds weird and I’m not crazy but the bike kept luring me back to my shop each time I walked by, like “ please don’t walk away”.
I did manage to free the cylinders to where it turns about 1/4 of a turn and no more. I just wonder what’s binding it up? Maybe the counterbalancing chain? Who knows.
I’m going back and forth in my mind.
I did find an engine 3 hrs away but the owner says it binds up as well … and he wants $500 for it which I’m not paying.
She will sit in my shop this week as I’m pretty busy. I’ll decide this weekend what to do.
Thanks to everyone for their suggests, considerations and concerns. Will keep you posted!

 

[gggGary]

In a situation like that I'll run a for sale ad that's also a looking for parts ad. Often as not the guys looking at some odd old bike already have a barn full of em. Ask me how I know.

 

[Made2care]

The more I’m researching this bike, the more discouraged I become.
I wish I could just transplant a 76 engine.
What’s the point of trying to save a 74 engine that’s prone to fail… makes no sense.

 

[Wingedwheel]

https://www.facebook.com/marketplac...wse_serp:929e3850-85da-493f-822a-27eeafe8dfed
https://www.facebook.com/marketplac...wse_serp:929e3850-85da-493f-822a-27eeafe8dfed
They are out there.

 

[arcticXS]

Well, at least the TX500 and later XS500 engine has potential for some serious power:
https://www.xs650.com/threads/interesting-motorcycles-not-xs650.61760/post-806633

 

[Wingedwheel]

https://www.facebook.com/marketplac...4416505374271042122","ftmd_400706":"111112l"}
I would offer less but there’s a set for you.

 

[Made2care]

I’m going to shop around for a 76 engine. Hopefully I can get one shipped to me. I’m assuming the 76 will transplant into my 74 frame with no issues?

 

[Wingedwheel]

https://archive.org/details/yamaha-tx-500-500-a-service-manual
This will help

 

[Jim]

https://archive.org/details/yamaha-tx-500-500-a-service-manual
This will help

Just took a look at that manual.... wow! It's a lot more thorough than our 650 manual.

"The TX500 employs a 180° crankshaft and over square pistons."

That's what Honda used in their early small twins. So if you're of the opinion that a 305 Superhawk winding the gears out to redline is one of the sweetest sounding twins ever made, then I'm guessin' you'd love the sound of this engine. I've never actually heard (or seen for that matter) one in real life.

Kinda makes me want one now.

 

[Steve C]

Omni-Phase Balancer! If this chain is disconnected it could cause the crank shaft bind you're having?

 

[jetmechmarty]

So if you're of the opinion that a 305 Superhawk winding the gears out to redline is one of the sweetest sounding twins ever made, then I'm guessin' you'd love the sound of this engine. I've never actually heard (or seen for that matter) one in real life.

 

[mick71b]

So if you're of the opinion that a 305 Superhawk winding the gears out to redline is one of the sweetest sounding twins ever made, then I'm guessin' you'd love the sound of this engine. I've never actually heard (or seen for that matter) one in real life.

Kinda makes me want one now.

Very true! My '76 sounds like my 650 until the rpm's come up. It likes to rev.

 

[Jim]

+Here's one winding out through the gears. Starts at about 8min. in. Yeah, sounds just like an old Superhawk.

 

[Wingedwheel]

Check the supplements in the back for additional info. That’s where I found the info on the Cush wheel I used on my Bobber.

 

[5twins]

Yes, a very nice rear wheel for 650 use, pretty easy to adapt. A "before" and "after" look at the one I set up for my 650 .....

It's a pretty easy wheel to adapt because it uses the same axle diameter and bearings, also the same sprocket mount. All one needs to do is fab up a few spacers and they can be made from an old sprocket.

 

[Made2care]

+Here's one winding out through the gears. Starts at about 8min. in. Yeah, sounds just like an old Superhawk.

Wow!!!! Amazing!

 

[Adamc]

Very true! My '76 sounds like my 650 until the rpm's come up. It likes to rev.

View attachment 252053

Nice bit of kit @mick71b

 

[5twins]

I don't know where you're located but like I said, there's 3 of these sitting in my dealer's boneyard, engines pretty much intact. I'm sure he'd let one go cheap (like $50 or less).

 

[Made2care]

I don't know where you're located but like I said, there's 3 of these sitting in my dealer's boneyard, engines pretty much intact. I'm sure he'd let one go cheap (like $50 or less).

City, state?

 

[Made2care]

More pics!