Project Shinjimei- 73 TX500

Pete12

Member
two-smoker said:
I can't find either a 520 front sprocket for the Honda motor, or a 525 sprocket to fit the YZ250 rear hub
Has the Rebel got a fine or coarse countershaft spline (13 or 6)? You might find a sprocket from an XL500/XR600 that will do the job. Most sprocket sellers on Ebay include a dimensional drawing that makes it really easy to mix and match.
 

my-79-750-k

Therapy is expensive. Riding is cheap. You decide.
Maybe buy a blank sprocket from somewhere like McMaster-Carr and have it broached at a shop to fit the splines of the engine?
 

Pete12

Member
two-smoker said:
I have no clue. I haven't taken it off the bike.
I can understand your trepidation, it's a major job, not to be undertaken without considerable forethought and planning, not to mention the special tools involved
 

two-smoker

I reject your reality, and substitute my own!
I can understand your trepidation, it's a major job, not to be undertaken without considerable forethought and planning, not to mention the special tools involved

Oh, you're funny. Lol.
Seriously, though, I haven't had the time or desire to freeze my ass off out in the garage. When it's above 20 degrees Fahrenheit for more than a day, I'll be moving fast on this.

Sent from my LG-LS777 using DO THE TON mobile app
 

two-smoker

I reject your reality, and substitute my own!
The sprocket from a 79 - 81 Honda XL500S has the same spline as the CMX450C. It is a 520.
Thank you! That's exactly the information I needed.

Sent from my LG-LS777 using DO THE TON mobile app
 

Pete12

Member
two-smoker said:
No, 520 is a narrower 530. 525 had different distance between the rollers. Tooth pitch, if you will.

Sent from my LG-LS777 using DO THE TON mobile app
520 is 5/8" pitch x 1/4" width, 525 is 5/8"x5/16" and 530 is 5/8"x3/8", all the same pitch.

Love the new carbs, are they the Chinese copies and, if so, what's the quality like?
 

two-smoker

I reject your reality, and substitute my own!
Pete12 said:
520 is 5/8" pitch x 1/4" width, 525 is 5/8"x5/16" and 530 is 5/8"x3/8", all the same pitch.

Love the new carbs, are they the Chinese copies and, if so, what's the quality like?
I stand corrected... I knew that you could use 530 chain on 520 sprocket in a pinch... Didn't know 525 has the same pitch. Might've saved myself some aggravation if I hadn't already bought a new sprocket.
They actually look every bit as good as real Keihins, to be honest... Maybe the finish is a little more dull, but they did a really good job machining the bores and slides. I'm surprised. And at the price, I don't care if they fail. I can still afford Mikunis if they do.

Sent from my LG-LS777 using DO THE TON mobile app
 

Pete12

Member
Good stuff. The only thing I would do with carbies is put genuine Keihin jets in, particularly the mains, as the Chinese jet sizing sometimes leaves a little to be desired. I've seen a larger jet number with a smaller hole which obviously causes all sorts of problems.
 

two-smoker

I reject your reality, and substitute my own!
Pete12 said:
Good stuff. The only thing I would do with carbies is put genuine Keihin jets in, particularly the mains, as the Chinese jet sizing sometimes leaves a little to be desired. I've seen a larger jet number with a smaller hole which obviously causes all sorts of problems.
Indeed. I know I'm gonna have to change the jets anyway. Might as well get the good stuff.
 

two-smoker

I reject your reality, and substitute my own!
http://imgur.com/gallery/VZDsZ65
I made my first attempt at fitting the Rebel 450 engine into the Yamaha frame. After I cut off all the original Yamaha mounts, it'll go right in. Then I need to fab up new mounts.

Sent from my LG-LS777 using DO THE TON mobile app
 

two-smoker

I reject your reality, and substitute my own!
I decided to replace the lower frame section of the Yamaha with the part of the Honda frame that holds the motor mounts. I figure it's easier than trying to make room in the Yamaha frame as it sits, plus it allows me a little room to place the motor where I want it.
Anyone need some Rebel parts?

Sent from my LG-LS777 using DO THE TON mobile app
 

Attachments

two-smoker

I reject your reality, and substitute my own!
datadavid said:
Props for building anything with yamahas worst, most fragile and unreliable bike ever
You know, it's not as bad as people think. Especially the later models. By '78, they really had it nailed. I mean, think about it. You had a DOHC, 4 valve-per cylinder design with a balance shaft, and by then they had everything set up to be either self-adjusting, or extremely easy to do. And they had higher horsepower then any other 500 twin for years. Even the Ninja 500 didn't make as much power. Yeah, they had quirks, but when did any design not start out with some issues? Yamaha fixed everything, then gave up.

Sent from my LG-LS777 using DO THE TON mobile app
 

datadavid

New Member
Cool, they have a horrible reputation here, tx750's being the worst. Apparently all balancer and oil froth issues can be solved though.
 
Top Bottom