|So I have a really weird starting issue. My boat won't start in the water, acts like the batteries are dead. Pull it out and it will fire up. Now I assume this has something to do with back preasure some how.....Now things I tested for. Batteries are all good. Charging system all good. When its in my driveway hooked up to Fake a Lake it fires right up. But as soon as I dip it seems to barely want to crank. I'm lost to even know where to start on this. I assumed it was the batteries or alt but both checked out fine when tested. thanks|
|By Jos (jtnz) on Wednesday, July 08, 2009 - 7:16 pm:
|Starter? It might sit at a different angle when in the water. We've had the same problem, our boat is a bit of a trailer queen sometimes will work sweet hooked up to the hose but 5 minutes down the road at the launch no go. We ended up replacing all the accessories on the motor one by one.|
|If it was the starter how come it starts first turn of the key everytime out of the water but as soon as I dip it seems to act like its low on juice? I could understand if it was a starter if it did it more often in and out of the water....|
|I don't think its backpressure. With no ballast, your exhaust shouldn't be more than an 1" or two in the water. |
Sounds like something's shorting out when you drop it in. Any changes to your electrical system?
|No changes besides some stereo equipment upgrades but it was working fine after that.|
|I would check grounds. Boat sets at a different angle in the water and that could cause issues with a ground that is slightly loose. With the current going to the starter it doesnt take much of a loose ground before it will not start. I had some issues on my boat where I forgot to tighten some wires down on a distribution block. |
Hope this helps
|I'll check my grounds but it dosn't make since that it starts out of the water on a flat surface and once in the water it dosn't?? Plus it fires right up on the first crank. In the water it takes awhile to crank over, thats if it dosn't run out of battery juice. We have to be careful and not crank it over and over before it dies. I'm taking it into the shop, they were just as puzzled when I told them the the problem.|
|Just a thought. When you start the boat in the water, is it sitting on the trailer? If so it could be the incline affecting things some how. Cause I'm assuming in the driveway it's sitting on a flat surface.|
|Is it a Inboard/ outboard|
|No the boat is in the water off the trailer when it does this. Its a Ford Indmar 351 Inboard. I'm stumped on this and can't think of anything it could be where it would happen only when its in the water? This is a stupid question but could it be somehow related to the fact that something is causing the water not to flow correctly? Possibly a compression issue... I have no idea just throwing out ideas.|
|The same happen after working on distributor. I adjusted the ignition timing in the driveway and everything worked great. Then I took the boat to the lake and couldn't get it to start. Luckily i had all the tools with me so i hooked the timing light and readjusted the timing. It was way off. After that ran like a champ. |
The way i figure, because you change exhaust preasure by putting your stern 2 feet under water your timing changes too.Cheack your carb too..
Last case senerio, start boat on trailer and back into water , see if it stalls..
Best of luck
|Try and start it on the trailer on a hill so that its sitting on an incline to see if that has anything to do with it.|
|Good points Kevin. That is what we did, We started the boat and backed it down the ramp running because we couldn't get it to start in the water. Never missed a beat once in the water... We just put a brand new carb in the boat and it was running perfect and 3 trip out started doing this. I'll have them check the timing, I had no idea that under water the timing changes. If it was on a incline and didn't start what would that be caused by?|
|So my friend brought up the question of lack of exhaust preasure do to the motor getting tired? Could this cause this to act up starting? WHen the boat is up and running it runs like a champ and shows no signs of change in sound or throttle response? I haven't done a compression test on the motor since I bought it though.|
|There is no way that the water could alter the timing. |
You have said that it acts like it has a dead battery when you have it in the water. I think this would rule out any ignition or fuel related problems.
Does it do this all the time while in the water, or just the first time after you launch? If you do get it started, does it run OK? If you shut down, and then try to restart right away do you still have a problem?
I am thinking that you might be getting a hydrolock situation. With the boat on the trailer there isn't any water around so it is fine. You put the boat in the water and now the water level is keeping lake water in the engine. If there is a leak, like a head gasket or manifold, then water can leak into a cylinder which would make it very difficult to crank over.