# 2012 Yamaha F70LA hard start



## Frank Ucci (Jan 20, 2019)

How old is the fuel? Ethanol or not?


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## Smackdaddy53 (Dec 31, 2012)

Run it on a remote fuel tank and see if the issue persists. If it does, it’s something with the outboard, if it fixes it it is something from the tank to the outboard.


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## coconutgroves (Sep 23, 2013)

Key question...

Is the slow start a "laboring start?" Specifically, is the turn over slow, then speeds up as it fires? This could be simply a cold cranking amps issue.

or....

Does the starter and crank sound the same and it just takes a longer amount of time to fire? This could be more a fuel problem like @Smackdaddy53 said.

Those are two different problems and solutions.

My last skiff had this issue on cold mornings. Try to turn it over before putting in the water to make sure it will crank. Mine would throw the main breaker from laboring too much. Needed a new battery with better cold cranking amps. Never did it in the summer, only in cooler temps.


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## glennwilson (Aug 21, 2010)

Frank Ucci said:


> How old is the fuel? Ethanol or not?


Fuel is new. I run boat at least once a week so no more then a couple weeks or so old. It is ethanol.


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## glennwilson (Aug 21, 2010)

Smackdaddy53 said:


> Run it on a remote fuel tank and see if the issue persists. If it does, it’s something with the outboard, if it fixes it it is something from the tank to the outboard.


That is a good idea. Will try.


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## glennwilson (Aug 21, 2010)

coconutgroves said:


> Key question...
> 
> Is the slow start a "laboring start?" Specifically, is the turn over slow, then speeds up as it fires? This could be simply a cold cranking amps issue.
> 
> ...


It is not a laboring start sounds normal just takes several turns of the key a few seconds each time. Battery lives on a charger regularly.


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## glennwilson (Aug 21, 2010)

New symptom sorta, or not symptom. I used boat on Wednesday had the same starting issue first thing at the ramp. Ran fine all the rest of the day. Put it up for the night and decided to try and start it the next morning at the house, and it fired right up. So seems to be when it sits for several days.


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## Mdees88 (Jun 23, 2021)

Are you squeezing the primer bulb until it gets hard before trying to start it?


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## coconutgroves (Sep 23, 2013)

Mdees88 said:


> Are you squeezing the primer bulb until it gets hard before trying to start it?


If the bulb doesn't fill up and get harder to squeeze, replace it. That means it isn't doing the job and getting fuel to the engine. That very well could be it. I've had bulbs before screw up perfectly good days. Make sure the bulb is vertical and as close to the engine as possible.


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## glennwilson (Aug 21, 2010)

Mdees88 said:


> Are you squeezing the primer bulb until it gets hard before trying to start it?


I have pumped the primer bulb till it was full and still had the same issue. Also replaced the primer bulb already.


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## coconutgroves (Sep 23, 2013)

Do what @Smackdaddy53 said and try to isolate the entire fuel line and tank.

If it still does it, go to the low pressure fuel pump and replace the diaphragm, or the entire part. Yamaha fuel issues are sometimes due to that. Easy part to change. Note, this is not the fuel injection pump - but the low pressure pump pulls from the tank (via the priming bulb) and sends to the injection pump. The bulb can work all day long, but if the low pressure isn't doing its job, the engine won't get enough fuel.






Yamaha Outboard Parts by HP 70HP OEM Parts Diagram for Fuel | Boats.net


Buy OEM Parts for Yamaha Outboard Parts by HP 70HP Fuel Diagram




www.boats.net





Diaphragm is #34. Entire pump is #27.


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## glennwilson (Aug 21, 2010)

So i want to update incase this helps someone else. So after replacing all the fuel related parts and having no change. Had a new symptom which was getting just a click when trying to start first thing. like a dead battery. So then I went in the direction of an electrical issue. Had battery tested and it was fine so I started going through the wiring. Checking and cleaning connections. In that process i started cutting zip ties and inspecting the wires themselves. Finally found an issue. There was a cut in the main ground wire running to starter. It was made by coming into repeated contact with a hose clamp from the fuel line. When motor turned back and forth. Very sketchy ha. Almost cut through the hot side of the wire too. So replaced main starter wires a boom no more problem. Starts fine runs fine no issues anymore. So I guess if you have a weird starting issue make the ground wire a first thing to inspect. Hope this saves someone some time.


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## glennwilson (Aug 21, 2010)

I also fixed the hose clamp issue so no more contact in future.


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## DBStoots (Jul 9, 2011)

glennwilson said:


> I also fixed the hose clamp issue so no more contact in future.


Like Bob LeMay says, "Aren't boats fun!"


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## TheFrequentFlier (Feb 17, 2016)

glennwilson said:


> So i want to update incase this helps someone else. So after replacing all the fuel related parts and having no change. Had a new symptom which was getting just a click when trying to start first thing. like a dead battery. So then I went in the direction of an electrical issue. Had battery tested and it was fine so I started going through the wiring. Checking and cleaning connections. In that process i started cutting zip ties and inspecting the wires themselves. Finally found an issue. There was a cut in the main ground wire running to starter. It was made by coming into repeated contact with a hose clamp from the fuel line. When motor turned back and forth. Very sketchy ha. Almost cut through the hot side of the wire too. So replaced main starter wires a boom no more problem. Starts fine runs fine no issues anymore. So I guess if you have a weird starting issue make the ground wire a first thing to inspect. Hope this saves someone some time.
> View attachment 192166
> View attachment 192166


Damn nice work.


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