Two Stroke, Motorcycles.

[vernon]

Unleaded is fine in any two stroke.
The 'Lead' is added to fuel to aid seat life of the valves in a four stroke engine. 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.

Here's the last two stroke I built and raced. I managed 2 1/2 laps of a 3 lap race on the Isle of Man TT course before the primary drive chain exploded at Ballaugh! The engine was OK though.

Wow! A Cotton! The last Cotton that I saw was a Villiers engined Cotton trials bike back in the seventies.

 

[Dirk]

Here's one for all you Kawasaki triple lovers - LOL

View: http://youtu.be/6ratfuML9QA
I think cylinder 27 sounds a bit rough.......

 

[Billy Wizz]

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.

Here's the last two stroke I built and raced. I managed 2 1/2 laps of a 3 lap race on the Isle of Man TT course before the primary drive chain exploded at Ballaugh! The engine was OK though.

That is lovely, my only claim to fame as far as the TT is concerned me and my mate, butch did a flying lap in a transit van, well not exactly flying but we made all the great noises lol.

 

[Billy Wizz]

Here's one for all you Kawasaki triple lovers - LOL

View: http://youtu.be/6ratfuML9QA
I think cylinder 27 sounds a bit rough.......

I remember a guy in Wales built a v 6 two kh 250 s welded together I loved the mad old inventive years that have gone.
I think 27 sounds fine, lol.
Kawasaki spitfire comes to mind.

 

[FrankCrank]

...fella at the place I did my apprenticeship had a Silk 2-stroke - quite a rare bike I believe.....

 

[Dirk]

...fella at the place I did my apprenticeship had a Silk 2-stroke - quite a rare bike I believe.....

Remember seeing a few of them on the road in the Isle of Man in the late 70s/ early 80s.
Based on the Scott 600 twin and made by George Silk.
https://en.wikipedia.org/wiki/Silk_Engineering
Clive Waye used the same basic engine in his SKF 'RaceWaye' race bike. A pal of mine, Nigel Rollason, rode it at the TT in 1975.

 

[Billy Wizz]

...fella at the place I did my apprenticeship had a Silk 2-stroke - quite a rare bike I believe.....

I remember them pretty expensive if I recall

 

[vernon]

Here's one for all you Kawasaki triple lovers - LOL

View: http://youtu.be/6ratfuML9QA
I think cylinder 27 sounds a bit rough.......

I wonder how many gallons to the mile it does.

 

[Piemaster]

I would love a 2-stroke at the moment - but not for a bike. Sodding outboard engine in ships rescue boat is a 4-stroke efi and currently running on 1 of 3 cylinders. Given a 2-stroke and a carb I might have a chance of getting it to run, but an EFi that lives outside year round 24/7 on a ship. Nope.

 

[Billy Wizz]

I wonder how many gallons to the mile it does.

quite a lot..?

 

[matiz]

The only 2 strokesI've owned were a bantam and Ariel Leader but I always lusted after a "kettle"

 

[vernon]

View attachment 116909 The only 2 strokesI've owned were a bantam and Ariel Leader but I always lusted after a "kettle"

Had a several Bantams, an Ariel Leader, an RD200 Yamaha, an RD250LC Yamaha and a Suzuki B100P. The 'kettle' looked awesome in its day but handled like a pig. My RD250LC would give one a run for its money on twisty windy roads.

 

[Oldfentiger]

Anyone interested in two strokes would enjoy reading "Stealing Speed" by Matt Oxley.
It starts by explaining the origins of expansion pipe technology being the V1 pulse jet of WW2 fame.

 

[Firestorm]

View attachment 116909 The only 2 strokesI've owned were a bantam and Ariel Leader but I always lusted after a "kettle"

I have always wanted a Kettle, either standard or, for some odd reason , In Texaco Heron livery.
Had two strokes for years GT 125 , Rd 250 and 400.
Would have loved either of the 4 cylinder 500s RG or RD, or a 350ypvs as well

 

[hondated]

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.

Here's the last two stroke I built and raced. I managed 2 1/2 laps of a 3 lap race on the Isle of Man TT course before the primary drive chain exploded at Ballaugh! The engine was OK though.

Not being much of a mechanic Dirk I loved 2 strokes as decoking the head was so easy. Unlike my current BMW GS1200.