My 73 Yamaha TX750 Rebuild....

[SOS]

I picked up a very ratty 1973 TX750 out of the junk yard last fall. Someone had given it a funky rat / cafe treatment sometime in the past and it had a cool rusty look to it so I stuck it in the window at the shop. Things slowed down over the last couple days so I put in on the lift to see what would happen. Cleaned the carbs, checked the timing and threw on an aux tank. Wiring was hacked so I put 12v straight to the coil. Scared the cramp out of me when it actually fired up and ran.

I think it has the extended oil sump and I'll check for the hole at the points case (no evidence of oil though). I'm hoping to find the adjustable chain for the balancer. I really didn't expect it to run so now I'll look a bit more carefully. It should be a fun shop bike

[ctune80]

I've always liked the TX750, and from what I hear the bike was great if you didn't live at the
top of the rev range and kept up on routine maintenance. The balancer adjuster was
also needed. A shame a little more development wasn't done before original release.

I went to talk to the Yamaha Dealer in my old hometown recently, (I moved many years ago)
We talked about the old days, reminisced about DT1's and XS's, when the talk
turned to TX750's his facial expression said it all. That bike cost Yamaha and the
local dealers a lot of money. I love the TX for it's uniqueness, but his experience
was a lot different than mine!

[concours]

Originally Posted by ctune80

I've always liked the TX750, and from what I hear the bike was great if you didn't live at the
top of the rev range and kept up on routine maintenance. The balancer adjuster was
also needed. A shame a little more development wasn't done before original release.

I went to talk to the Yamaha Dealer in my old hometown recently, (I moved many years ago)
We talked about the old days, reminisced about DT1's and XS's, when the talk
turned to TX750's his facial expression said it all. That bike cost Yamaha and the
local dealers a lot of money. I love the TX for it's uniqueness, but his experience
was a lot different than mine!

Yup, no doubt the unhappy customers made headaches for the dealers, and the warranty work isn't lucrative either. This thing is faster, MUCH smoother, better brakes, better lighting, handles as well as my '77 Bonney.

[concours]

Originally Posted by SOS

I picked up a very ratty 1973 TX750 out of the junk yard last fall. Someone had given it a funky rat / cafe treatment sometime in the past and it had a cool rusty look to it so I stuck it in the window at the shop. Things slowed down over the last couple days so I put in on the lift to see what would happen. Cleaned the carbs, checked the timing and threw on an aux tank. Wiring was hacked so I put 12v straight to the coil. Scared the cramp out of me when it actually fired up and ran.

I think it has the extended oil sump and I'll check for the hole at the points case (no evidence of oil though). I'm hoping to find the adjustable chain for the balancer. I really didn't expect it to run so now I'll look a bit more carefully. It should be a fun shop bike

I see the balancer chain retrofits on ebay once in a while. Be very carefull, there is a bunch of small parts (spacers, etc.) you really NEED to do this retrofit. The ancient parts retrofit list calls them all out.

http://www.tobyfolwick.com/tx750/textual/pbadj_1.php

http://www.tobyfolwick.com/tx750/bulletin.php

[lsettle]

Nice work on the TX.

Question for you. When you check the oil level, is the dip stick inserted all the way down or should it be sitting on the tube?


Thanks,


Lawrence

[concours]

Originally Posted by lsettle

Nice work on the TX.

Question for you. When you check the oil level, is the dip stick inserted all the way down or should it be sitting on the tube?


Thanks,


Lawrence

Thanks! Seated all the way down is the correct method.

[concours]

The spin on oil filter I fabbed up:

[far2389]

I just had a batch of aluminum oil filter adapters made for my 4 Tx's. These are the ones that replace the expensive stock filter and use the BMW R65 filter - work great. Have some extra's to sell if anyone interested. Comes with new filters and oring (the other parts are used from the old filter). PM if interested I can email pics.

[lsettle]

I am on the fence to install the BMW filter or the spin on type, I have the spin on set up already.

I did change the oil today, 15w-40 Rotella is what I used. I have the 74 with the oil cooler. Thanks for answering my question about the oil dip stick!

I bought this bike back in May when I was across the world off the coast of Libya, (Canadian Navy). My father went and pick her up for me, a bit of a gamble considering that she was not running at the time, since then I fixed the issues and ridden about 100 miles. She rides nice, she does like around 3000 rpm onward.


