Sticking throttle at carb

[Iiwabucks]

Hey everyone, this is my first post here. I am fairly mechanically inclined as I have worked on muscle cars as a kid, currently have a Pro Street 79 Camaro Z28 roller that I am trying to get on the road but am currently suffering from lack of motivation on that project.

I have a friend in bad health with an 80 Yamaha 400 Special he wants to get running to sell it. Has less than 5000 miles but hasn't been started in a few years.

I changed plugs, air filters, changed oil/filter, emptied tank and filled with Seafoam. Drained Seafoam from carbs and going to empty that in the morning.

But my only problem I see right now is the throttle does not move at all. I can see it pulling at the carb, but the carb shaft does not turn at all.

This is the first time I have worked on a motorcycle, not too sure of the carbs anatomy to understand why it's not moving.

Anyone have any ideas where I should start looking?

 

[Iiwabucks]

After taking it apart I found that every piece is froze solid. Butterfly shaft won't budge, floats won't move at all and one slide was completely frozen. Havent even looked at the needle and seat yet.

 

[JohnP]

I would order a set of carb kits and do a rebuild. In the mean time Soak them in a bucket of solvent of some sort. I have picked up several guns over the years that were completely seized up because the owner thought coating them in oil would preserve them. Some "oils" will harden over time. For guns I have used mineral spirits for carbs i stick to carb or throttle body cleaner but don't remember seeing outside of aerosol.

 

[CaptChrome]

You will probably find it all is stuck with varnish or corrosion. Try soaking the carbs in some carb dip or injector cleaner. This stuff will destroy the rubber parts in the carbs, but they might start to move. Getting rebuild rubber and seals is pretty straightforward, unsticking carbs without using too much force is risky.