I can't find any good pictures of the heat shield which goes above the valve cover under the air box. I made my own from an old piece of rubber and it drastically changed the way the thing ran. Just wondering if I did it right. Do the stock ones completely seal off the otherwise open areas between the bottoms of the frame rails and the engine? Or is there space for air to enter? Thanks in advance, heres one of the only pics I could find of one

 

your welcome.... look on ebay there are a few on there for cheap...

 

As far as the seal, it's definitely not air-tight, and of course, if it was a completely sealed area, you wouldn't have any air to feed the engine!

When it's the right shape/size, and positioned correctly it mostly seals off the intake area, and causes the air to be drawn in from the openings on either side of the pocket that's created... that's why those circular cutouts are present in the gussetting between the upper and lower frame members, jus behind the steering head.

As a heat shield, one might think that just a piece of rubber wouldn't be all that affective, but it does the job well enough. Running without one woud not be recommended, because in addition to channeling cooler air from either side of the bike, rather than drawing in very hot air from above the motor, it also prevents water and debris from entering your airbox snorkels, to some degree.

 

even know the F2 does not have ram air it does have a fresh air system known as air direct intake cooling system and the heat shield plays a part in this system as well as blocking heat and when in place it acts like a fresh air box where engine will intake from this reserve of fresh cool ((ambient temperature))air.. the theory is that the cooler the air entering the engine the more of a dense charge in the combustion chamber witch= more power...the system is feed by the 2 air ducts on the upper fairing so when the heat shield is in place the engine will get its intake air from...

 

The shield mostly creates a still air box for the intake snorkels to pull air from. Without the shield, the air will try to pressurize the airbox and mess up the fueling. Look at the stuff Honda did with the ram air F3s to get them to carburate evenly through the rev range. Air can "stall out" when it exceeds the capacity of the opening it goes into. Like trying to fill a milk bottle with a water hose on full. You'll notice when you stop, the bottle is never completely full, despite being force fed. Air is really thin water and engines are air pumps.

 

Yes thank you very much for initially alerting me of the shield's importance!! And thanks to the rest of you for the descriptions. I think what I made is almost identical to stock

 

good..let us know how you make out..