Two Stroke, Motorcycles.

[Billy Wizz]

I am 53 years of age and i think i just missed the peak of motorcycle madness in the late 70s.
i owned a few Kawasaki triples around that time but always wanted a road going TZ 750, probably the best motorcycle ever built.

Trawling through YT i came across this, my all time favorite, second best bike rider ever, i remember this bike being banned, nice reunion 30 odd years later. https://www.youtube.com/results?search_query=kenny+roberts+tz750+flat+tracker

 

[steveindenmark]

I dont think that 750 is a 2 stroke Billy.

 

[Billy Wizz]

I dont think that 750 is a 2 stroke Billy.

Ok what makes you think it isn't, my friend.

 

[Dirk]

Kenny Roberts flat tracker was definitely a Yamaha TZ 750 two stroke.
I love all TZs. I worked on loads and raced a 350 for several years - great fun!

 

[steveindenmark]

Ok. Its a bit bigger than my Moto Guzzi Trotter and Moto Guzzi Cardellino, which are both 2 strokes :0)

I didnt know they made such big 2 stroke bikes. Its good to learn things :0)

 

[raleighnut]

I dont think that 750 is a 2 stroke Billy.

It most certainly is, its a 4 cylinder watercooled 2 stroke. I know a couple of fellas who used them in racing sidecar outfits, unreal power.

 

[Dirk]

Awesome in their day but a modern 600 cc four stroke pumps out around the same horsepower.
Don't sound or smell as good though!

 

[MarkF]

I am 53 too and had many my 2 strokes in the '70's, FSiE, RD125, RD200, RD250, KH250, KH400, I loved the sound and smell. Nowadays I just have a Vespa 150.

 

[Smokin Joe]

Older two strokes don't like unleaded petrol.

 

[Billy Wizz]

Older two strokes don't like unleaded petrol.

That is what is putting me off pulling the trigger on a old classic, i believe there are additives, but a bit out of touch.

 

[steve50]

I gave up riding motorcycles many years ago, that yamaha 750 two stroke was real old school , raw power that required real skills to ride and control. they certainly don't make them like they used to. Modern motorcycles are far more refined and balanced, yes you can get massively powered bikes but dare I say they are "safer" to ride as long as the rider rides sensibly.

 

[vernon]

I gave up riding motorcycles many years ago, that yamaha 750 two stroke was real old school , raw power that required real skills to ride and control. they certainly don't make them like they used to. Modern motorcycles are far more refined and balanced, yes you can get massively powered bikes but dare I say they are "safer" to ride as long as the rider rides sensibly.

All motorcycles are safer to ride as long as the rider rides sensibly.

 

[Billy Wizz]

Awesome in their day but a modern 600 cc four stroke pumps out around the same horsepower.
Don't sound or smell as good though!

Easy to ride too, makes me marvel more about the pioneers of motorcycling.

 

[Dirk]

Older two strokes don't like unleaded petrol.

Unleaded is fine in any two stroke.
The 'Lead' was added to fuel to aid seat life of the valves in old four stroke engines. Modern engines get around the valve seat wear issue through material technology ie.using different steel alloys. A two stroke does not have valves. One of the main causes of plug 'whiskering' on two strokes is the use of Leaded fuel which leaves deposits on the electrodes.
I have built countless engines over the years, vintage and modern, road and racing and have yet to come across a two stroke that, properly set up, had any problems running unleaded fuel.
The biggest mistake most people make, with a two stroke, is adding extra oil into the fuel 'to be safe'; without adjusting the jetting to account for the altered fuel/air ratio and then wondering why it's not running properly. Too much oil in the fuel will make the engine run 'lean' and therefore hotter. You would be risking detonation, piston damage or even seizure.

 

[Dirk]

Here's an interesting site for Yamaha TZ lovers.
http://www.tz350.net/