TZ Yamahas 50 years old this year

According to Road Racing World Magazine the Yamaha TZ racebikes are 50 years old this month!

Does anyone know why Yamaha called them TZs or indeed why the previous air-cooled models were TD and TR? Does T mean Twin?

Why were some bikes designated YZRs? I know most YZRs were works bikes, but not all I think, and also mostly the works bikes were called OWs, which I always thought meant Official Works.

Mine's 49 years old -1974

Apparently the motocross YZ series stood for - 'Yamaha Zinger' - well sounds as plausible as anything (Really?????????)

So perhaps TZ stands for 'Tarmac Zinger' (         )

So YZR obviously stands for 'Yamaha Zinger Racer'.

As for OW well who knows. (Oh Well)
Been around TZ since the start and I will admit I never thought about these, other than it has probably some incomprehensible Japanese (well to non Japanese) meaning.

I would like to know more 

Considering that the TZ was the most significant readily and affordable to many available competitive racing machine in the past 50 years I am surprised at the lack of interest in this topic.

Seems that there is more interest in who is related to who or how they might have started in racing.

The TZ series of racing machines manufactured by Yamaha form 1973 to its' sad demise in 2006 (ish) were arguably the machines that led to the best era of motorcycle racing, from club to GPs that ever existed or will ever exist.

It can be argued that the TD2 and TR2 were even more significant because they were the first of the production racers that could be purchased by the public form your local Yamaha agent on which riders of non-works exotica could challenge the established front runners on their works machines.

What an era they led to. I well remember the days when you'd turn up with a 350 TZ to find 120 others vying for a first 14 in the 5 lap heat to qualify for the final.

National standard race meetings almost every weekend with more than one club meeting every weekend in the season. At least at a club meeting more than one 5 lap dash was guaranteed. 

Ask 'top men' of today what they would have liked to race -  a 250 two stroke grand prix machine. 

Never see it again - sadly          

I have to admit the best looking TZ for me was the Reverse Cylinder model.

Here is a Yamaha spec sheet for it with a great unfaired pic showing the reverse cylinder layout https://global.yamah...AP000142580.pdf

I still haven't figured out what the TZ, TD or TR  model numbers stood for, although I did find this for Yamaha outboard motors. https://www.yamaha-m...he-model-codes/

This would suggest that the T stands for Two stroke which would fit with the TD, TR and TZ designation. The document also suggests that the second letter also relates to engine type. I can't figure out how the TD and TR engines differed in engine type, but they are just before my time. However, the main difference between the TZs and the TDs and TRs was that they were water-cooled and this was common for all TZs. Perhaps Z means water-cooled.

Edited by brands77, 06 April 2023 - 13:05.

Who knows the vagaries of the oriental mind   . 

What I do know is they were the savior of racing in this country for nie on 30 years and had it not been for the evil empire (Honda who did produce some great two strokes)  insisting that GP racing should be four strokes (their first love) then we might still have these wonderfully simple engines instead of the totally ungreen four stroke monstrosities with their unnecessarily expensive, in the way of part count, thus manufacturing energy consumption etc. Don't give me the exhaust pollution story as this with modern two strokes is less than with four strokes or the myth of the 'electric' crap which is unsustainable even with modern battery technology.               

Talking of which, despite the investment made by Ducati the MOTO E bikes can now do 7 laps as quick as a Moto 3 250cc single.    

Feet are the way forward and I have two of them making me a two stroke       

Edited by tonyed, 06 April 2023 - 15:23.

 I can't figure out how the TD and TR engines differed in engine type, but they are just before my time.

I think the bikes were the same apart from the TD being a 250 and the TR a 350.

The TD2 and the TR2 were totally different engine wise.

Like the TZ250 and 350 the TD3 and TR3 were very similar to each other save the top end, primary drive ratios and exhausts the TZ of course being water cooled versions of the TD3/TR3.

There was a TA as well. I think it was the air cooled 125cc, but I have heard there was a 250 or 350 version. I have heard this was a TD engine in a TZ frame and released just before the TZs, but it is a bit before my time. I am correct in thinking this?

The TA was a 125 air cooled race kitted version of road bike. A little more than just a GYT kit but lacked the sophistication of the TZ.

There was an interim version of the TZ250 released. The TZ350 arrived in 1973 in time for the Daytona 200 in March of that year and Jarno Saarinen took it to victory.

The TZ250 was tardy but did arrive late in 1973, most 250As were 1974 machines.

The interim model was the TA250 (I believe, I should know better) and featured aircooled top end with radiator brackets, I believe that Yamaha did later offer the water-cooled conversion at a knock down price.

It might have been a TZ250 but with a wet clutch. I used to know all this.

I also believe that some of the earlier aircooled TD3s were supplied with wet clutches. Typical of Yamaha at the time.

What was in the parts bin was fitted.

i have a warning to you all out there DON'T GROW OLD, EVERYTHING PACKS UP AND THE NEXT THING YOU KNOW IS YOU DON'T KNOW!!!!!!!!!!!!!!!!!!!!!!     

Yes, the TZ250s were delayed until later in 1973 and, in the interim, production models were sold with TD3 engines in a TZ frame (complete with radiator brackets, as you say); these were designated by Yamaha as TA250s. I bought a TD3 (dry clutch) in the winter of 1975/76 and was surprised to find that it had radiator brackets fitted. I don't know this for certain, but I strongly suspect it was one of these. It came with a Padgett liveried fairing (which I subsequently destroyed in an 'off'!).

