2024 F250 engine issue after 20 hours

[Grady Pike]

I have a 2024 Yamaha F250, purchased new, and after 19.8 hours it has characteristics of one of the cylinders not working. I took it into a dealer (Seamasters in Dartmouth, Nova Scotia) to have it's 20 hour oil change at 16.8 hours. After this, the motor worked for one outing of approximately 3 hours, then the next time, at 19.8 hours, it seems that the motor is running on five cylinders. The dealer that performed the oil change mentioned that there's a 90% chance it's the spark plugs and that would not be under warranty. I find this hard to believe since I usually open up the motor before docking and shutting it off. Anyone else have issues with a new Yamaha F250 like this?

 

[boscoe]

What is the characteristic that you are seeing/smelling/hearing/feeling?

If it is believed to be a plug that is not sparking, find which one. Verify that the other plugs are working. Then swap the bad plug with a good plug and verify that the bad plug moves to its new position. Ruling out an ignition coil for instance.

While spark plugs are not covered by the warranty my guess is that if a plug is proved to be defective on a new motor that Yamaha Canada might provide a new one on a good will basis.

Read the warranty in your owner's manual. See snippets below.