starts idles fine can't rev over 3500

So the Screens above the Float Valve are clean? # 14043
Make sure the # and the small holes in the side of the emulsion tube #16017 are clean.



The slides have a reference notch for the Diaphragm, and a vacuum hole that faces the engine side, make sure that is correct as the diaphragms could have been replaced. Also I would compare slide springs between carbs, 1000 & 1100. Someone could have swapped in something else, check the needles, make sure the assy looks like the picture for the retainer for the needle. Its pretty easy to test the Diaphragms for leaks. Take your thumb and forefinger. Thumb over the vent port in the air horn, and finger under the slide. Lift the slide with your thumb off, and when the slide is up, cover the vent completely with your thumb removing your finger. Slide should hold at the up position.
The Fuel Level is of course critical, dry height is a starting point for set up on the bench. If the heads are getting bad on the drain screws, you may need to replace them, but I would use the 1000 bowls as they are the same. Set the Fuel level with them, so the carb gets the correct signal through the fuel jets.

Start engine, rev until it start missing, lay your arm across the back of the carbs, restricting the air flow, as you lay your arm across it...if it revs up, you are not getting enough fuel, if it gets worse and cant see any improvement no matter how you lay your arm across them, you're too rich.
You MUST follow the symptoms to find the problem.

Thanks for all the input and ideas.

Motor Head wrote: So the Screens above the Float Valve are clean? # 14043
Make sure the # and the small holes in the side of the emulsion tube #16017 are clean.

I blew thru the fuel inlet hose and felt like all float valve screens were clean, but will visually inspect. Never pulled and checked the emulsion tubes except as I mentioned they all seemed loose in there bore.

The slides have a reference notch for the Diaphragm, and a vacuum hole that faces the engine side, make sure that is correct as the diaphragms could have been replaced.

Already mentioned, were wrong corrected, no difference.

Also I would compare slide springs between carbs, 1000 & 1100. Someone could have swapped in something else, check the needles, make sure the assy looks like the picture for the retainer for the needle. Its pretty easy to test the Diaphragms for leaks. Take your thumb and forefinger. Thumb over the vent port in the air horn, and finger under the slide. Lift the slide with your thumb off, and when the slide is up, cover the vent completely with your thumb removing your finger. Slide should hold at the up position.

I'm not exactly sure where the hole in the air horn is your describing. What about the hole in the bottom of the slide? I thought that was were the diaphragm got it's vacuum? Thus the reason for drilling it out larger to get more vacuum for quicker slide/throttle response?

The Fuel Level is of course critical, dry height is a starting point for set up on the bench. If the heads are getting bad on the drain screws, you may need to replace them, but I would use the 1000 bowls as they are the same. Set the Fuel level with them, so the carb gets the correct signal through the fuel jets.

I was able to get drain screws out and all levels are a tad high 1/8 to 3/16 from top of bowl.

OldSchoolZ wrote: Start engine, rev until it start missing, lay your arm across the back of the carbs, restricting the air flow, as you lay your arm across it...if it revs up, you are not getting enough fuel, if it gets worse and cant see any improvement no matter how you lay your arm across them, you're too rich.

I tried a version of this by using a folded towel and the results were mixed. While revving (not holding at max rpm of 3500) It revved to maybe 4k then acted choked out and died???
Per motor head's idea I'm going to pull the float needle screens and emulsion tubes and inspect and see what I find.
Thanks again guys I'll keep at it. Just hope I can nail it down and not waste all this time and end up having to get different carbs

"I'm not exactly sure where the hole in the air horn is your describing. What about the hole in the bottom of the slide? I thought that was were the diaphragm got it's vacuum? Thus the reason for drilling it out larger to get more vacuum for quicker slide/throttle response?"

If you look at the diagram i posted, you will see the odd shaped large port/ hole at the top of the Air Horn/ Bellmouth Intake side of the carb. If you lift the slide up you will feel the air escaping here. So all you need to do, is like I said, place your thumb over it when the slide is up. if the diaphragm, or lid is leaking, the slid will go back down. As it should hold. Also you could do it with the carb inverted in a pan of liquid, and see if it is the lid that leaks, if you have one drop down.