[retro]

I'm less than 300 ft above SL. I can't find anything but main jets and stock rebuild kits anywhere.

I'd put your carb back to stock jetting and try again. I'll wager it won't need much tuning from stock, if any.

 

[retro]

Is it an OEM original carb with 100% original jets and all other parts original in it? Your carb boots in good shape with no cracks in them? Did you take the snorkel off and try it with the OEM carb all stock? You need very little (if any, and probably none) jetting changes with your setup, so something is wrong with your baseline stock config. My guess... its not stock.

 

[retro]

Ya, check the float level while you are in there too. But if your new carb is not a genuine Honda carb of the same model# (is it an aftermarket carb? China?) then no, you'll have to reassemble your original Honda supplied carb to stock and use that.

 

[retro]

I would put everything back in the original carb and run it... set it up stock, exactly like the service manual says... got no idea what sort of carb you bought (china knockoff?) or what it was meant to fit or whether stock Honda jetting parts will even work in it. Why did you replace the original carb?

 

[retro]

Is it a brand new OEM carb? Was it the exact Honda part number for your year and model application? If parts are different in each, then obviously it is not. No way to fix that... gotta have the correct carb set up perfectly stock.