RE: 1970's Yamaha & Suzuki enduros - 2

Thanks so much for the compliment. The water-cooled 750cc big brother was the one they called the "Water Buffalo". These 550s are air-cooled and had the Ram Air cover over the cylinder heads and the first-ever attempted emissions device that cut down smoking by recirculating unused oil under the pistons into the combustion chamber of the cylinders that were on their combustion stroke. The noise it makes is heavenly. Fun little bike.

Am with you, the sound of 2T bikes is intoxicating.
Here is a short clip of my second RZ500 with few mods. I used to live in Texas and those monster bikes were very rare to find so I attracted lots of attention with the natives.

https://www.youtube.com/watch?v=pqyBRRO-xuk

This clip was shot in 1997, so very low res, but sound is ok.

The Water Buffalo was the water cooled GT750 triple. The RE5 wankel / rotary was another unique Suzuki product of that era

Zitat von CK_AZ_SB im Beitrag #16

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Thanks so much for the compliment. The water-cooled 750cc big brother was the one they called the "Water Buffalo". These 550s are air-cooled and had the Ram Air cover over the cylinder heads and the first-ever attempted emissions device that cut down smoking by recirculating unused oil under the pistons into the combustion chamber of the cylinders that were on their combustion stroke. The noise it makes is heavenly. Fun little bike.

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Here ya go...as taken from the Wikipedia page for these bikes:

Visible emissions control
Suzuki Recycle Injection System (SRIS) was an attempt by the manufacturer to reduce visible emissions from a two-stroke motorcycle. The SRIS consisted of a small check valve in the bottom of each crank chamber along with various lengths of elastomeric tubing to the transfer ports of adjacent cylinders. See the attached diagram for a graphic depiction of the system. Two-stroke engines have a tendency to collect unburnt oil and fuel in the bottom of the crank chamber at idle. Upon acceleration, after a period of idling, the unburned oil and fuel gets sucked up the transfer ports and contributes to an overrich mixture for the first 5 to 10 seconds resulting in a smokescreen from the exhaust. The SRIS plumbing routed the unburned fuel and oil to the next cylinder in the firing order thus allowing it to mix more thoroughly with the incoming charge of that cylinder and lowering the production of visible smoke. Overall fuel and oil consumption was unchanged but visible smoke was greatly reduced on sudden acceleration from rest.[7]

sr48.jpg - Bild entfernt (keine Rechte)

On my 1963 Yamaha YD3 250cc "touring" bike, that ran a mixture of 4% oil in the gas, the oil would build up in the bottom of the crankcase and when I hit the freeway and opened up the throttle I would look in my rear view mirrors and see nothing but a huge cloud of blue smoke - right before the spark plugs would foul. I think the Suzuki system, along with its injection pump, was likely a big improvement over the Yamaha. But it probably didn't kill as many mosquitoes as did my bike.