I am trying to power a Maytag centennial dryer using a Wen 5500 generator.
It seems the dryer pulls too much power and trips the breaker on the generator after a couple minutes.
I have been told I can wire the heating element to run off 120 volts and it would reduce the power draw by 50 or 75 percent.
Could a use a diode to reduce the power draw slightly? I think the 5500watts from the generator is almost enough.
I looked into getting a lower wattage heating element, but I don't think any I found would be a direct fit for my dryer.

 

Doesn’t it have a control for how much heat is used? Mine has “air dry” plus 3 levels of heat.

 

This is allegedly your wiring diagram. Can you confirm it?

Based on this, it appears the heater element is single element - like a lightbulb - and there's no indication that it can be wired differently.

 

I have been told I can wire the heating element to run off 120 volts and it would reduce the power draw by 50 or 75 percent.

That would reduce the power to 1/4 since power is proportional to the square of the voltage, so that may be too much.
From wayneh's diagram that might be possible by moving wire BU 28 from L2 to N.

Could a use a diode to reduce the power draw slightly?

No.
A diode in series would cause a large DC component to the AC current, which could damage your generator.

I looked into getting a lower wattage heating element, but I don't think any I found would be a direct fit for my dryer.

Could you possibly add another element and place them in series?
That would cut the power in half.

 

Doesn’t it have a control for how much heat is used? Mine has “air dry” plus 3 levels of heat.

The dryer reduces the heat by cycling the heater, not reducing its power.

 

It doesn't say on the generator spec whether it is petrol or diesel. I'll guess at petrol, so it will be about 20% efficient.
If you connect the heating element to 120V it will reduce its power to 1375W.
If the generator is producing 1375W of electricity, it will also be producing 5500W of hot air, so you could duct that into the dryer (if you can avoid the exhaust gases) to make up for the lack of power in the heating element.
CHP in action!
Oddly enough,I am familiar with the Maytag dryer, as my wife brought one with her when she moved here from the USA, and I had to figure out how to wire it up to a British 230V supply. It needed a separate 32A supply from the fuse box, and a 120V transformer to run the motor. I'd never seen a tumble dryer so big!