If it has a carburetor, then yes, it should be a simple adjustment. No specialized service center, or factory trained technician needed. Any qualified mechanic would likely have it fixed in moments. You can easily do it yourself if you're careful.
The idle itself can be tuned on some equipment, on others, an adjustment to the air/fuel mix would be the fix. It's the fuel injected, CPU controlled vehicles that are more complex, and require more extensive knowledge, and tools.