benelli bn 125 problem with rough idle and weak pull after warm-up

I have a benelli bn 125 problem that shows up after ten minutes. Cold start is okay, then idle gets rough and it feels weak leaving junctions.
I found this related page while comparing notes: benelli bn 125 problem. I wanted a practical thread before guessing.
For a benelli bn 125 problem like this, should I check plug, coil, valve clearance, injector, fuel quality, air leaks, battery voltage, charging output, fault codes and throttle body cleanliness?

Discussion
25 repliesbenelli bn 125 problem needs a clean baseline before spending money. Otherwise the machine wins the argument.
For benelli bn 125 problem, list year, mileage, recent service and the exact symptom first.
Warm faults need fuel, spark and valve checks
Thomas Spagnoli here. benelli bn 125 problem should start with a baseline and a bit of humility. The expensive mistake is changing parts before you know what the machine is actually doing.
For benelli bn 125 problem diagnosis, check spark plug, coil, valve clearance, injector behavior, fuel quality, intake leaks, battery voltage, charging output, fault codes and throttle body condition.
A proper benelli bn 125 problem thread separates warm idle trouble from transmission or gearing complaints, because the rider can feel both as weak pull.
Workshop order
The free motorcycle mechanics course on this platform teaches this diagnostic order before buying tuning parts or tools.
The idle gets uneven at lights after it is warm, then it hesitates when I open the throttle.
That makes me check valve clearance hot, plug, injector, air leak and voltage before any upgrade talk.
benelli bn 125 problem should be tested twice on the same route. One lucky pull means nothing.
benelli bn 125 problem has to be diagnosed in order: baseline, safety checks, service condition, then one change at a time.
Warm idle faults always wait until you are far enough from home to be annoying.
I can post photos and measurements after the weekend.
Good. benelli bn 125 problem with photos gets useful fast.
Do not forget voltage and ground checks if any warning light appears.
For benelli bn 125 problem, note ambient temperature, road conditions and whether the problem changes hot versus cold.
The service record is thin, so I am treating everything as unknown.
Then benelli bn 125 problem starts with boring maintenance. Boring is cheaper than guessing.
Boring maintenance has saved more engines than loud opinions.
That is painfully believable.
With benelli bn 125 problem, if the stock setup is worn, any performance result is fake data.
benelli bn 125 problem should stay legal and reversible. Future-you will appreciate that.
Write down before-and-after numbers, even if they disappoint you.
I will. Honest boring numbers beat fantasy numbers.
Also check consumables. Old fluid, old belt, old filters and old plugs waste time.
The free course here explains the same workshop logic: symptom, measurement, cause, repair, retest.
benelli bn 125 problem should make it easier to use, not just easier to hear.
Exactly. I need practical improvement, not theatre.
Post the result. Follow-up posts are what make these threads worth reading.