# Fuel Starving Issue on Maverick / Yamaha F40LA



## bboyet2 (Nov 16, 2013)

I'm having an issue with fuel supply to the motor. This is on a 2012 Maverick HPX Micro, with 2011 Yamaha F40LA (fuel injected) outboard.

Motor runs fine for first part of day, I usually run about 3-5 miles to my first fishing spot. When I go to jump on plane to hit spot #2, I get up and can usually run about 2 minutes, before the motor starts stalling, and I lose RPMs. It will fluctuate wildly, until it eventually drops way down and I throttle down. If i reach back and pump the bulb while its running, it usually jumps up in RPMs (as it should). Sometimes this will be enough to get the boat back up to 5200-5800 RPMs, sometimes it doesn't work at all. Yesterday after trying the "bulb pumping technique" over and over with no success, I just decided to idle in. After about 3 minutes of easy idling, I decided to just throttle up again to see if there were any changes, and it jumps up to normal RPMs and does great.

I've already installed a new bulb, new anti siphon valve and new fuel / water separator. My repair guy also installed a part on the motor (cant remember what it's called, but its where fuel line attaches INSIDE the cowling, maybe a regulator or something?). He did a compression test running it and said it was losing pressure right there. Still didn't fix the problem though.

Repair guy says it may need a new fuel pump. But he's just guessing, and again, it seems to be intermittent. He couldn't even get it to stall out last time he ran it. Seems unlikely to me the fuel pump would work fine sometimes, then fail after my initial run.

Any ideas? Also, I use Premium at the pump, I don't have access to ethanol-free fuel. But the boat is used 3 or more times a week, and fuel stabilizer, so it doesn't sit.

Thanks in advance


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## yobata (Jul 14, 2015)

Have you checked the connection at the tank? I had a similar problem and there was a small leak at the fitting from the tank to the fuel hose which caused an intermittent problem similar to the one you describe


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## [email protected] (Nov 13, 2012)

I may know what the problem is, I had the same issue on my F70 and they are very similar set ups. When I posted my issue a guy with your boat and set up responded and helped me find the problem. Give me a call\ Joe - 954-818-1962 and I will walk you through it - it sounds exactly like the same problem I had. Would have been impossible to find.


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## Goatlips (Jan 9, 2013)

http://www.noonsite.com/Countries/USA/yamaha-outboard-safety-recall 
We were having the same issues.


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## tarponandtailers (Jun 7, 2020)

bboyet2 said:


> I'm having an issue with fuel supply to the motor. This is on a 2012 Maverick HPX Micro, with 2011 Yamaha F40LA (fuel injected) outboard.
> 
> Motor runs fine for first part of day, I usually run about 3-5 miles to my first fishing spot. When I go to jump on plane to hit spot #2, I get up and can usually run about 2 minutes, before the motor starts stalling, and I lose RPMs. It will fluctuate wildly, until it eventually drops way down and I throttle down. If i reach back and pump the bulb while its running, it usually jumps up in RPMs (as it should). Sometimes this will be enough to get the boat back up to 5200-5800 RPMs, sometimes it doesn't work at all. Yesterday after trying the "bulb pumping technique" over and over with no success, I just decided to idle in. After about 3 minutes of easy idling, I decided to just throttle up again to see if there were any changes, and it jumps up to normal RPMs and does great.
> 
> ...


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## tarponandtailers (Jun 7, 2020)

My Yamaha F70 is having the exact same problem, what did you eventually discover? How did you finally resolve?


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## finbully (Jan 26, 2013)

Get it on a scope instead of blindly throwing money at it.


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## tarponandtailers (Jun 7, 2020)

finbully said:


> Get it on a scope instead of blindly throwing money at it.


Not sure what you mean? My wet test with mechanic ran fine, so now Innot sure what yo do.


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## finbully (Jan 26, 2013)

tarponandtailers said:


> Not sure what you mean? My wet test with mechanic ran fine, so now Innot sure what yo do.


Did they scan it with a Yamaha diagnostic tool?


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## tarponandtailers (Jun 7, 2020)

finbully said:


> Did they scan it with a Yamaha diagnostic tool?


No, they tested fuel, cleaned filter, and wet ran. What is the diagnostic scanner tool?


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## Capt.Ron (Mar 5, 2014)

Y’all realize that this is from 2013?


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