^^^ I think he just got lucky the first time. with that compressor set up he might get 2 maybe 3 passes on that tank and be OUT of air. that's one pass down each side an then the top, were normally you would need around 8 passes. as soon as he pulls the trigger his pressure an cfm are going to drop drastically on that 8 gal tank and the compressor just cant put it back. he needs to get information on the products he is using and try and spray a little closer 6-8 in.
Jay D.

Even a broken clock gives the right time twice a day.

did you clean your gun properly?

I'm far from a pro, but I'd go with the compressor/volume supply. I was seeing the same type of conditions and was perplexed because the day before I was laying product down great and used the same setup. Well, I forgot to plug my compressor back in I got to see first hand what happens when you loose the volume needs of the gun.

So anything I could do besides buy a giant compressor? Maybe get a gun that requires less cfm

Or what do you guys think about using spray can clear coat and then sanding and buffing it?

If you want to do this as some sort of side gig more than just this one time, then yes, buy a larger compressor. Always get more CFM than the gun says it requires, so the compressor is not running non stop, which creates lots of heat, which in turn creates lots of moisture.
If this is a one time deal, try again, maybe get lucky a second time with what you have. I'd shy away from anything rattle can as it will only be single component.
One last option, if your interested in rattle can, usually your local parts dealer or paint supply dealer, Oreilly or Advanced Auto even, can mix your clear and activator, then push it into a rattle can for you. Looking about $20 per can, but might just get you thru this. Don't expect show car results with that crappy 3 cent spray nozzle, but it would sure be better than off the shelf rattle can clear.
If you wanna look at painting/auto body as a side gig, then read, read, and read some more on this forum. It's all on here someplace, just find the info and absorb it and get ready to spend to buy all the right equipment, tools, and materials to do this gig.

Maybe do a few tests to see if air is indeed your problem.

First, do you have a pressure gauge/regulator attached to the gun? If not, get one. A cheapy from Harbor Freight will work. Second, use a good short hose. 1/4" will not do it, 50' of 3/8" might, 25' of 3/8" would be better.

Adjust the regulator on you compressor for 50 PSI or so. Load the gun with water and adjust the pressure at the gun with the trigger pulled for what you would want if spraying clear... let's say 30PSI. Let the compressor fill up, then pull the trigger and watch the dial to see how long it takes for the pressure at the gun to start dropping below 30PSI. Then let go and see how long it takes for the compressor to catch up. If the compressor can only run the gun for 30 seconds or less it's going to be tough to get a good finish. If it's 30 second or more you can make it happen, but you might have to make a couple of passes then wait for the compressor to catch up. How long did it take for your compressor to recharge? If you can run at 30 PSI for a full minute or better you should be good for motorcycle parts or panel painting.

I have sprayed a lot of small things with an elcheapo 3gal. pancake compressor and a 6cfm Harbor Freight detail gun. Just have to make a few passes and then wait for the air to pump back up. I am currently using a 15gal. DeWalt compressor. It can run a 14CFM gun continuously for better than a minute before pressure at the gun drops. I recently sprayed epoxy primer on a full set of 9 motorcycle parts with no problem what so ever. Compressor wasn't even working hard.

Point being, you don't need a huge compressor to paint a motorcycle tank.

They do and 2 part clear available in aerosol cans from your local jobber. The hardener is sealed in a chamber inside the can. You push a button on the bottom of the can and it breaks the seal between the two and you shake to mix. I have no experience with this stuff tho.