Need more information.
New gas? Who cleaned the carb? No, not the name. Some booger picking kid with a paper clip? Real mechanic? Try running it on Prime. Or,does it still have the OEM petcock? How many miles on it?
Will it rev up in neutral?
Don't let it sit and idle on the kick stand. The engine can't get oil to the high end of the cam and it will mess it up.
Other than the carb,has there been any other work done? Do you know Why it got parked for so long?
Does it have a fuel filter between tank and carburetor?

Looks like the throttle cable is either adjusted short or the throttle just isn't closing. The plate the cable is attached to? See how far the idle adjust screw is from touching it? You are idling at almost quarter throttle.
I would pull the fuel line off the carburetor and see how fast fuel is being delivered to the carb.
Make sure the kid plugged off the vacuum line that the OEM petcock used.
If that fuel line is skinnier than what it calls for, you won't get good fuel delivery
Aaand
If the kid bought a cheap knockoff petcock instead of the Official Yamaha ,about thirty dollar petcock, it has skinny plumbing and will not deliver.

Why is the speedo disconnected?

Also noticed the gas line is too long. It's going upwards before getting to the carb. Should be going directly to the carb with preferably a fuel filter.

The petcock should have an 5/16" outlet! If it's 1/4" it's a knock off aftermarket. You can get by with it for now until you resolve the carburetor issues. But at full woot  it might starve the engine. ( think full throttle on highway)

justin_o_guy2 wrote on 09/03/22 at 13:38:15:



If you don't do the tests,you won't know what is going on.
Looks like you have a petcock that should be in the trash, maybe not.
You have to Prove fuel delivery to the carb.
Without that, it can be a new,perfect carb,and it's Not gonna run wurfacrap.
If he didn't plug the vacuum off,not gonna run wurfacrap.
If he didn't remove the shipping sleeves from the petcock.

Step One
Check fuel delivery to the carb.
Establish That.

If you establish that you have sufficient flow through the petcock and your fuel line to make the engine happy, connect the line to the carb and open the bowl drain and catch it in a measuring cup. Time it to a half cup.

verslagen1 wrote on 09/04/22 at 09:01:09:


I stand corrected! verslagen! 🙌
Sometimes my knowledge is skewed to my childhood of working on 25yr old heavily neglected mopeds with seriously rusted out tanks. The filter was the only way to keep them running for more than a day or two. Gas would go in clear but the petcock poured brown.  

Awesome, I appreciate all the advice. I have adjusted the throttle so it touches as it should. It was stuck. Do know the diaphragm is new and installed and seated as it should be. I saw that when I took it apart. As far as a worm or sticky slide I don’t know what that means or how to check it. Please go in-depth on this for me.
I want to get the right parts so this works as it should can anyone direct me to the correct or better petcock and where the cheapest place is to get it. Thanks.
Adjusting the throttle did help. I was able to hit third gear, but all gears  sputter at the top end. I am guessing( I don’t know) if that’s due to the wrong petcock and fuel supply. I hope this will solve the issue. Thanks for the help and please continue to help me out. This is my first bike and I enjoy working on it.
I have attached a pic of the other side of the carb. Something is capped off. Also the screw in the top right corner is way screwed in, should it be? How do I adjust that to proper setting? Should I have a filter between the petcock and the carb? I did not rebuild it. I took it apart to see how dirty the carb was. I was very clean so I hope whoever had it before me did not do anything but clean it.

14gills wrote on 09/04/22 at 20:23:23:


This is easy, if you twist the throttle and nothing happens or it suddenly happens it can be a stuck slide.
sometimes the slide will stick when moving it by hand too.  remove the rubber ducky between the carb and airbox, you can use your finger to lift the slide.  it should move up and down freely.  

You can add lucas fuel injector cleaner to your gas to help eliminate the problem.  About an ounce per tankful.