Diff'rent Strokers

[Eddiej]

Firstly, I would like to thank Greg and the Forum members of TZ350.com for supplying some of the the info below.

Please add your own TA125 details and any info that you may have hiding

The history lesson..

In 1974 Yamaha released it's first production 125cc road race bike, the TA125. It was sold as a Clubman level bike.

The TA125 has a twin cylinder, air cooled, two stroke engine and was based on the twin shock AS-3 road bike.

It came fitted with CS2 front forks, DS6 front brake and front wheel. Other items specific to the model included fairing, seat unit, brackets and tank.
Other differences over the AS3 include the seat mounting , which on the AS3 are small tubes welded to the top of the rear frame in formed depressions. The TA125 has drilled bushes that pass through the centre of these tubes. It also has a brake lug on the Left hand side, so that the shift and brake pattern can be reversed, it also came with a welded front tank mount. And different coil mounts.

The engine was pretty much AS3 with modifications to porting and chrome lining to the bores. Carburetor and exhaust mountings were also different. The exhaust is secured by springs in place of bolts. I cannot presently remember the difference with the carburetor mounts .
The compression ratio was changed on the TA125 and with the combination of new exhaust, pistons, rods, 28mm carbs, close ratio box, and Hitachi CDI ignition system the boosted output was a dizzy 24BHP at 12,500rpm. Further RPM and power were available using kit parts. Cases were also strengthened around the main end journals.
The TA125 came with a 5 speed box as standard, there were also factory 6 speed boxes and 7 speed boxes for road use.

Along with many other early race bikes, the TA125, is quite a rare bike, and they are hardly ever seen for sale on the open market.

There does not appear to be a significant amount of information about TA125’s, but I shall expand and edit the above as further information is gathered.

My TA125 was purchased about this time last year and although they were released for sale in 1974, I have discovered that the bike that I own is number 100 and was released in Japan in 1973. An interesting side note is that I have now located bike 101 which was first sold in the USA in 1975 and is still being raced in an American National series.
I know very little about the history of my bike except that it appears to have remained in Japan up until last year.
Whilst you may look at it and think "what a state" the bike is going to be a fairly straight forward restoration, thankfully the rare aluminium fairing bottom, still intact and in good condition.
The bike looks to have done very little over the years, nuts and bolts show no sign of abuse and even the tyres are the original all or nothing V pattern.
The bike is now fully stripped for rebuild, every nut, bolt and fitting is being blasted and re plated, the frame and fairing brackets are being blasted and then stove enamelled, the wheels are the only item still in one piece but they will shortly under go a full strip, vapour blast and re lace. The engine is also away being rebuilt and sadly upon inspection one piston is the worse for wear. I had assumed that it may be a big end gone AWOL, but it is looking as though it is something else. I shall up date that as soon as I know. I have also stripped the front forks as they need to be re plated.
Although in good condition, I want to buy a new set of plastics for the bike, and once these have arrived, they along with the tank shall be going off to Rob Garland to be painted.
The only problem to date with the rebuild is finding some rear shocks. I was going to strip them, have them re chromed and re use them. Sadly it is not possible to take them apart and I am coming up blank as far getting another exact set is concerned. I have been told that AS3 ones are almost the same when the shroud is removed. Also early RD125's are a very close match in appearance

I shall add more to the above as I either carry the work out or remember items!















OUCH!!



The rebuild has ground to a halt, whilst I wait for the rest of the parts to be returned from the platers etc, but I still could not resist starting a loose assembly of the parts that I do have..

The tacho rubbers still need to be replaced, along with the castle nuts as they did not re plate very well. The down side is that the four rubbers cost £15.00p each. I could get away with leaving them, but it would just niggle me if I did not replace them.

[willbloke]

Nice one Eddie !
I sold a mate an RD125 and he's set on building a TA replica , these pics will help him a lot !

How much did it cost to get all the bolts/spindles etc plated ?
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Piston broke ....

Any Aspes bits ? PM me .

[Yatsushiro]

Eddie

Another impressive rebuild/recovery...

With the work you undertake, you must have a list of good and trusted suppliers for powdercoating, painting, plating etc.

Care to share ?

Thanks

Paul
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[Eddiej]

Thanks for the replies and sorry that I have only just found them!

there seems to be a coupe of people currently buildings replicas, I saw an old TA petrol tank sell on ebay this week for £563.00p!!

As far as platers etc go, I shall pop some info up for you shortly.

[bluemistjunkie]

Very nice work Eddie. Can't wait to see the finished example.

Love to see these classic racers brought back to their former glory. Are you planning to race it yourself at all?
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Prospective RD125LC buyer.

[Eddiej]

Not really very much to report. I am still waiting for the wheels to be returned from being re laced and have finally managed to get hold of some rear shocks, although sadly they have no preload adjustment.
On the plating side of things, there has been a mishap and some parts have gone missing! Paintwork wise, I have managed to clean the tank up and feel very happy with the result of this, so it just leaves the new seat unit and fairing to get painted.