Problem has been solved and it was very simple.
I figured I'd start with a new fuel line, so off to the local Yamaha dealer, got a new fuel hose and went back to try it out. It didn't fit my tank. It had the wrong type of connector at the tank end.
Back to the dealer: "This hose doesn't work for me, wrong connector on the tank end."
Parts manager: "What kind of tanks do you have?"
"Yamaha tanks."
She took me around to look at all the hoses they had with connectors for Yamaha tanks: "Nope, nope, nope....come on out, I've got the old one in the truck."
Soon as she saw the old one, "Oh, those were recalled in 2014. Yamaha would provide replacements for your fuel pick up and give you a new fuel line as well."
We went back inside and she called Yamaha. They said give then the motor serial number and, even though long out of warranty, they would send replacement parts (they didn't have any in stock at the dealer. Only problem was, they were sending from Japan and it would currently be about 2 months. I don't want to wait two months. She went online and found that, regionally, there were three in stock, one in Savannah and two at a dealer in Columbia. Great, I have to go to Columbia Thursday anyway. She gave me the number of the dealer in Coumbia as well as the part number. I called, yep, they had them. Offered my CC number to hold for me until Thursday. "Just give me your name and I'll hold them for you."
Picked up the new fittings in Columbia yesterday. Refitted my tanks with them this morning, tried it out....runs like a champ. Will idle forever now.
Apparently, the old style, when they got a few years on them would get kind of aged and wouldn't seal well. That's why under throttle, there were no problems, the fuel pump was sucking hard enough to keep the connection tight enough that id didn't leak. Get down to an idle, and it would loosen up and start sucking air.
I like simple solutions....no carburetor, fuel pump, timing, spark plug, reed valve or other issues...just replace the old connectors with the new style.
Again, thanks all for thoughts and suggestions.