I can recall during the 1974 UK season, TZ350's started to appear in numbers.   I remember getting a close up of one at that years TT. The engine was dismantled, and I was impressed with the water cooling elements of the design.  It looked a big step forwards in reliability compared to the TR3.  Well, that was June and by August I was taking delivery of one of the first six TZ250's to be imported.  Took the Thames 400E up to Chandos Pole Street in Derby where John Cooper gave me the choice of any of the six crates.  With a spares kit, contained within the wooden crate, it came to £1836. including VAT.  Happy days.   I made a bike bench out of the base of the wooden crate and still use that today.    

I can recall during the 1974 UK season, TZ350's started to appear in numbers.   I remember getting a close up of one at that years TT. The engine was dismantled, and I was impressed with the water cooling elements of the design.  It looked a big step forwards in reliability compared to the TR3.  Well, that was June and by August I was taking delivery of one of the first six TZ250's to be imported.  Took the Thames 400E up to Chandos Pole Street in Derby where John Cooper gave me the choice of any of the six crates.  With a spares kit, contained within the wooden crate, it came to £1836. including VAT.  Happy days.   I made a bike bench out of the base of the wooden crate and still use that today.    

I remember you having what I think was your first ride on it at an ASTRA meeting at Lydden.  I've a photo of me sitting on it at that meeting somewhere.

Edited by Robin127, 12 April 2023 - 01:49.

Pete:

Take the Velo off the crate, reassemble it and we'll put my A in it take it back to JC and demand your money back, plus interest    

I remember you having what I think was your first ride on it at an ASTRA meeting at Lydden.  I've a photo of me sitting on it at that meeting somewhere.

I can vaguely remember that first ride.  Used to a Formula Bantam round there, it was absolutely terrifying.    But I soon got used to it. 

Those first TZ250's came with the gearchange shaft on the left - no good for me. So there was an 11th hour strip down and extraction of said shaft. A quick hacksaw and re-weld saw it poking out of the primary gear case.    The following years bikes (TZ250B) came with a splined gear shaft sticking out of both sides.   I had to wait until I got Bob Towse's TZ250C in August 1976 to enjoy that configuration.   

Yes I have 'British' feet as well.

The 'A' and 'B' had the RD 278 shaft after that they all had the 383 double ended shaft.

Tried riding my A at Mallory a couple of years back with the change on the left.

Hopeless, the number of times I tried exiting the hairpin in top gear having shifted using the gear lever instead of the rear brake.   

As the standard shift shaft spline used by Yamaha for numerous bikes is a 12mm dia it's easy enough to get an old shaft off  almost anything and cut and weld it to make a 383.

Any idea what happened to the Towse bros?

Yes I have 'British' feet as well.

The 'A' and 'B' had the RD 278 shaft after that they all had the 383 double ended shaft.

Tried riding my A at Mallory a couple of years back with the change on the left.

Hopeless, the number of times I tried exiting the hairpin in top gear having shifted using the gear lever instead of the rear brake.   

As the standard shift shaft spline used by Yamaha for numerous bikes is a 12mm dia it's easy enough to get an old shaft off  almost anything and cut and weld it to make a 383.

Any idea what happened to the Towse bros?

I stand corrected Tony.  Memory can play funny tricks. Regarding the Towse Bros , I was in conversation with the late Tom Dickie to get Bob's number, but unfortunately was too late . Bob had big associations with the Farnham Royal Club I seem to recall.   

Edited by Macca, 16 April 2023 - 20:35.

Unfortunately Greg has 'shelved' this site now. The 'data' is still there but not the forum 'TZ Discussion'

Purely a non-technical comment - in period I really enjoyed watching the various TD bikes race and admiring them when static - to me they just looked right and sounded right 

Nice video here of Steve Baker talking about the Yamahas he rode. Not too much new or inside info (it's short), but the TZ750 sounds really great on the video

Still younger than me though.

Just got a 1978 TZ 350 E.

The wheels and Spondon swinging arm are out of my E from the early 80s, MGP replica on this one, the rest is the one Mr Godward and I took to Daytona in 1981 for a 'free' holiday.

What a series of machines.

Never mind, Manxes, 7Rs, G50s, KTTs, all great bikes but pale compared with the GOAT. The TZ                     

There will never be the like again, I assure you.      

Edited by tonyed, 21 July 2023 - 00:25.

I remember the TZ 700 being considered far too powerful for Joe Bloggs to race and there were attempts to restrict it's use to top riders only.  What would they make of today's 250 hp monsters?

The difference today is that the 250bhp monster have a frame and suspension, brakes and tyres. Back when the TZ700 had excuses for a frame, suspension, wheels and tyres.

It's not so much the power but the way it is transmitted to the road.

I can vaguely remember that first ride.  Used to a Formula Bantam round there, it was absolutely terrifying.    But I soon got used to it. 

 

Those first TZ250's came with the gearchange shaft on the left - no good for me. So there was an 11th hour strip down and extraction of said shaft. A quick hacksaw and re-weld saw it poking out of the primary gear case.    The following years bikes (TZ250B) came with a splined gear shaft sticking out of both sides.   I had to wait until I got Bob Towse's TZ250C in August 1976 to enjoy that configuration.   

I bet you still have the Yokahama (Jokeahama) tyres that came with the bike. Secreted away just in case 

Bumped into Bob Towes's brother at Stafford in April.   

Like Bozo Johnson I've just managed to unlock my old phone. It said 'press button B to get your money back' 

Edited by tonyed, 23 July 2023 - 17:39.