ok you need to check the carbs all out first. You just go down the list checking things out. I think you can get to the screws on the carbs with the flame areastor on. It is easier without it there to adjust them. You can make a pop-up tester if you don't want to buy one. I am pretty sure the instructions are here on the site. Most of the time bogging is a fuel realated issue. If you RAVEs are all good it has to be a fuel issue.
Adjust the screws and do the carb syncing. Then check you pop off to make sure you are in spec. I have moved the srews by accident myself pully and putting back on the carbs and not checking the screws after I mounted them and burned a hole in piston. I would make the screws all little richer just to see if the performance gets better or worse. Richer is safer. Plugs are always cheaper than engines.
