2027 update: Okay. Pay attention. I am emphasizing this now because most of you aren't taking this seriously. Shipping is probably the most important step in submitting your carburetors to a carb rebuilder. That and good communication. Do not use USPS. Not only is the expense sometimes double that of the privates, but unlike the privates USPS will not, whatever they say, take responsibility when things go wrong. This is even more true when the shipment is international. I shake my head each time I get a USPS carburetor shipment. It is foolish. On the other hand, if your location is so remote that USPS is your only practical option, then it is what it is. Try to avoid it however.

International carb rebuilds
I no longer do international carb rebuilds. Regretfully. The situation with international shipping has become completely untenable. USPS International used to work. But, always a bit sketchy, it's now incredibly, stupidly bad. Even dismal. And it can be even worse incoming, because your country's state mailing service likely links up with my nation's excruciatingly embarrasing, inadequate state service and that is a disaster. As for the privates such as FedEx, well, International FedEx is nearly as expensive as DHL, and worse, requires I make two visits to the FedEx office for every international shipment. Until they fix this, I will avoid doing carburetors internationally.

International sale of how-to books
In the beginning I shipped how-to booklets sold outside the U.S. by USPS Priority International, because it represented the best that could be expected of our dear old Post Office. However, in response to complaints about Priority International's high cost, booklets have been going out USPS International Ground rate for several years now. It can take two weeks. As for Priority International, I don't know why a 6 oz. booklet should cost to ship more than the booklet's worth, especially when both International and Ground are actually air shipments, but it does. And let's not talk about Covid. The Post Office cost me a lot of money they never owned up to back then. These days, while USPS continues to prove barely up to the task, at least booklets appear to still be within their capability, both domestically and internationally. And worth the risk (I still have to replace lost international shipments every now and then--I'm on the verge of quitting that too). At least for now.

And please be explicit when giving me your international shipping address. If offshore, I need to know that because USPS reserves semi-secret, higher rates for stateside offsore, i.e., places such as Catalina, Martha's Vineyard, and other unusual locales. Also, don't assume I know where in this vast geographical world you are. Remember you are dealing with a very un-cosmopolitan American. Don't assume I am familiar with the details of your location. USPS is extremely particular, to the point that they frequently reject non-US addresses. Make it plain the parts of your address that are the city and state (or province), especially. Don't assume I know.

Boxing
About every tenth carburetor shipment I receive has the carbs poking through the box, and many boxes, while undamaged, arrive only by a miracle--tape loose, cardboard old and decaying, and little to no stuffing. Take a care. Your box should be at least two inches larger than your carburetors in every direction. Reinforce the inside bottom and sides of the box with extra pieces of cardboard (or double-box), cardboard wrap delicate areas such as throttle cable brackets and float bowl overflow nipples, and fill the space around the carbs with crumpled newspaper--after winding bubble-wrap longitudally around your carbs and placing them in the box. Do not use metal or plastic or wood boxes, not even totes. Every season I seem to get at least one. It's counterintuitive. Unless they are large enough to allow the necessary padding around the carburetors, your carbs are just as likely to get banged up in a metal toolbox as in anything else, and probably more. A word to the wise. And realize that most cardboard boxes get enough wear in travel that they become unreliable to reuse for return shipping. I almost always use new boxes when shipping back to the customer.

Bubble wrap
Use the large bubble. Small bubble wrap is for very lightweight objects. Most people use bubble wrap incorrectly. It should be wrapped around the carburetors, not stuffed between them and the inside of the shipping box. Use it for what it was intended for and works best for. Bubble wrap is way too expensive to use as stuffing.

Stuffing
The best stuffing is crumpled stiff paper, available at shipping supply stores. However, somewhat thick handfulls of newspaper properly wadded crumpled works nearly as well. Wad it and jam it. When you can shake the closed-up box left to right and up and down and not feel or hear thumping, you've stuffed it correctly.

Styrofoam
Myself, and others in my business, dislike finding styrofoam--especially peanuts--inside the box. The stuff is difficult to get out of my workshop and even out of my driveway--not to mention my neighbors' trees. More importantly, peanuts aren't designed to support irregularly shaped heavy items such as carburetors. Avoid using it please. I did once get a shipment packed with real peanuts. That was interesting, though I don't think it was any better a method.

Insurance
UPS and FedEx both offer $100 of insurance at no extra charge. You can and should add to that. But with FedEx, if you exceed $499, this will make the shipment automatically signature-required. I don't mind, really, but you might when your carrier tells you your carbs were undeliverable because I was away from the shop for a moment. So use signature required advisedly.

Checklist
Please always include the shipping checklist. It's foundational for the good communication that doing your project requires. Print legibly. It can be difficult to tell the correct return shipping address when it is hurriedly written.

Disassembled carburetors
I sometimes receive carbs in pieces. I don't mind. However, this virtually always results in missing parts, and frequently in damaged parts. Just this last week a loose float was thrown into the shipped box and arrived in four pieces. Never ship carburetors without the float bowls attached so that their interior parts are protectec.

Taping
Properly taping shipping boxes is important. Watch out for boxes that have absorbed oil or moisture, as this will make the tape come loose. Nor is tape a substitute for poor packing inside the box. And even the bargain store brand of box tape used intelligently is better than fancy tape incorrectly used.

Carburetor return shipments
All carburetors are returned to you using FedEx. Large, heavy, expensive boxes is their forte. I almost never use UPS and I never use the Post Office (USPS). This is the last time I will say it, but it bears repeating: You really don't want to trust your carburetors to USPS. Make sure your preferred ship-to address is legible on the shipping checklist.

ebooks
Like you I would prefer to do business as much electronically as possible. Of course I'm talking about my how-to booklets now. I get asked fairly regularly why I don't sell my how-to books in an electronic format. I'd love to! But it just isn't possible. I explain this in more detail at this link. Thank you for your understanding.

Let's recap:

1. Avoid USPS. The worst value and the worst service, no argument.

2. Box your carburetors correctly. If the box isn't at least two inches larger than the carburetors in all directions, it's too small.

3. Don't forget the Motorcycle Project shipping checklist. It is how you and I ensure good communication, a vitally important part of the project.

4. Styrofoam of any kind is anathema. Shop owners hate it, and the carbs are not at all protected by it. All around it's a bad choice. Use bubble wrap and crumpled newspaper instead.

5. Bubble wrap is meant to be used as wrap, not stuffing, which is the crumpled paper's purpose.

6. Never ship carburetors with the float bowls removed.

7. Take taping seriously. One swipe around the longitudinal seams is not enough. All edges should be taped, in both the X and Y axes, and extra taping around the box's circumference is advisable.