Route from Guatemala City through Tikal and out through Cancun?

http://sweatypeten.blogspot.com/ A different route but I do not know if common carriers are running the route.

Imo that's enough time to really enjoy those places. You could avoid Belize by heading to Palenque among other routes. While Guatemala is our favorite, we love Belize, too - lots of cultural interest plus great caving and blue water options. My photos with blog, travelogue, and review links on the main page of each collection are below in case you're interested - all my recommendations are embedded there.
Happy trails!
http://www.flickr.com/photos/staceyholeman/collections

You may want some snorkeling time on Caye Caulker in Belize and some beach time in Tulum before you head toward Cancun. It is a fairly easy, well travelled route. Here is what I would do. You can get an overnight bus from Guatemala City to Flores or you can fly. I would spend the first night in Flores and then shuttle over to Tikal park and spend two nights there. The reason for two nights is that the ruins are best visited just before dawn until about 9:30AM and then again in the afternoon for sunset. After your second night at the park you can wake up early and catch a shuttle to meet the bus from Flores that will take you all the way across the border, into Belize and will drop you off at the Marine Terminal for Caye Caulker. It is a great trip and value for $25US. If you are hesitating about visiting Belize because of the expense just understand that on Caye Caulker you can find a decent room in the $30US range. Now when you are done on Caye Caulker there is a great boat ride from there all the way to Chetumal, Mexico for under $50US. You can catch the bus north and spend a night or two in Tulum for the beaches, cenotes and a great ruin at Coba. From Tulum you can catch a bus right to the airport usually the same day as an afternoon flight. This is how I would do it and I have been there many times. These transportation options are easy, peasy , inexpensive and will allow for a rest stop right when you are about ready for one. With a 4 week time frame it will largely depend on how you budget your time. I would skip the crowds at Chichen Itza since you will be visiting much more raw and interesting ruins anyway. Have a nice trip!

Thanks for your help! Hofulist you were saying that you don't think it's enough time? Are there reliable buses going from Flores to Palanque?

Imo = In my opinion that's enough time to really enjoy those places. :-) I know it is possible but I have never made the trip between Flores and Palenque; try a search here on the forum and if you can't find a recent thread, start a new 1.

I've done that trip multiple times, crossing from Guate to Mexico both via Belize and directly via the Usumacinta border or El Ceibo. Both are easily doable, and there are lots of tour operators who offer the trip to Palenque, crossing the border by motor boat on the Usumacinta at Bethel/Frontera Corozal. That's a rugged and very beautiful part of Maya land and lots of people make that trip every day, but I wouldn't advise trying to do it by yourself. Belize is very easy to travel through independently, and there are a few attractions that you might find worth slowing down to take in (ATM cave, Caracol, the cayes).

I agree that you can do this in a month.

As a final tip you should make sure to visit Coba and Ek Balam while you're in the vicinity of Chichen.

It's definitely enough time, I did antigua to caye caulker in 2 weeks ( https://tripstory-new.appspot.com/web/#/share/5076495651307520 ) - you will meet a lot of people taking the boat from caye caulker to mexico.

So you have around two weeks in Mexico - sounds like a great time. Enjoy :)

Yeah a month is good for that route.

Couple options for breaking up long bus/shuttle rides, Copan is an easy 5 hours from Antigua, cool town and ruins. Rio Dulce is another nice place between GC and Tikal, if you do take the jungle/canyon boat ride.

Highly recommend the ATV cave trip in San Ignacio. think you would enjoy 3-4 days on Caulker.

If you must do Chichen Itza, do it early out of Valladolid to avoid all the crowds.

Coba is a very nice site, rent some bikes and cruise around, plus you can still climb the Pyramids as opposed to Chic.

Yes a month is sufficient time to see both the Yucatan and Guatemala. I rather like to avoid Belice as they nickel and dime you to death there. Suggest you go and visit Tikal and then arrange to cross into Mexico from there. Have photos of my trip crossing from Mexico to Tikal on my website wolf calls.com. I loved the crossing of the rive from one country to another, If the border station is closed in Mexico when you arrive you can also check in at the one in Santo Domingo de Palenque. You then get to see Palenque which is fantastic. Photos on wolf calls.com. I much enjoyed the river passage between Guatemala and Guatemala.