2-Stroke FUN (NGC)

[JJ]

 This would be fun to WAKE UP the neighborhood!!! 

[Canuck750]

I restored one of them about ten years ago, long gone now but it was a fun bike to ride



Same frame and engine as the RD350 that followed with the addition of reed valves, a sixth gear and a front single disc brake

[Huzo]

There is something about THAT smell, that reminds of when life was just a whole lot simpler.
Also the smell of a model aeroplane engine or speedway bike on the old Castrol R...

[Antietam Classic Cycle]

The bike I owned when I got my license was the 250 version, the YDS7. 

[radguzzi]

Geez Canuck, that is a great restoration effort. 

One-a these days I dig this out again, it will need crank seals and a good going through.  '84 RZ350N

Cheers,
Rob

[Canuck750]

Geez Canuck, that is a great restoration effort. 

One-a these days I dig this out again, it will need crank seals and a good going through.  '84 RZ350N

Cheers,
Rob

That is a rocket! Very nice, I bet it sounds fantastic on full boil.

[JJ]

Had one of these from *brand new*, back in the day...Blue, just like this example!

1977 Yamaha RD400...It was a good bike...6-speed and very quick for it's size.

..sometimes referred to as "The Giant Killer"...and for good reason...

[radguzzi]

That is a rocket! Very nice, I bet it sounds fantastic on full boil.

It actually howls however, I would seldom twist it up there... just a ridiculous little powerhouse, for the year.  Still fun to ride though.

rad__

[Roebling3]

There's a blue '77 RD hiding from winter (w/DCT chambers), in the basement, w/a 4LS, GT500 Cafe`w/Higgspeed trombones, RS125 Aprilia, Gilera CX125. I've used Amsoil Interceptor 2 stroke oil for years. As they used to say; they go like stink. Sometimes I light a wick of pharma grade Castor to improve the shop atmosphere.   R3~

[Cdn850T5NT]

I would REALLY love to have one of these...

The 1969 - 1975 Suzuki T500 twin.  Considerably different by way of behaviour compared to many two-strokes... in that this bike tends to be pretty low-reving, does not foul plugs, gets pretty darned-good gas mileage.  Also, the bottom-end is hella-robust.  The CCI system - Suzuki's CrankCase Injection delivers positive, pressure-fed oil to the two outboard main bearings (and by way of a routing system, to the two crankpins / bearings).  The centre main is lubricated by gearbox oil... with a trough system.  The kinds of mileages you can get without having to replace the bearings are very substantial.  Of course, a two stroke really needs to have intact, well-functioning oil seals on the crankshaft... so you have to do two types of leakdown testing:  one for crankcase pressure integrity (typically has to hold 6 or so psi for 5 mins) and then also the piston rings / cylinder / head gasket leakdown.

The is a BIG following of two-stroke twins in the UK.  The Suzuki T500 is one of their favorites.

[JJ]

Agreed...that is one big, beautiful 2-stroke "smoker!"

...and I'll bet it's a BLAST to ride fast!!

[Cdn850T5NT]

Just to bring back the two-stroke multi-cylinder discussion (please humour me) - this Suzuki T500 has, of course, a built-up crankshaft.  That DOES make a multicylinder  2 stroke a bit of a PITA... and particularly in this case of the T500 - because the centre-section of this twin has to be "phased" correctly.  Now the Yamaha RD, by comparison, has a splined centre section, but the Suzuki is NOT splined...  and so you have to press it together (around the one-piece centre bearing + 2 centre-seals "element" - in a manner that the two cylinders are properly at 180 degrees apart.  Many people scribe lines on the still-assembled crank-wheels and then seek to align those scribe-lines on reassembly...  I'm not sure that this is accurate enough.

There are ways of pressing the centre-section together to ensure that it IS phased accurately - by using an assembly jig. Probably the best ones use a piece of pipe and guide-plates that have keyways or pins.  Another way is via the attached photo... that a fellow made up for his Yamaha Banshee.  A pretty over-the-top effort to do this accurately.

The effective other way to get this done is to go to an established expert with 2 stroke multi's...  Apparently "Ed Toomey Designs" is one such expert with a reputation.  I can't help but think that the relative infrequency with which this has to be done does not merit coming up with one's own jig.  Toomey has a rep. of having good jigs.
 





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[Roebling3]

Huzo says 'Castrol R'! - and yanks me back by the ears. One of my earlier 2 strokes was a Bultaco. '61, 2? Black/silver. I used to heat the muffler in tri sodium phosphate to get rid of the oil blocking the exhaust flow. And then there was rust.  R3~