Boat bogging n dying out
 

I have a 91 diablo with a 4.3 and mercury outdrive. It was running perfect n then we went on a nice slow 10 mile cruise at idle and then when i went to jump on itn got it to 3000 rpm it started bogging n slowly died out. n then it starts right back up. n does the same. I put fuel treatment n it n it still does it. any suggestions plz let me know what i might have to do ty

Re: Boat bogging n dying out
 

Does it backfire or any other issues?????

Re: Boat bogging n dying out
 

nope it runns great at idle n low speeds but when i throttel down to get some speed it gets to about 3,ooo rpm n above it starts to bog n just slows n dies outn then it fires right up n runns great. i even had it n neuatral n revved it up n it had to probs but when i start goin that when it dies

Re: Boat bogging n dying out
 

Ok, will it rev past 3k, if you go really slow with the throttle? If so, possible accelerator pump in the carb??? Or weak ignition issue / coil?

Accelerator pump can be checked by looking into the carb and opening the throttle (air filter off). You should see a nice squirt of gas.

Doug

Re: Boat bogging n dying out
 

How do I do it with it out of the water. Before r long slow cruise the thing ran awesome for the13 hrs I put on it. Should I also change the plugs because the rip off marina we were by said it could be the plugs also.

Re: Boat bogging n dying out
 

Slowly or fast throttle it still dies out

Re: Boat bogging n dying out
 

Could possibly be plugs? Due to the load on the engine that could cause it to fail but it probably backfire a little...

You could purchase "mufflers" they slip on your outdrive and allow you to run the engine using a garden hose to keep it cool...

Also, the boat shouldn;t have to be running to check to see if the carb is squirting gas..

-Doug.....

Re: Boat bogging n dying out
 

np ty the mufflers are those the things that u use to winteize it.looks like the thing a doctor wears to check ur heart n chest. ill do the plugs and take the airfilter off and see if the gas is squirting down. ty n any other pointers would help ty.

Re: Boat bogging n dying out
 

Yep, attach the hose. Slide it over your intake holes ( make sure to lower the drive) turn on the water and running boat in the driveway..... :)
How's your fuel / water filter???
Boats r hard on ignition components so have you replaced cap, rotor, wires plugs recently??

Re: Boat bogging n dying out
 

No I haven't done any of that. How do I find the parts r they the same as a 4.3 car engine. I'l do all that stuff before I consider any carb problems. It's a 91 4.3

Re: Boat bogging n dying out
 

Don't take this the wrong way but: DO NOT USE CAR PARTS ON A MARINE ENGINE! Boat parts are "marinized" to prevent sparks and keep your boat from becoming a bomb on the water. Also, the muffs are good for determining SOME engine problems.... but without the added drag of pushing the boat through the water, it may not bog down. Just keep that in mind while diagnosing. Hope you figure it out, keep us up to date.

Re: Boat bogging n dying out
 

How's it going? I would try to fugure out whats going on before you worry about parts..
And I agree wth the above post....

-Doug

Re: Boat bogging n dying out
 

You have to troubleshoot:

It's a fuel/spark issue
check spark plugs for cracks/proper gap [0.045]
check/change fuel filter
Check ignition/plug wires

STILL?
check fuel pressur & vac
Check/clean carb

Still?
Check Compression
Check Timing

Still?
bring to mechanic

Re: Boat bogging n dying out
 

I recently bought a 96' 190 Z SE and it ran great for the first few weeks. This past weekend my wife and I took a cruise from Dubuque IA to Prairie Du Chien WI (about 50 miles) averageing about 35-38 MPH. It was awesome up until my boat started the exact same problem. I fuel filter, fuel/water sep filter and added a can of sea foam but no dice. I delivered it to a shop this AM and will report back their findings. Hope it's not too major!

Re: Boat bogging n dying out
 

This may sound off the wall but what about a dead short. I was up @ Powell recently and was allowing the kids to get in between the wheel and me to drive. Long story short, it ran great all day or week and all of a sudden it would sputter & stall. I was thinking I got bad fuel, water in fuel all kinds of things. Here the kids had rotated the knob switches for eng comp blower and the switch for the run & park lights, also including the ignition switch. Somehow the knob switches had been rotated to the point of causing a bad connection in some butt connector wiring repairs which was done by the previous owner. Anyhow I tied a string around that particular wire loom and it ran great the rest of the last day. Apparently either the rough ride from running at speed and or the kids bumping or playing with the switches had worked things loose to the point it would intermittently cut out. Every time you hit a wave or wake it's bang bang and hard on wire connectors. Sorry to go on but on boats always consider wiring, especially when things do not seem to make sense.

Re: Boat bogging n dying out
 

Did you all ever figure out the problem? Seeming to be having the same.
John

Re: Boat bogging n dying out
 

I had the same issue and replaced my ignition coil and the problem is long gone. I have put on many hours since! Hope this helps.

Re: Boat bogging n dying out
 

I had a similar problem. Turned out to be the Oil Sending Unit wire was loose. I discovered this after i replaced plugs, cap and rotor, fuel filter...
The oil sending unit on on the right side of engine- not too hard to reach. The oil sending unit's job is to shut off fuel and spark if it senses low oil pressure- but my wire was loose enough that past idle- maybe vibration or whatever- lost contact and made it bog down and die.
Hope that helps.

Re: Boat bogging n dying out
 

Sounds like points to me.

Re: Boat bogging n dying out
 

No points , but viable shot!:wink_thumbup: