Check the roller bearings of the main plunger. Ensure they are free of debris.
Regulate your ground speed using your tractor's transmission gears, not the throttle. Gallignani 3690 Manual
To get the most out of your manual, follow these tips: Check the roller bearings of the main plunger
Specialized forums such as The Combine Forum or TractorByNet are excellent for user-shared manuals or advice. 5. Summary Gallignani 3690 Manual