Long Crank on 2003 Mazda Mazda6

Just bought me a Mazda 6 -03
Sometimes, about every 5th time I start the car it needs some extra long cranking before it starts.
I thought cleaning the MAF-sensor would fix the problem but no..
According to the service manual, the spark plugs where replaced recently.
Anyone who can give any suggestions on what the cause could be?

1 answer
Sounds like you have a starter problem, if the starter is good it could be the Teeth on the flywheel