How do you figure Fred? what you accomplished with a shim, can be accomplished by moving the air/fuel mixture at rpm up/down relative to the throttle position
All you can change with the fuel map is alter how wide the fuel injector pulses are at a given throttle position setting. You can't add or subtract air flow, as that is controlled by the throttle plates themselves. Once the throttle plates begin to open and the engine is off idle, they are the single controlling element for air flow rate changes. Fuel management is there to provide the proper ratio of fuel for the given amount of air coming in, and that ratio is kept in a very narrow range to provide for efficient and clean engine operation and fuel burn.
So the only thing you could do to try to smooth it out with a change to the fuel map, would be to add LOTS of fuel, and make the mixture way overly rich to the point that the engine is near stalling out - in a feeble attempt to tone down the power output at low rpms. The overly rich mixture can and will cause other problems and will most likely result in more carbon build up on your valves and pistons over time as well as possibly clogging up the catalytic converters. The purpose of fine tuning an engine map is for making very small adjustments to correct lean surging or flat spots, not for making large whole scale changes to it. Furthermore, I suspect you would find that there isn't enough adjustability in the map to overcome the airflow rate, so you probably wouldn't be successful anyway.
The manufacture of any vehicle spends literally hundreds of hours with engines on dynos and high dollar (4 gas) gas analyzers as well as on a test track before they get the ignition timing and fuel maps all dialed in for best engine operation, fuel burn, emissions, and drive ability. While it may be set in some respects with regards to emissions, overall it will be a very well developed fuel map that will result in long vehicle life, and efficient and smooth engine operation.
The root cause of the problem is that the throttle plates open too far and too fast at small throttle grip angles, and the reason this happens is the progressive pulley. This causes large scale changes to the incoming air flow rates and very small changes in the throttle grip result in larger changes at the throttle plates, making it hard to control the bike at low rpms.
I am sure there are plenty of other ways to fix the throttle pulley than using the copper shim like I did. You could probably remove the pulley from the throttle body and you would be able to work on it better. I made certain when I put the shim in mine that there was no way it could come out, and I very carefully shaped it to fit the pulley and stay held in, so it is more like a custom made part for the pulley, and is not a "piece of FOD" just jammed in the throttles. FOD is defined as a Foreign Object, this is a custom made part designed with a purpose and made to fit and held securely in place.
Someone else used a rubber O ring, and that is also probably a good idea, and may actually be better than my copper shim, if you can be sure it won't move once inserted. There are probably other ways to attack this problem as well, for instance you could mill the groove deeper that the throttle cable fits in at the leading edge of the throttle grip itself to create a reverse progressive pitch throttle grip to counteract the progressive pitch on the pulley.
Sometimes I wonder if someone at the vendor that builds the throttle plates didn't read the blue prints wrong and make the pitch on the throttle pulley exactly opposite of what was intended. I could understand making the throttle plates open faster at high throttle angles, but I don't understand doing it at low throttle angles where you need fine controllability and I am also surprised Yamaha didn't discover this in testing of the bike and correct it.
It's not a problem, it just a coincidence that this post to this point has over 1500 views.
