[potboiler]

Now that the warmer weather is here in the UK my 2008 AVL Machismo is running just great. It doesn't pop on the overrun like it did in the winter. I guess the air is a bit thinner, making the mixture just right. The pilot screw is out to max. I am a very gentle rider of all motorcycles by nature and I ride this Enfield very slowly. However, my fuel usage has dropped considerably of late. During the winter I was getting 85mpg (UK gallon). Now I am getting  103 mpg UK, that's 86mpg US gallon or 36km/Litre.
Now, I know that these are called 'lean-burn' engines but I have never owned such a low consumption bike. Am I damaging the engine because perhaps the mixture is too weak? I have an after-market free flowing exhaust fitted with the PAV removed but I don't know if the jetting was changed by the previous owner. I also have an Enfield wind shield and a 72 litre wicker basket and only run 19PSI rear and 17 PSI front air pressures. I only do trips of 15 - 20 miles at a time along hilly and winding country roads. It would be interesting to know what could be achieved on a long journey on a freeway!     

[ace.cafe]

The slow riding will help the fuel economy, so that may play into what you are seeing.

[High On Octane]

If you were running ok in the winter months, you should be fine now.  The fuel mixture will get richer as the air temperature rises.  I did a complete retune on my bike over the winter months and got it running very good with just a bit of a cackle.  Now with the temps back in the 70's, the bike is running very strong with a nice rich-pop on decel.  FWIW  I also run my bike on the rich side because I'm an agressive rider with a heavy hand, keeping the tuning rich helps eliminate any detonation problems.

One thing that you might want to look at a bit closer is the fact that your pilot screw is turned all the way turned out.  Typically, you don't want that screw turned all the way in or out, usually only a couple of turns.  You may need to change your pilot jet.

Scottie J