So where to begin...
I didn't forget: with all the variation in the castings of the carb body & float bowl as well as the gasket & gasket compression, the marks are only a relative measure of fuel level so I can easily see the changes. The marks are adjusted so they actual read from the edge of the bowl down which removes casting variation in the depth of the bowl.
I tried to follow the Bing recommended method as well as Snowbum's lift the float method. Of the two I think Snowbum's is the better method. the thing that both of these methods depend on is floats of the same volume & buoyancy.
I just hate lying on my side trying to figure if some faint line on the float is level with the bottom surface of the carb body. I even used the float bowl bail to hold the float in position but to me it's just too inconsistent.
I'm running 'older' floats & they certainly are not the same volume. When set to the Snowbum method, there is a difference in the fuel level.
Yes, I have new floats on order... But if I can figure this out, I can make old floats work as well.
I also tried Snowbum's stick in the bowl with a notch & got tired of it.
When I read the marks, I place the bowl in the same place & in the same orientation to reduce variations from unlevel surfaces. Like I said, the marks aren't absolute but they do let me know how much I've changed the fuel level as I tweak the fuel level.
so the first thing I do is take two reference readings before I start playing with the level.
I really like the idea of a clear float bowl to see where the fuel level is wrt to the jet stock. This doesn't really have to mimic the bowl just its gasket profile. It could have scribe marks on its side for fuel level reference.
Some days it's fun to be a mech design eng ne aircraft mech ne logger. Give me a bit & I'll whip up a model.
Fuel level & performance...
The left carb is being a problem child. It was running lean though the needle & main jet. As I increased the fuel level by 1mm the needle jet came alive but the main is still way too lean 14s at the cross over, 17s at wot. Basically, the bike is running on the right cylinder.
One of the things that concerns me is that with the rake of the R65 carbs, the fuel level can get high enough that the idle ports are below the fuel level. I think I'm seeing this on the right side as the idle screw seems to have lost it's effectiveness.
Did I cover everyone's questions?
Here's a gotcha: When I got this bike a year ago, I had the shop lash the valves & check the timing. Well, in a fit of 'just in case' I thought I'd check the valve lash & timing.
Left exhaust was set to 0.012" but the rest were fine.
Can't find the timing mark with my timing light. The marks are there, I've repainted them with bright yellow nail polish but I can't see them. The mark I do see is ~60 away from the timing marks.
I'm wondering if the flywheel was put on one hole over the last time the clutch was done.
Anyone know if it's possible to install the flywheel one hole over?