Fuel in engine oil ?!

[whiterabit]

My friend has a 4.3 Mercuiser on a Glastron boat.<br />In the last couple of days a bit of black smoke that smells like petrol started to come out of the exhaust. I thought this was an electrical or a spark plug problem that I can take care of latter but after a couple hours and a few backfires the engine stopped, it run again for a few minutes than did not fire again.<br />When I tried to start it and hold it on full throttle id does ignite but dies after two seconds.<br />When I checked the engine oil I found it is full of fuel.<br /><br />What do you think could be the problem?

 

[Bondo]

Re: Fuel in engine oil ?!

With the little Info you present,........<br /><br />I'd say the Carb. is in Serious Need of a Rebuild...............<br /><br />For Some Reason,..... It's dumping raw Gas,..... It could be a Stuck Needle Valve.......<br /><br />I'd also Guess that the Sparkplugs are now Totally Carbon Fouled.......

 

[Olds Eddie]

Re: Fuel in engine oil ?!

It could be the fuel pump diaphram has failed allowing gas to enter the carb through the f/p vent hose as well as filling the crakcase. Also if the pump diaphram fails and the fuel filter is partially stopped up the carb would run lean while the crankcase filled up with gas. If the vent line from the 'marine' fuel pump to the 'marine' carb air horn is not transparent, replace it with a piece of transparent fuel hose and see if any raw fuel is present. I am assuming that both of these are marine and not automotive parts.

 

[whiterabit]

Re: Fuel in engine oil ?!

Yes, Eddie I think this makes the most sence.<br />This is what someone at the Marina told me too.<br />I will take the fuel pump apart today.<br /><br /><br />Thanks to the both of you.

 

[Olds Eddie]

Re: Fuel in engine oil ?!

The fuel pump is not considerd rebuildable, however I have taken an automotive pump apart and borrowed the diaphram from it to fix the old one. I didn't want to miss out on an oppertunity to go boating while waiting for parts.

 

[whiterabit]

Re: Fuel in engine oil ?!

ahhhh yes!<br />I know what you meen, i will probably do the same, it will probably take the part 2-3 weeks to get here from the US.<br /><br />What car model is it that you tuck the part from?<br />Or in other words how do I get the right diaphram?<br /><br />Thanks Again !

 

[Olds Eddie]

Re: Fuel in engine oil ?!

My boat had a 5.7 SBC which used a Carter fuel pump. You will have to take yours off and match it up with whats available in your country. You may want to see if Jegs or Summit has something like it on their web catalog. Thats how I determined mine was a Carter.

 

[horsefly38425]

Re: Fuel in engine oil ?!

you will need pump from 4.3 car/truck it should work make sure you drain the engine oil change filter or she my go BOOM

 

[horsefly38425]

Re: Fuel in engine oil ?!

4.3 litter eng

 

[man-of-war]

Re: Fuel in engine oil ?!

whiterabit,you may also need to check your rings, do a leakdown test,I have the same problem.i replased the mechanical fuel pump twice,changed carbs,had both of them rebuilt twice,rebuilt this engine four times within a two summer period.the problem with my engine is, the timing was set at 8*inital it should have been set at 16*inital.I got my self a CRANE hi-6m marine ignition box.<br />if you get the engine started check for crankcase pressour/blowby remove the dipstick and check for air coming out the bipstick hole.<br />lookup this forum for ''man-of-war''<br />also look at speedwake.com for man-of-war.hpoe this helps.

 

[whiterabit]

Re: Fuel in engine oil ?!

Thanks MOW!<br /><br />I changed the pump and started the engine.<br /><br />It seams now that not all my pistons are working, crankcase did not fill with petrol again (or maybe its too early to tell).<br />Now there is only the ignition problem to solve, I think this 2 problems were not connected but maybe I'm wrong.<br />I'll let you guys know.