Yamaha 40hp 2018 injection F40LA

[Yannick]

Hello
we have a 40HP F40LA outboard from Yamaha, its a 2018 with 400hours, injection engine.

Every morning shes cranking for about 5-6sec before she start, once start it works fine for all day, no rough idlle, not rough wideopen, works A1

- The fuel prime bulb is hard.
- I removed the output tube from the fuel pump and when I start the engine theres a lot of fuel coming out, fuel pump works fine.
- I changed sparkplugs for the same one requested by Yam : NGK DPR6EB-9
- Gaz is clean (always run with ethanol, 92octane), all fuel filter are clean too.

I can not figure out why its hard to start it when its cold, then works fine all day long after.

Can it be the spark plug ? I have in mind to do a cross reference and purchased a better quality one:

• NGK DPR6EB-9 replacement spark plugs
• Autolite 4164
• Autolite XS4164
• Brisk BR15YC
• Denso 4125
• Denso X20EPR-U9
• Yamaha 94702-00418
• Yamaha 94709-00418

Any suggestion to help me
thanks

 

[Yannick]

sparkplug are correctly gap as well

 

[blufeb95]

Is the starter weak or the battery weak, what viscosity of oil are you using?

 

[Yannick]

starter is fine, it crank very well, batterie also in good shape , i tested it.
Oil = amsoil 10w30 with approx 80hours

 

[Boomer]

Sounds like maybe fuel is draining backwards to the pump leaving an empty gas line that needs to be refilled.

 

[wpod]

Sounds like maybe fuel is draining backwards to the pump leaving an empty gas line that needs to be refilled.

Or is there some kind of self prime at start up?

 

[Yannick]

just order a new fuel prime bulb, maybe it just that,