Bang!

[bsh21wash]

Had the cover off the motor and went to start it and there was a loud bang! After the smoke ball cleared, the valve cover gaskets were exposed. What the hell went wrong here?

 

[DHPMARINE]

Re: Bang!

I'd guess you have fuel (gas) in the crankcase and something ignited it.NOT good.

DHP

 

[Coors]

Re: Bang!

that is an original

 

[tystick]

Re: Bang!

thats not supposed to happen......

 

[Bondo]

Re: Bang!

Ayuh,.........

I'd say she's runnin' Alittle Rich..........

Fuel Pump Diaphram Maybe,..??....

 

[Don S]

Re: Bang!

I was driving my boat all day today no problems... I was on my way back to the dock when all of a sudden my RPMs dropped from 4000 to little under 3000. I stopped checked things out (oil, wires) everything seemed alright. I started to go again and the boat wouldnt go above 3000 RPMs at full throttle??? There was also blue smoke coming out from the back, never did that before. Any ideas?

I think I know what was happening on your previous post now. The fuel pump diaphram went bad, the fuel pump was pumping a lot of raw fuel directly into the carb thru that clear hose and probably a lot into the oil pan thru the pump mounting area. Since there was so much fuel going into the carb, it back fired a little and lit off everything.
Had you noticed any problems idleing? Flooding out easily at low speeds and such problems?
I think it's time to consider removing the engine and dissassembly at this point. Would bet oil seals, pan gasket, and who knows what else also changed.

 

[HT32BSX115]

Re: Bang!

I heard something like either here or on another forum like Trailerboats etc...

Someone said something like "It doesn't hurt to smell a little gasoline in the oil"

I hope this is read by all. There should never be gasoline in the oil. If there is THERE'S SOMETHING WRONG! and it could be somewhat dangerous.

If it blew out the valve cover gaskets it probably turned all the oil seals inside out too!

It's a wonder it didn't blow the oil filler cap off.

This is why they removed the systems from aircraft engines that dumped gasoline into the oil prior to shutdown in very cold weather.

Too many booms!


Cheers,


Rick

 

[bsh21wash]

Re: Bang!

Don... After the first time, it still idled, I only had it running for about minutes after that though. Yesterday I didnt get to listen it after the bang I was kinda spectacle of starting it again. I checked everything and didnt see no leaking oil anywhere. I really had NO problems before this.

 

[Windykid]

Re: Bang!

If the engine is not leaking from anywhere else, the engine needs to be flushed to remove any remaining fuel as to not destroy any bearings or future booms. Change the fuel pump. Refill with clean oil. pull coil wire and crank engine over several times and check for any fuel. pull plugs and check for fuel fouling. doesnt nesicarily have to be the fuel pump diaphram.

Or pull motor out and rebuild.

 

[bsh21wash]

Re: Bang!

How should I go about "flushing" the engine out? What about the valve cover gaskets that are partly sticking out? I'm trying to avoid having to rebuild, but if it's nessacary then I have no choice

 

[Limited-Time]

Re: Bang!

Just drain the oil, and change the filter as you would for a regular oil change. You can pick up a can of seafoam, or the engine flush you add to the oil. Follow the directions on the can. As for the valve cover gaskets you need to change them.

 

[bsh21wash]

Re: Bang!

Alright thanks, I think I will do a compression check first though without warming it up...will this be a problem? No sense in buying a new fuel pump if I might be replacing the whole motor.

 

[Bondo]

Re: Bang!

After you Install a New Fuelpump,...............

Just drain the oil, and change the filter as you would for a regular oil change.

Then I woud just Run It for a few hours,+ Keep a Close Eye on it.....

It'll either be Fine,........ Or Spewing Oil Everywhere.........
It Gas contamination,...... No Need for Any Flushes,..... The Gas will be Absorbed by the Fresh Oil........

If you manage to get a few hours out of it without Problems,...and/ or Oil Leaks......
Change the Oil Again,+ I Think you'll be Good to Go........

Btw,...... The Compression Test probably Won't tell you much about This Issue,......

The Problems are going to be the Soft Parts of your motor,...... Seals,+ other Rubber Parts,.....
Pistons,+ Rings should be Fine,......... Bearings Might be a Problem with that much Gas in the Oil,.....

The Oil Pressure will tell you that during that Few Hour ride.....