Gaseous Fuel Transfer
Port
- Horizon Gitano
As part of our
ongoing testing of our Gaseous Transferport Fuel Injection System we recently
acquired a road legal Yamaha RS100 in Kuala Lumpur, Malaysia. It was our goal
to convert it on site, and ride it back to our design center in Penang Malaysia
that same day, a distance of 350km. While the fuel injection system is
relatively mature, we wanted to demonstrate that a vehicle could be converted
and immediately placed in service, including a fairly long initial voyage.
The
fuel injection kit consists of a modifies 2-stroke cylinder bore, fuel injector
and fuel pressure regulator, ECU, Throttle body, wiring harness and various
sensors and other parts. Kit cost, excluding the LPG tank should be under 200$,
and will be available for purchase via our partner CEI in the Metro Manila area
starting in September 2012.
In
preparation for the trip we had a shop put together a custom cooking gas
cylinder holder and saddle bag for counter balance. LPG is not sold as a
vehicular fuel in Malaysia so we use commercial cooking gas which is mostly
butane, and comes in 15kg cylinders. Here the tank holder is under going final
touches on one of our Pilipino test bikes before the trip.
I
had to go down to KL to explain the latest E-Vehicle standards to the road
transportation department, so that morning Syaz and Hairy got the “new bike”
(1976 Yamaha RS100), and converted it to fuel injection in the parking lot of
the flat of the former owner, who amusedly watched. There were a few problems
associated with the fact that this bike is actually a US spec bike, and out
parts are designed for the Pilipino version. The CDI wiring had to be changed
out, and it turns out that we had to use back the US spec head, which resulted
in a very high compression ratio.
After
finishing the meeting and the conversion we got back together in the afternoon
and started the bike up. It fired up straight away (converted bikes usually
start on the 1st or 2nd kick after a new install). Test riding the bike we noticed it wasn’t
tuned quite right, and found out that the Throttle Position Sensor had been
miss wired, indicating ½ of the actual throttle position and resulting in under
fueling. This was quickly remedied and we were on our way.
On
the road the bike was running unusually hot, so during a rain brake we looked
into the engine and noticed that the US spec head combined with the Pilipino
piston was giving us very high compression. In a flash of inspiration and good
planning, we decided to put 4 head gaskets on to help space the head out,
reducing the compression to a more manageable level. It was a quick fix, and
worked brilliantly. We ran a little extra fuel (5%) and 2-stroke oil just to
keep the temperatures down a little and provide extra lubrication. Even with
the extra oiling the bike only used about ½ liter of 2 stroke oil for 350km.
Any
time we stopped a crowd would gather around to gawk, and ask questions about
the bike and GXI fueling system. Many were interested in how much power it
makes (about 5% less than the original carbureted bikes), what about fuel
economy (35% reduction in fuel consumption) and cleanliness of the engine parts
(they’re MUCH cleaner running LPG than gasoline) and range (about 1000km on one
15kg tank of LPG). Notable no one asked about smoke (they don’t smoke, where as
the gasoline engine smoke like crazy). Mostly folks were just curious, and very
interested in the whole project and trip.
The
ride back went well, and we only had to stop for rain the one time. We road
mostly at night to avoid traffic and because I like riding at night in the cool
breeze. Indeed it was cold enough to put on a jacket before arriving back in
Penang. Despite the extra, slightly unbalanced weight of the tank the bike
handled surprisingly well in part because we chose to mount it as low as
possible… maybe a bit too low as I occasionally scrape the bottom of the tank
holder on the road in left handed turns! You can see a “bevel” in the lower
edge of the tank holder for “enhanced road clearance”. The bike had ample power
taking most hills in 4th gear even with all the weight and tools in
the saddle bag.
In
the end it was a very successful trip. Even with the non-standard parts we were
able to convert the bike in the morning and ride it back 350km that afternoon,
hardly making a dent in our supply of cooking gas.
Many
thanks go out to those making this EFI Conversion Adventure possible, including
our own Ahmad Syazli, Suhari Mamat, as well as the folks of CEI Philippians: Marte
and Luicito, and CEI US: David, Greg and Bill. We’ll be doing a “Malaysian tour” on our
2-stroke and 4-stroke LPG kits some time in the next few months to really see
how far 1 tank can go.
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