setting float height on '78 650 C2

Just curious, do I have to change my float height if I go to smaller jets ? I'm now living 2300ft higher than I was last year.
4 into 1
modified air box with K&N
dynaS and dyna coils
mildly ported head

Ran 110 mains with 17.5 pilots last year, seemed to work OK. Thanks in advance:)

Would not necessarily rejet moving up 2300 ft. Just give your old set up a try unless you were too rich to begin with. You certainly won't need to change the fuel level in your bowls.

I had what seemed like a lean condition last fall when I was riding. My bike would run Ok until I wacked the throttle to 8grand, then It would fall on Its face and I would have to baby it . I figured my jetting was out a bit so went to 100 mains and moved the needle up one notch. I may just have to remove the carbs and clean them as this has not been done for a few years.:ohmy:

Mac

The 110 mains should have been plenty big enough with your set up where it should not be falling flat at 8K rpms. I would carefully check ignition timing keeping in mind that the stock marks often produce incorrect results... in other words you might want to use a degree wheel and note if your timing marks are actually correct. Next, you might want to look at your ignition system. Check the voltage at the coils when you turn the key on. You may be underpowering your coils and getting less spark than you should with the Dyna stuff. I had a high performance Vulcan 1500A that would fall flat on its face towards the top of its rpm range and it was a weak stock ignition... the symptoms you describe are similar it brought the Vulcan to my mind. I cured the problem with a Dyna 2000. Last, if your bike does fall on its face at 8K rpm, I don't know where you bought your main jets. Are they genuine Mikuni? It wouldn't hurt to try some #115s to see if perhaps it is the main jets. Some aftermarket jets are just not as accurately drilled and formed as the Mikuni jets... most of the problems I have encountered have been with aftermarket pilot jets but who knows? I don't look in on the forums as much as I would like and if you would like to follow up, see my carb forum on my web site as I do look in there several times a day.

Thanks for you input WiredGeorge'

I do believe i have a fuel delivery problem,I removed the inline fuel filter and things got a bit better, more rideable, still seems like Its running out of fuel.
I set my floats dry @ 26mm, they were all set @ 22mm to begin with:ohmy: . I think I need to make a service fuel height tool!

I checked my coils, load tested my battery, wiring seems OK. Thanks in advance
Mac