Engine stalls on throttle up

[Steve Moyer]

I know the connections at the batteries are tight. I did question the cable positioning because the original owner took his batteries out to charge before delivery. He didn't seem too mechanically inclined (and the cables are not marked) so I compared them to a posted picture. It was from a boat a few years older but the setup looked exactly the same. I didn't trust those batteries so I bought brand new ones and a charging system. I also found out that he added a amp and sub woofer that was always on because of direct wiring. I now use a wing nut on top of the post to disconnect when not in use.

 

[Steve Moyer]

Maybe I should check the other ends of the leads. While changing the plugs I did double check the grounds bolted to the motors, and all the electronic plug ins, and they were tight.

 

[Bruce]

Perhaps remove the battery cables and check them for corrosion?

 

[Steve Moyer]

Is there suppose to be water collecting in the bottom of the gas tank area. Cuz there is some down there. The rubber strip is compromised in a few areas. Might be causing the water to get down there when I'm hosing the deck down. God I feel like a newborn when it comes to this boat.

 

[Steve Moyer]

Battery cables are clean as a whistle.

 

[Julian]

Is there suppose to be water collecting in the bottom of the gas tank area. Cuz there is some down there. The rubber strip is compromised in a few areas. Might be causing the water to get down there when I'm hosing the deck down. God I feel like a newborn when it comes to this boat.

Yes....you will get some water collecting there...it should drain back to the bilge if you put the boat on the trailer and crank up the front.

And yes...water will sink to the bottom, so the gas on top should be good, you just want to siphon off the stuff off the bottom. I like the prior post that had you use YDS to turn on the fuel pump and pump it out. Perhaps someone in your area could loan you a cable and SW if you are interested in that approach (assuming you haven't started a manual siphon yet). I'd ship you my hacked together cable if you like.....

 

[jawsf16]

My problem was a loose connection at the battery causing both engines to run rough, like rocks rattling in an empty paint can.

 

[Steve Moyer]

Alright, tomorrow I'll siphon out some gas from the bottom and check it. What I'm hearing is the fuel sensor is the best location to access.? I'll also check the other ends of the battery leads. At a separate time..ha ha. Julian, I may take you up on the cable, but I'll try this first. Sure hope its fuel. Electric could get expensive.

 

[ToddW850]

I was trouble shooting an engine issue last year and thought I had a bad fuel pump, or water in my gas tank. I removed the fuel pump and syphoned gas from there. Just make sure you jack the front of your boat up, so if there is water in the gas tank, it will slide to the rear of the tank where you are syphoning. And make sure you get your syphon hose to the bottom of the tank, where the water would be. Good luck.

EDIT: Should be Fuel Sending Unit, not Fuel Pump.

 

[itsdgm]

I agree with @ToddW850. I had a situation last year where I couldnt get the engines to start while on the trailer until I lowered the bow. It seemed that water or debris would move around in the bottom of the tank depending on the angle of the boat. I ended up siphoning all of the fuel out, cleaning both pumps, wiping out the tank and it ran like a champ once the fuel was replaced.

You could try to flush the engines on the trailer but put the bow up as high as possible and see if it runs rough. This would simulate water running to the back of the fuel tank (if there's water in the tank) while coming up on plane while on the lake.

Hope you figure it out soon. Good luck, keep us posted.

 

[itsdgm]

Here's the write up I did on cleaning out my tank. Hope it helps you out.

https://jetboaters.net/threads/cleaning-out-my-fuel-tank-has-anybody-done-this-yet.4492/

 

[Addicted]

The low voltage alarm leads me to believe it is power related. With the weak stators in these motors, could the motors be starving for power under a load if the batteries are not wired correctly? I would normally agree that fuel seems to be the culprit, however you have questioned the battery install and the amps were clearly not installed correctly. Those facts along with he voltage alarm lead me to electrical. I would go back to the battery wiring and make sure you are confident with the way things are hooked up. Maybe add a picture of the way it is currently wired? There should be a ground connecting both batteries together. Is that installed? I have heard of that causing issues, and with both batteries being out of the boat, that cable could be bouncing around in your compartment. Easy to miss when you re-installed batteries.

 

[Steve Moyer]

Thanks again everyone for your help. I think I've now reached the pathetic part of the show. I just went to take a picture of the battery hook ups and noticed that the ground connecting the two batteries was off on the house side. I removed the batteries prior to the last outing and I guess I missed that on the re-hook up. Duh...So that may explain the low voltage alarm I kept getting. I know, on the run before that they were all hooked up. Here is a picture of the current hook up minus the ground that I'll fix right now. The small leads to both batteries are to the charger/maintainer. Thanks addicted. Don't give up on me guys, I'm usually not this stupid.
Ok, second image shows the ground re-connected. I also learned to leave the ground off on the amp/sub instead. Its less likely to spark than the positive. Don't need to add that to my troubles.

 

[Murf'n'surf]

I thought your running issue existed before your voltage warnings?

 

[Steve Moyer]

It did. That just explained why the last time I went out I kept getting the low voltage warning. The poor running problem still exists. I picked up the siphon and a few extra gas cans today. I'll try to tackle the bad gas issue tomorrow.

ITSDGM, Wouldn't it be easier to go into the tank through the fuel sending unit? Follow your instructions of lifting the bow then just fish the tube down to the back/bottom of the tank? That fuel pump removal looks tough.

 

[itsdgm]

It did. That just explained why the last time I went out I kept getting the low voltage warning. The poor running problem still exists. I picked up the siphon and a few extra gas cans today. I'll try to tackle the bad gas issue tomorrow.

ITSDGM, Wouldn't it be easier to go into the tank through the fuel sending unit? Follow your instructions of lifting the bow then just fish the tube down to the back/bottom of the tank? That fuel pump removal looks tough.

Yes. It would be much easier. I take the boat out only a few times a year (towing about 500 miles for 3-4 days on the lake) so I wanted to make 100% sure that I fixed my problem the first time. I ended up cleaning out the fuel pumps and checking for any debris too. All looked good and I actually ran the fuel through a filter and put it into an older car which ran fine on it.

Let me know if you need any info on how I siphoned the fuel out. I took a lot of pics and can post or email them to you.

 

[Steve Moyer]

Great pictures. Can't deny the pump access has advantages. Does that last picture show, the sending unit down pipe?

 

[Murf'n'surf]

Great pictures. Can't deny the pump access has advantages. Does that last picture show, the sending unit down pipe?

Yep, that's the sending unit.

 

[swatski]

Yes. It would be much easier. I take the boat out only a few times a year (towing about 500 miles for 3-4 days on the lake) so I wanted to make 100% sure that I fixed my problem the first time. I ended up cleaning out the fuel pumps and checking for any debris too. All looked good and I actually ran the fuel through a filter and put it into an older car which ran fine on it.

Let me know if you need any info on how I siphoned the fuel out. I took a lot of pics and can post or email them to you.
View attachment 31259 View attachment 31260 View attachment 31261 View attachment 31262 View attachment 31263

@itsdgm You did not clean it half way, did you! Probably cleaner than it was off the factory floor... you could eat off of it, LOL.
Thank you for posting, you guys are so helpful!

 

[Steve Moyer]

Ok, Good news, bad news, time. Good news is there doesn't appear to be any water in the gas. Bad news is back to square one, with the distinct possibility of having to take it to Yamaha. Here is a picture of the gas. Doesn't appear to have a drop of water or debris in it. I used a piece of PVC pipe and fed the siphon hose right to the bottom after tilting back the boat and letting it sit for over an hour.