Yamaha YICS-Good for fuel economy

Have you ever wondered what YICS is? Why is it blazoned into the covers on the engine of your older Yamaha motorcycles? Is it like Wonder Bread? Does it make your bike run farther, jump higher, and outrun the bad guys? Yamaha introduced Yamaha Induction Control System in 1979 as a fuel-saving engine system in 4-stroke motors. As stated in an earlier post, some of the most fuel efficient motorcycles were of the late 70s and 80s. How does it work? The following is a summary of the system from a Yamaha service manual.  "The YICS  consists of 2 separate chambers, each connected, by a hose, to a port on each cylinder just behind the intake valve.  As the piston moves down on the intake stroke, the cylinder fills with a fresh air/fuel charge.  A vacuum is created in the YICS chamber at the same time.  When the intake valve closes, part of the charge is drawn into the YICS.  When the intake valve reopens the mixture in the YICS shoots back out through an angled tube into the cylinder, mixing with and swirling the main intake charge.  The swirling charge is then compressed and ignited, burning more completely and producing more power than that of a conventional engine."
With this in mind, also note that many owners of XJ bikes recommend using high octane fuel, or a good fuel cleaner to keep the YICS tubes from getting clogged. I recommend using a product called FP60 by www.LCDINC.com  On their website the following benefits are claimed for their fuel additive:

• Antioxidant and solvent properties scavenge water and moisture from the oil and fuel systems
• Emulsifies carbon and varnish and most other "gunk"
• Stabilizes the fuel, allowing more efficient burn in the combustion chamber
• Lowers fuel mixture freezing points
• Reduces carbon dioxide and NOX emissions up to 30%
• Leaves a thin, protective coat of oil over vital fuel system parts, including fuel pump, gas tank and fuel injectors.

I've been using FP60 for four years and have had great success with it. Seca turbo fairing, headlight cover, YICS, and a fuel additive....does it all add up to 58 miles per gallon on the Seca 900?  My tests say yes.

How to improve motorcycle MPG

We want to thank all those who read, post, and comment on our Facebook, Twitter, and Blog. As we build the Retro Motorcycle Blog community, your insights, and input is valuable to us. This video is in response to a question asked by one of our readers...."how did you get the Prototype 900 Seca-SST to improve its fuel economy from 52 MPG to 58 MPG?"  This video was created to respond to that question.  If you wonder over to Aptera's website you'll read how important aerodynamics and weight are to improving MPG. We believe by applying three aerodynamic fixtures to the Yamaha 900 we achieved the 6 MPG increase. They are:  1. fitting the 1982/83 Yamaha XJ650 Turbo Seca fairing to the 1983 Yamaha XJ900 Seca.  2. MRA flip screen.   3. Plexiglas shield to headlight recess area.

Also, for another post, is the system Yamaha engineered for this era of bike.....YCIS.  Few remember that in the late 1970s and early 80s we had the second fuel crisis and fuel economy was on every bodies mind.  Yamaha had a clever solution....stay tuned.