It just amazes me how two people, both very successful, Steve being more successful than me, can be so different with their carb settings.
The only point we agree on is the height of the fulcrum arm. For Enduro racing that is, that's where I always put my fulcrum arm, regardless of the type of racing. It always intrigues me when people talk about Popoff pressure. You need some, 10 pounds is some, I've never seen any difference with anything else. Needle settings?? We always set the high at about a quarter and the low-speed about 2- 2 1/2. We used the EGT, so I absolutely know that those settings were the best for us. Even those settings need adjusting with changes in the air density. On a real low air density day, we have run with the high-speed closed. Or very near closed. Oh, I should mention, this is with a pipe. Still, with a muffler they don't change a lot. We have gone from a pipe to a muffler, and after readjusting the clutch, I can't say that there was much change in the carburetor settings. Nothing major, the driver may have done some minor adjusting.
Tuning with a CHT is a waste of time in my opinion. The EGT tells you what's going on inside the engine. The EGT responds much quicker when tuning. The great thing about the EGT, if the engine starts to detonate a little, even a little, the EGT will go down. It gets a little tricky, because the EGT will go down if you're too rich also. But, if it goes down, the first thing you do is richen the engine up a little, if it goes down further, go the other way. It's totally different from a CHT. And much more precise.