Yamaha F115 hard starting once it has been run.

[99yam40]

Re: Yamaha F115 hard starting once it has been run.

if the spark tester show spark then the plug should be sparking unless the motor is flooded maybe and shorting out the plugs.

Have you changed the plugs to make sure they are good
Should be able to measure the voltage into and out of CDI to see if they are meeting minimum specs in service manual.
Should be specs on plug wire/caps in it also

 

[Bamaman1]

Re: Yamaha F115 hard starting once it has been run.

I'm sorry, but you really need a service manual for your engine.

That and your YDS software will point you in the right direction and tell you how to diagnose the sub-systems.

Have you talked to any Yamaha mechanics? Sometimes there are common problems that they immediately know how to fix--because they see them so often.

 

[killoy]

Re: Yamaha F115 hard starting once it has been run.

I tried to start the engine cold on the trailer tonight. I had the Yamaha YDS cable attached to try and help solve the problem. It turned over but would not start. This it the first time it would not crank when trying to start cold. The warning horn also sounded while it was cranking but not starting. I noticed the YDS system had the "engine stop lanyard switch" listed as ON. I think when the lanyard is in place it should be listed as OFF. I raised the lanyard up for a more positive connection, it read OFF on the YDS and the engine cranked. Has anyone heard of a safety switch failing intermittently?

Two other things I notice with the YDS diagnostic system:

1: The "shift position switch" would read NORMAL when the key was just switched on, and it would read IRREGULAR SIGNAL and move the top of the list in the Diagnosis Screen on the YDS when the engine was running.

2: The "oil pressure switch" would sometimes read ON or OFF. What should it read with the key switched on and when running?




Thanks for all the great support with my engine problem.

 

[schematic]

Re: Yamaha F115 hard starting once it has been run.

Old "rule of thumb" with electronics......

"when nothing makes sense, check all ground connections first"

 

[Pas Bon]

Re: Yamaha F115 hard starting once it has been run.

Hmm? I wonder if the kill switch is the culprit?

 

[killoy]

Re: Yamaha F115 hard starting once it has been run.

Problem Fixed: Shift position switch was the problem!

Checked the shift position switch in the engine. When in neutral it was reading open on the multimeter. I adjusted the metal tab on the switch so it was reading closed when the shifter was in neutral. I ran it today and everything seems OK. It does not have the 2 to 3 second delay when starting now. I believe I have fixed the problem. The YDS cable and software really helped as well as all the input on the forum.

I can only guess the reason the horn sounded was maybe the ECM getting confused because the shift position switch was open when cranking and the vibration of the engine during cranking caused the switch to close. This also accounted for the 2 to 3 second delay when the engine would crank.

Thanks,

Kevin

 

[Pas Bon]

Re: Yamaha F115 hard starting once it has been run.

Awesome!

Glad you got it licked!

 

[rc_mahal]

Re: Yamaha F115 hard starting once it has been run.

Problem Fixed: Shift position switch was the problem!

Checked the shift position switch in the engine. When in neutral it was reading open on the multimeter. I adjusted the metal tab on the switch so it was reading closed when the shifter was in neutral. I ran it today and everything seems OK. It does not have the 2 to 3 second delay when starting now. I believe I have fixed the problem. The YDS cable and software really helped as well as all the input on the forum.

I can only guess the reason the horn sounded was maybe the ECM getting confused because the shift position switch was open when cranking and the vibration of the engine during cranking caused the switch to close. This also accounted for the 2 to 3 second delay when the engine would crank.

Thanks,

Kevin

Hi, Good Morning Kevin,

I know this is an old post. I am new to boating and I appreciate any help from anyone here. I have the same problem with my boat exactly like yours and I would like to try your approach with it. Mine is 2003 Yamaha F115. My question is where is the Shift Position Switch? Is this the same as Neutral Switch? What do you mean by "adjusted the metal tab on the switch?". So far I already cleaned VST filter, changed inline filter and water separator filter. Changed thermostat and impeller. After running few miles, I'm having hard time restarting without cooling the engine for like 30 minutes. IU read in some thread about this Vapor Lock but I don't really understand it. I appreciate it if you can post pictures so I will understand better.

Thank you in advance.

Reggie

 

[saltchuckmatt]

Hi, Good Morning Kevin,

I know this is an old post. I am new to boating and I appreciate any help from anyone here. I have the same problem with my boat exactly like yours and I would like to try your approach with it. Mine is 2003 Yamaha F115. My question is where is the Shift Position Switch? Is this the same as Neutral Switch? What do you mean by "adjusted the metal tab on the switch?". So far I already cleaned VST filter, changed inline filter and water separator filter. Changed thermostat and impeller. After running few miles, I'm having hard time restarting without cooling the engine for like 30 minutes. IU read in some thread about this Vapor Lock but I don't really understand it. I appreciate it if you can post pictures so I will understand better.

Thank you in advance.

Reggie

Old, old post. Poster was last on here in 2016.

Click twice on his name (username) and it will take you to a spot where you might be able to send him a direct message if he still has the same email. Once there hit start conversation.

Otherwise, maybe someone else on here might help you out.

Cheers