Maytag Dependable Care Quiet Plus - Dryer won't get hot enough

I received this gas dryer from a friend, converted it to propane.

My only issue is that it takes extremely long to dry the cloths. I hear the burner come on but does not seem to run long. Temp inside the dryer is warm but not hot. I cleaned out the exhaust duct work and am getting good flow or at least the same as I had on my old Kenmore dryer.

The dryer runs through the cycles no problem, just takes forever to dry towels etc..

Could their be a temp control sensor or something not letting it heat up fully?

Any help appreciated