Yamaha f80 carbs issue. Throttle won't advance

My f80 2003 ran fine last trip. Now throttle will not advance more than just past idle. The engine starts and runs fine. Disconnected cable and see that the issue is with carb lever, not the remote or cables. Seems like the connection that goes up to the 4 carbs simply won't budge. Disconnected the pushrods ball link between the two moving bellcranks and the front lever moves freely, the rear one that connects up to the carbs moves only a small bit. The arm protruding into the cutout in the middle of the lever should probably move around in this hole, but does not. Help appreciated. Henning

Update. I have isolated the problem to the spring loaded arm of the bottom carb. This hardly moves and I have to use a pair of pliers to do so. I believe this should move freely as the throttle lever is moved. The other three carb arms move freely. I disconnected the pushrod between all 4 to check. Any ideas? Regards Henning

Henning said:

Update. I have isolated the problem to the spring loaded arm of the bottom carb. This hardly moves and I have to use a pair of pliers to do so. I believe this should move freely as the throttle lever is moved. The other three carb arms move freely. I disconnected the pushrod between all 4 to check. Any ideas? Regards Henning

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Have you tried using a penetrating lube like PB Blaster? Spray that onto the lever and let sit for a few mins. Then try and move lever. It shouldn't just lock up like it is unless corrosion has hardened the articulating surface. If that doesn't work, get all the fuel out of the carbs completely, disconnect fuel hoses to carbs, and apply pin point heat. You can heat cycle using a non flammable lube like automatic transmission fluid. ATF then heat then move lever. Repeat.