I have a Chicago electric generator 3500 watt that won't come up to speed

SOURCE: No power produced by All Power America 3500 Watt Generator

see if the breakers have been reset.

SOURCE: Older Coleman 3500 Watt generator, sitting for

there can be many reasons. need more info:
Is it Inverter typr generator?

measure output voltage - anything?
take back cover off generator itself, measure continuity of stator and rotor, and visually inspect windings. You'll find AVR module there too, it may be the reason.

SOURCE: I have a Nikota electric generator 3500 watt 6.5

I also have a NIkota 3500 generator, which had a carberator problem. I just ordered a new carb from Yilong-motor.com in China. They may be able to help you. RJL

SOURCE: How do I connect 2 1850 watt coleman generators

It wont work. Electricity does not work like that. you can't double the power just by doubling the watts or amps. there is a lot and lots of other things involved.
I would rewire you camper so that half is run be one generator and the other half by the other generator... SO lights and fridge on one and plugs and heater on the other maybe...

SOURCE: i have a problem with

did you blow out old gas from gas line going to carb? if this generator set up over the winter with no use, it probably has water condensation in the gas tank which has gotten into the gas line and carb. If you didnt do it already, blow undo the gas line off the tank and use compressed air (or by mouth) to blow out all the fule out of the line and carb. If you did not drain the old gas out before adding new gas, there still may be water in the tank and line. Try this and see if it fixes it. Give it time for the new gas to get through the line to the carb. To avoid this, keep the fuel tank full especially over the winter and you will not get any water condensation.