It has been over twenty years since the last Craig Vetter Fuel Economy Run.  You helped to make history.   Maybe it is because it happened so long ago, or maybe it is because fuel availability is looking tenuous, people are interested in how you did it. It is our job to tell them. 

Will you describe your entry?

 The bike: 1983 Suzuki GR650

The size: 650cc

 The modifications you made:    

 1.The concept of the 2-up 650cc minimum [twin] "2-Up Class" class was to be more practical than the Open Class, The Open Class bikes had developed too extreme--- because a bunch of ex-racers all wanted to win! The Open Class bike sat in a corner after the contests and trade shows, too much of a hassle to ride, not to mention the service life of the low friction belt drive was 200 miles!  My “2-Up Class” bike was actually used for commuting [at the time I lived 42 miles from my shop] and it was actually pretty stock: we never took the engine apart for example. It had stock carburetors, frame, suspension, tank, we did have a custom low seat made, smaller handlebars, a big front fender, frame mounted sport touring fairing, saddlebags that were an extension of the fairing streamlining, taller gearing, a custom BUB exhaust system, smaller front wheel, etc.

 What worked? 

 2. The same stuff that worked in the Open Class: less frontal area, better streamlining, taller gearing, etc: in the interest of winning I did feel I had to leave my tall, sexy wife Brenda behind and instead took a tiny girl Sue Gage, who had no motorcycle experience and just hung on for dear life as we scraped around Laguna Seca.

 What did not work?

 3. By this time we were pretty seasoned hands and made few outright mistakes.  There were refinements: the first pipe Denis Manning put on the bike was sort of his standard Triumph solution but on the Suzuki it was way too loud and killed the low end torque right above idle: his 2nd pipe had a tuned crossover and quieter baffles and worked great.

 Can you tell us what mistakes you made so the new generation of builders does not have to make them? 

 4. YES: don't emake the front wheel "solid"-so no air can get thru it like we did with plastic wheel discs--it made the bike handle so badly in corners we had to take the front one right back off--we left the rear one on.

 Did you play around with bore and stroke?  For economy, do we want over square or under square? 

 5. What?

 What about carbs and jetting?  What wisdom can you pass on to future experimenters?

 6. I really messed the carbs up experimenting: Mark at DynoJet really understood the CV carb and got me straightened out: ie: basically back to stock, slightly richer to compensate for a  K&N filter element in the stock airbox.

 What kind of cam worked best? 

 7. After our Yamaha185 experience, we left the cam stock. We tried a  Richard Montanaro grind with less overlap on the 185cc Yamaha and got slightly worse mileage although it really sounded different.

 Did you have to have a special grind?

 8. No 

 Can you recommend a cam or cam grinder by name?

 9. No

 Mufflers… what worked what did not work?

10.BUB ENT made up a set of less restrictive mufflers with a tricky crossover that compensated for the uneven 180 degree twin exhaust pulses that worked great. Denis is an exhaust genius: it's the kind of genius that comes after trying a thousand different experiments. He also has a good eye and marketing savy: ugly pipes don't sell.

 What can you tell us about spark timing?  I believe some of you actually moved your timing around, manually. Can you tell us what worked?

 11. As I recall, the advance curve on this bike was computer controlled, so I think all we did was advance the pickup unit 3 degrees by slotting the mounting holes

 How many speeds were used in your tranny?

 12. Stock-I think it was a six speed

 Did you find that any special oils were beneficial?  What and what brands?

 13. We had free synthetic oil from Klotz

 It is generally believed that false neutrals and or sprag sprockets were used? 

14. No

 Did you have to use an additional jack-shaft to get it geared up?

15. No--I can't even imagine a situation where this would be necessary

 What about wheels and tires?  Big diameter vs small diameter…

 16. On the front we went from a 19" to an 18": you have to be careful here, too much smaller than stock and you lose trail unless you reduce the rear the same amount: since the contest took place on the racetrack we wanted to keep cornering clearance so we could take advantage of the downhill corkscrew without using the brakes, so we kept standard 18" wheels.

 What tire pressure seemed best?

17. Our 185cc experience was negative on high pressure-but we ran 40psi anyway.

 Streamlining:  Do you recall in your testing, the effect of having your streamlined body on versus off?  I think people would like to have some seat of the pants answers for the value of streamlining.

 18. The stock GR659 Suzuki got about 59 mpg.   With  my  sport touring fairing, fender, and saddlebag prototypes  we got up to about 140mpg in testing: to some extent the taller gearing is enabled by the streamlining, so it is a package deal.

Applying your lessons today:

 Today, (2008) if you wanted to build a usable, high mileage machine for real, solo, cross country riding (coast to coast)  please describe  what kind of machine you would start with and what you would do to it: 

 19. One of my favorite motorcycles ever is the  2001 Suzuki SV650  that my son Max built for me from ebay auctions:  with a Parabellum Scout fairing and 15/44t gearing, it gives 60mpg in a bike that I can still enjoy doing track days on; and I wouldn't hesitate to cross the country on it--it's not a hi mileage specific bike at all: just a great all round bike.  This is the thing I think we have to keep in mind--we have to keep the fun in it or what's the point.  as gas prices surge towards $5/gal I may explore something around a 400-500cc twin as the basis for a  true high mileage bike: of course a 250 would be better but I don't think the market is ready.

 What general guidelines can you offer to riders to get better mileage?  The pros and cons of, shifting early, lugging the engine, coasting, tidbits that you can offer to help the new generation.

 20. Don't ask the motor for all it's power: keep the top speeds down; whenever you use the brakes you are wasting money: this really isn't rocket science.

 Are there any ideas you did not try that you think are still worth trying? 

 21. I'm not a motor guy, I asked Bobby Strahlman who was Champion Spark plug's man at the races for advice--everything he told me to do I tried to do and it all worked.

 Tell us a little about what you are doing today?

 22.  www.parabellum.com

Is your Fuel Economy bike still around?  Where?

 23. The Yamaha SR185 was donated to the Smithsonian Museum of American History [Transportation]  The museum is currently closed for extensive renovation but I think is going to reopen later this year.

The Suzuki gr650 was used daily for a year or so and died one day. We called Suzuki who lent us the bike and they wanted it back. That was the last we saw of it.

Thank you so much for taking the time, Charly.  The world needs this information.

 Craig Vetter

Designer