Engines dies when shifting, need help here
 

Hello! Today was supposed to be the first day of boating since last year. Everything went well for a start, both bigblocks started at once, as usual. When up to temp, I left the dock, went for 5knots (800rpm) for 5minutes, then increased slightly to 1200rpm for a few minutes. THEN, I tried hole shot, but both engines stopped immidiately!

Ok, I put drives in neutral, started both engines, no problem. Applied some throttle, still in neutral, just to check. No problem running very well. Then back to 800rpm, engaged drives and the engines died again! Then tried with higher rpm, 1100, before shifting, but no difference. Engines stopped at once. Tried the same a several times. Tried engines individually, but no difference. I was just about calling for help when making a last try. THEN, it suddenly worked again. BOTH engines. Tried holeshot, worked great. (But then I returned to dock, must fix it before I make any longer runs.)

Anybody has any idea where the problem is? It seemes to affect both engines simultaneously....

Boat is CC Stinger 312, engines are carbed 468's, bravo1 drives.

How old is the fuel in the boat?

Fuel is from last summer. You mean if there is water in it? The strange thing is that it worked, then not, then worked again...

I am nearly positive that you have water in your fuel. Your water sep fuel flilters are probably full of water and enough fuel gan get by to let the engines run a little bit.

Just dump the filters into a clear glass container and watch for separartion to verify. Water will be on the bottom.

Ok, I'll try that. But a bit strange it happens with both engines at the same time.

What's the easiest way of getting rid of any water in the fuel tank? Probably got about 70 gal left....

It's a possibility that you are having an issue with your "shift interruptor switch" if your boat has one. What this switch does is drop the rpms on your motor(s) for just a second when you shift into gear so it's easier on your drive(s). Usually, it is located on the plate mounted on one of your risers that has the shift cable and drive cable attached to it. Someone on here should be able to chime in and explain how to test it. Good luck!

He said it was a Bravo in the first post.

i have about the same problem with 2 different boat.first one was a bad connection behind the dash for the ignition switch as soon as i give some thhrottle engine die cause of more vibrations.second one, moisture in the fuse box,voltage was fine at the ignition switch at 650 rpm but lose it at 1200 rpm.all new fuses and contact cleaner at the fuse box and all is fine.

note in both case it appen to me early in the spring.

Just keep running it and keep dumping the filters. If its just condensation from winter storage, then it will probably take 3-5 times of dumping the fuel filter.

If the engines are using the same fuel tank, then its not strange at all.

Ok, now I have checked the fuelfilters/separators and there was no water.

Very strange this problem. Since either both engines work OR both engines work not, the problem has to be in a system connected to both engines. And as far as I know, there is only the fuel tank. BUT, fuel looks clean.

Therefore, I suspect, it might be some electrical issue, killing the engines when engaging drives. If both engines are at idle, and I try to engage only port drive, only the port drive stops. Same if I only try the starbord side, only starboard engine stops. Then all of a sudden, both engines work again... very frustrating...