Lawrence

[lsettle]

I forgot to include the you tube video of her running for the first time in about 10 years.

http://www.youtube.com/watch?v=0NkTtHC6ZCI

Another question; the tubes going to the oil filter, which tube do I use for the input to the spin on filter and the output? Thanks for the pictures of your setup, Concours!


Lawrence

[concours]

Originally Posted by lsettle

I forgot to include the you tube video of her running for the first time in about 10 years.

http://www.youtube.com/watch?v=0NkTtHC6ZCI

Another question; the tubes going to the oil filter, which tube do I use for the input to the spin on filter and the output? Thanks for the pictures of your setup, Concours!


Lawrence

I forgot now... I have them marked with sharpie. A half stroke of the kick starter showed right away the oil "out" line.

[concours]

Originally Posted by lsettle

I am on the fence to install the BMW filter or the spin on type, I have the spin on set up already.

I did change the oil today, 15w-40 Rotella is what I used. I have the 74 with the oil cooler. Thanks for answering my question about the oil dip stick!

I bought this bike back in May when I was across the world off the coast of Libya, (Canadian Navy). My father went and pick her up for me, a bit of a gamble considering that she was not running at the time, since then I fixed the issues and ridden about 100 miles. She rides nice, she does like around 3000 rpm onward.


Lawrence

She should pull cleanly down to idle, final drive tension is key, your adjustable balancer shaft chain must be set right. That involves removing the oil sump and extension and measureing backlash with an indicator on the tip of the counterweight, then loosening the locknot and adjusting the eccentric shaft JUST A BIT. Carbs are OK? Idle circuit clean and functional?

[SOS]

Originally Posted by concours

She should pull cleanly down to idle, final drive tension is key, your adjustable balancer shaft chain must be set right. That involves removing the oil sump and extension and measureing backlash with an indicator on the tip of the counterweight, then loosening the locknot and adjusting the eccentric shaft JUST A BIT. Carbs are OK? Idle circuit clean and functional?

I've been looking for the adjustment on the balancer. Thanks! I've been through Toby's site and there is a ton of good info there, but I couldn't find any actual adjustment procedure. The on-line fische show the differences, but I haven't taken mine apart to see it in person.

I went through the rest of the motor adjustments and made a simple wiring harness to start it up without frying anything. It started and ran well yesterday. Got a quick adjustment done on the carbs and it idled fine, had good response and seemed smooth. The motor is smoking a bit, but it hasn't run in who knows how long and I did add a fair amount of oil in the cyclinders for the compression test. Also, I do not know if these bikes are prone to wet-sumping like the old brit bikes.

I've got the extended oil sump so hopefully I've also got the balancer mod

[concours]

Originally Posted by SOS

I've been looking for the adjustment on the balancer. Thanks! I've been through Toby's site and there is a ton of good info there, but I couldn't find any actual adjustment procedure. The on-line fische show the differences, but I haven't taken mine apart to see it in person.

I went through the rest of the motor adjustments and made a simple wiring harness to start it up without frying anything. It started and ran well yesterday. Got a quick adjustment done on the carbs and it idled fine, had good response and seemed smooth. The motor is smoking a bit, but it hasn't run in who knows how long and I did add a fair amount of oil in the cyclinders for the compression test. Also, I do not know if these bikes are prone to wet-sumping like the old brit bikes.

I've got the extended oil sump so hopefully I've also got the balancer mod

The retrofits were entirely peicemeal, so sump extension does not mean adjustable chain. The factory and dealers were all over the map with this stuff. Easy to check, look in under your shifter.. BIG hex plug? Or big jam nut woth the shaft having a slot milled in it, and a tab washer to lock the nut? Here are the links to the adjustment procedure:
http://www.tobyfolwick.com/tx750/textual/pbadj_8.php
http://www.tobyfolwick.com/tx750/textual/pbadj_9.php
As for wet sumping, I've never experienced it, and never read anything about it for a TX. One of the Brit "quirks" they solved with some sound engineering.

[SOS]

Thanks a ton! I don't know how I missed it on Toby's site, but I appreciate your help. I just started my own thread so I don't distract from this one.

Thanks Again!