Some of this is obvious, but I want to stress it anyway. If you are having doubts about your MPG, there are a few things you need to make sure of. For those of you with Power Commanders, it is best to follow this procedure first, then set the PC. Also, this all assumes that your EFI system isn't having any technical problems.
First, make sure your throttle bodies are sync'd as closely as possible, using either mercury sticks or a digital equivalent. By sync'd I mean air bypass screws, throttle body left to right from 2500-3000, and idle. It's tricky to get it exactly right, and when the bike gets too hot it's even harder.
Second, for FI bikes '98 and before, find a shop with an Exhaust Gas Analyzer, and someone that knows how to access the trim screw. For '99 and later bikes, find a Guzzi shop that has an EGA AND the Marelli MDST, that is used to set the trim.
Have the mixture set by either the trim screw, or the MDST, CORRECTLY, using the gas analyzer, checking the CO%. Each model has it's own best setting, and of course each bike will vary, especially if the exhaust/intake/chip have been changed. The trim is claimed to only affect up to 1800 or so RPM's, but in my experience, it actually affects closer to 3000. This will affect gas mileage, depending on how you choose to set the bike up. You may choose to sacrifice performance for mileage, or vice versa, etc.
I won't get into specifics for each model, nor will I list the entire procedure, but I do have my notes with what I've found to be the best settings for each model, including aftermarket parts added.
Third and most important-- DO NOT let a dealer or shop tell you that none of this is important. Too many times have I seen new bikes from other dealers come in running like crap or getting terrible mileage, only to find that the entire EFI system was never setup right. The things mentioned above can make your Guzzi run like it's supposed to, and get the best MPG possible. If your tuning or mpg is questionable, please take your bike to a qualified Guzzi technician who understands the way it works. After all of this is checked, and you still have bad mileage, then either your bike has a real technical problem, or there are of course, the usuals-- weight, wind, over use of throttle, doing 25 mph in 5th gear, trusting your fuel light, doing 75 mph in 1st gear, only putting one plug cap on, putting diesel in instead of petrol, holding your foot down on the brake pedal, etc. etc. etc. .......
Sean Fader
truckasaurus@webtv.net
