It was designed to protect bare metal parts from rusting. It wasn't designed specifically for use on carbs. Since it's a new product, people are still experimenting with it. To apply RPM you have to heat the part up to 120 degrees. When the product comes in contact with the heated part it melts. The area turns shiny so you can see where the product has been applied. Once it dries, it's invisable. If you put it on a little too thick, you can buff it to bring back the shine.
I think it would hold up nicely if exposed to fuel on a limited basis. Only time will tell. I've heard some people are going to try it on exhaust manifolds so they can be left bare metal also. It was never designed to see that much heat but maybe it will work there too.
I started using it on all the fasteners I refinished. I used it on my UCA came bolts, master cylinder, driveshaft exc...
