AR240 engine cranking but not starting

[aturlik]

I have an AR240 with an engine that will crank but not starting. Have called the dealer for some mechanical tips and things to look for. Have changed the spark plugs, cleaned out the clean out port, have checked the land yard connection, cleaned all the connections to the battery and starter. Has anyone had this issue?

 

[Babin Farms]

Are you getting spark and fuel?

 

[aturlik]

The engine will crank but not start.
Spark plugs have been changed and the battery has been checked.

 

[Bizywk]

Let's clarify - We're assuming you have one engine working fine and the other turns but won't start - correct? We're also assuming that the engine that isn't starting is cranking without laboring at approximately the same speed based on sound - correct? You mentioned that there are new spark plugs. Did this problem arise before or immediately after you serviced? Did you verify that they were Yamaha factory recommended spark plugs? Is there anything else that may have happened to it recently or did it just suddenly fail to start recently?

If it's just one engine that is giving your trouble, most of the basics such as your lanyard, battery, and rear deck interlocks are probably fine and you've ruled them out. Since it turns properly, you also have confirmed that nothing internal to the engine has seized and you have power supplied to the starting system. Since it turns and the second engine runs on demand, you've probably also confirmed that the starting battery has sufficient power.

Try an in-line spark tester and see what you've got as @Babin Farms suggested. If you have spark for each cylinder, then move on to check for fuel from the point of the supply line split to the troublesome engine. The best odds at this point are that your trouble is in the spark delivery system.

I have a new 242 service manual inbound and it should be in soon. I'm guessing your power systems are all good, but I'll look for any engine specific fuses that might be causing you trouble anyway.

 

[aturlik]

The problem has been fixed. My husband pulled the ECU for that engine and replaced with the ECU from other engine worked just fine. Husband reseated the original ECU for the non-working engine and it now is working fine. We believe we has some corrosion build up on the connecters. So we are off to go get some dielectric cleaner and grease to put on all the connections. Thanks to all that gave us ideas.

 

[Bizywk]

Awesome. Glad to hear you're heading back to the water with minimal repair cost.