This looks like a good deal for the right person Josh
The main problem for new owner will be getting passed Central American borders with a title that is not is his name, with an import permit in your name.
Is this bike registered in a USA state? (small detail you left out!) If it's a foreign based bike, it can NEVER be registered in the USA, but someone can enter as a tourist on it.
Every Central American country is a bit different, some may not allow the new owner to cross with unmatching paperwork or will not issue an import permit for the bike without going through major bribery ... who knows on this ??? I would never try it myself ... too many headaches.
The thing you CAN do is meet someone in Mexico, hopefully just over the Mex/Guat. border, and hand the bike/title over. At this point you will have your Mex. import permit for the bike. Go to a Notaria (Notary Public) and get a sworn, stamped, statement with your Passport (copy) and the new owner's Passport, stating you give permiso for new owner to ride the bike to the USA. Include all bike info. (license, VIN, import permit number, et al)
You should NEVER, EVER mention the word SALE. Just say you've had to leave Mexico due to an emergency and your "good friend" is helping you out. (Parent died, sick, your sick, what ever).
If you say SALE ... you will be dead in the water!! You cannot Sell anything in Mexico .... to anyone without paying massive tax and doing lots of paperwork. (same with Central America, far as I know)
The Notary will translate into Spanish, stamp/sign the letter, you and new owner will sign it as well. Hopeful this should get the new owner through Mexico. They rarely check papers but they DO check from time to time.
Getting into the USA is NO PROBLEM at all regards the bike. They don't care anything about registration/ownership/insurance at the border. As long as the new owner has the title or registration, some sort of US based insurance and so long as the bike is not reported stolen, then the new owner will get into the USA no problem. A foreign traveler will need a USA Visa of course, but a US citizen only needs a Passport and probably won't be asked for it.
At that point the new owner would have to go to the DMV in his home state and transfer the bike into his name. Done.