Port Engine will turn over but not start

[DFDJETBOAT17]

Hello Yamaha boaters. I’m in a predicament with my 2011 SX240. Took it out about week ago and ran fine, went to use it yesterday started the starboard engine, started up. Went to go start port engine and would only crank over and not start up. Gave the engine some throttle didn’t work. Checked the safety clip by throttles, nothing. Checked clean out locker kill switches and even crawled into the locker and switched around the kill switches (starboard kill switch hooked into the port engine and vise versa) again only the starboard engine fires again. Checked all 4 plugs for spark, they were great!( just changed plugs and oil this year). Checked the fuses and all were good. Am I missing another kill switch or fuses? Or could be a fuel issue?? Help!! Thank you!

 

[Beachbummer]

Can you unplug the lanyard switch to troubleshoot? I had the same thing on my 08 and unplugging the lanyard switch was the tell that the switch was bad.

 

[anmut]

Start with the basics: Fuel, spark, compression. Then onto fuses, relays, and safety switches.

Your port motor was in Neutral, right? Maybe double-check that there's not an issue with the N detent area?

 

[David Martin]

I'm with anmut check fuel/spark.......... fuel get yourself some starter fluid/spray remove air box from front of throttle body and spray some starter fluid while cranking. Still no fire move to spark plug. At lease one of these will let you know where to concentrate you effort.

 

[Julian]

Welcome Nate! @DFDJETBOAT17 The engine diagnostic FAQ is a great place to start:

https://jetboaters.net/faq/#faq-34

The main problem I've seen with these sorts of symptoms are the kill switch being bad. When you say you checked that, what have you done? Often it just takes unplugging the lanyard and putting it back on a few times.

The swim deck kill switches prevent the engine from turning over - so its not them (they disable the starter). So again...this points to lanyard, which allows starter to turn, but disabled spark.

 

[Julian]

@DFDJETBOAT17 any luck/updates?

 

[DFDJETBOAT17]

@Julian I’ve played with the lanyard a few times, maybe I need to do a little more on it and switching the wires underneath since the other engine does run. Little tied up today but will let y’all know when I have the outcome! Thank you all for the help. Ps should have my YDS trouble shooting/diagnostic guide downloaded on my computer tomorrow

 

[David Martin]

DFJETBOAT good call on the Lanyard switch.......... single switch 4 wires one side of the switch can malfunction and the neutral safety switch is the same way 4 wires. You can swap wires on both and check to see if it brings port engine alive.

 

[Beachbummer]

The lanyard switch disconnects the wires when the lanyard is in place. Just disconnect it from the boat to troubleshoot. If it starts while disconnected, It's the lanyard.

 

[PaulyB]

The swim deck kill switches prevent the engine from turning over - so its not them (they disable the starter). So again...this points to lanyard, which allows starter to turn, but disabled spark.

This is incorrect. The switches on the back of the swim platform have two functions, one to cut spark and one to prevent the engine from turning over. It is possible for the switches to be depressed far enough to allow the engine to turn over, but prevent the spark to start the motor.

 

[buckbuck]

That is interesting @PaulyB
Is this true with our older boats or all Yamaha's?

 

[PaulyB]

I would say all Yamahas. It looks like the cleanout hatch switches in a 2007 have the same part number as the 2020 boats.