Top Speed 60mph on Highway.... Then It Stalls!

[BigD_83]

I appreciate all of the input guys. I don't know if I'm comfortable jumping right into multiple repair tasks myself with no experience. I don't mind learning starting with maintenance, but I'd rather have a shop do any intricate repairs (valve adjustments, carb rebuilds, etc...) at the beginning here.

Symptoms after an afternoon of riding:
- Takes a long time to go 0-60
- Tops out at 60mph in 5th and then slows down until it dies. Starts back up with choke
- Bogs down immediately after shifting into 1st and 2nd gears, probably wouldn't do a burnout if I had the throttle wide open when shifting into 1st
- I filled the tank up the other day with premium (mechanic's advice) and after 38 miles, I'm down to a 1/2 tank already
- It also smells strongly of gas when idling, though it doesn't drip gas onto the ground when shut off

I definitely need to buy a brand new petcock, right? What else should I go ahead and and get brand new for the mechanic?

One other question: Is a VERY slight clunking sound/feeling normal when shifting from neutral to 1st, before letting the clutch out? Does this mean my clutch needs adjusted?

The nice thing is that you don't have to do all of the repairs at once. You can really only serially monotask. Prioritize, and work your way through the list.

A valve adjustment is actually a very simple task, and shouldn't cost much more than an extra shim or two and a new gasket to do it yourself. This is one task that a "shop" will charge hundreds of dollars that you can spend on fixing other problems.

It does sound like you've made a great start by finding the airbox issue. Now get out there, sort the rest, and ride.