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-   -   Flooding/fuel in oil (http://www.mariahownersclub.com/forum/boating-101/269-flooding-fuel-oil.html)

boarder1010 08-28-2007 09:57 PM

Flooding/fuel in oil
 
I seem to be burning an excessive amount of fuel and it smells real rich out the exhaust. It also smells gasy just sitting there. I checked the dipstick and it is hard to tell if I have gotten any actual volume of fuel in the oil but definately smells gasy. The boat starts up real good, seems to run well but a little boggy like it is over-fueling in mid range as well as top end. If the boat sits for awhile after running, even just a minute or so, it seems to flood and I have to give it WOT to start again. Any suggestions on where to start in the carb or what to do? Does anyone suggest flushing the crankcase or just put new oil in after the flooding problem is fixed? I have also heard from some people that it is common nature for and I/O to start a bit harder after sitting for a bit because of all the heat that has no where to go in the engine compartment? Was also told to leave the blower on full time?

Would like to go back out again this weekend but need to get it running a bit better. Does anyone have a rough idea of typical fuel cosumption for the 4.3l LX 4 barrel assuming misc cruising, tubing, boarding etc?

thanks

moondance100 08-29-2007 12:11 AM

Kurtis, 2 things that come to mind are choke and well plugs in the carb base. Check and see if the choke is open when the engine is warmed up. If it is, it's likely the well plug or plugs. These are holes in the base from the casting of the throttle body. There are soft lead plugs pushed into these holes to block them, one could have developed a leak.

I'd get this fixed as quick as possible, that fuel is at least thinning the oil, or worse, raw gas could be running down the cylinder walls rinsing the oil off!

Probably a carb rebuild would be my guess...

Good luck!
Doug

boarder1010 08-29-2007 02:06 AM

How do I know if the choke is open? Just by looking at the butterfly? What if it is closed once warm? How do I fix that?

Thanks

moondance100 08-29-2007 02:32 AM

Yeah, take off the spark arrestor over the carb and see if the butterfly is open when the engine is warm. As far as how to fix it, if you're not pretty mechanical, they're a tough fix. Carbs are pretty complicated and I'm not sharp enough to diagnose a how to on here. If the choke is stuck, that's not as serious as something inside the carb.

I think I'd take it to a shop to get looked at Kurtis...

boarder1010 08-29-2007 02:38 AM

Looks like it is a vacuum operated choke? If the choke was stuck on then the boat shouldn't idle smoothly should it? If it is like a car then it should take a couple pumps to get it started then it should want to choke and high idle until either you manually kick it off or the electric or vacuum in my case releases it? does that sound right?

I just sucked all the oil out and volume wise I don't have any gas in the oil. the oil was nice and thick before I warmed it up as well. I did notice that there is a lot of gas just sitting in open cavities inside the carb near the 2 rear barrels?

What is normal fuel consumption for this boat?

boarder1010 06-23-2008 04:21 PM

Was on the water for the first time this last weekend and still having the same problems. I have been on some other sites and some people say to check the clear tube from the fuel pump? I don't think I have a choke problem as it starts good when cold and runs fine except it seems rich. It starts hard when warm(vapour lock) but I can work with that. I can't be changing oil every weekend and risking damage to bottom end bearing/cylinder?

If the well plugs were leaking how would that cause extra fuel to go through? Where on the base of the carb are these plugs? How do you get them out to replace just encase they are leaking?

What position should the accelerator pump be set at? Mine is set in the middle hole?

boarder1010 06-25-2008 06:05 PM

Is there no one out there that has any insite on this? I have since checked and I don't have a clear tube from pump to carb like some others are talking about. I have noticed excess fuel pooling in cavities on either side of the butterfly's(4 barrel area-rear of engine??)

Please help.

WetWilly 06-26-2008 08:30 AM

Hi boarder1010,

I assume you have the 4.3 and your right, you don't have the clear tube. It's for machanical fuel pumps and yours is an electrical pump. If I remember correctly, the tube is connected to the dry side of the pump and to the carb. In the event of the diaphragm in the pump breaking, any gas flowing into the dry side on the punp would be sucked directly into the motor causing it to flood and shut down while preventing any gas to pouring out into the bilge and also giving a visual indication the fuel pump was compromised.

As for the choke, I think what moondance100 was referring to, was whether your chock was opening fully when it was warm. When cold the choke should be almost or fully closed depending on the MFG's setup and it should be fully open when warm, if it was only partially open when warm, it could cause the symptoms you've described. From looking at the diagram of your carb, your choke system is pretty simple in design, the only issues I can see would be ether a bad diaphragm or some kind of binding in the choke linkage if the choke is the problem.

I have an idea or two as to what could be your problem but I am in total agreement with what Moondance100 said, unless your familiar and equipped to service the carb yourself, I too, suggest you consider seeing about getting it professionally serviced.

Lastly, a picture of your carb shows the accelerator pump rod in the second hole as well.

WetWilly

GrayDog 06-27-2008 12:09 AM

It could also be a problem with the float. Any way you look at it, unless you are mechanically inclined, you're probably best leaving this to your mechanic. He'll have the tools and the knowledge to repair it correctly and get it adjusted properly.

boarder1010 06-27-2008 03:11 AM

Thanks for all your feedback. I ended up taking the carb apart last night(nothing to it). There was a fair amount of gummy gas deposits floating around but no jets were plugged and the needle/seat assemblies appeared to be in good shape. I didn't think to try and test the floats but I did make a minor adjustment to one of them that was a little out. I set it to shut fuel off sooner. The floats in this carb are the brass looking metal floats that appear to be braised/welded together. There was nothing evidently inside the float (assuming possible hole or crack). However I did note that there wasn't as much fuel in the bowls as there should have been which means float or needle and seat? I am hoping there was either a minor problem with that one float or possibly some crud getting caught in one of the needle/seat assemblies?

The other interesting note from WetWilly is the choke. When I removed it I made note of the choke position etc and when cold the choke plate is completely closed. But I seem to remember it NOT being completely open once warm. It was open but only a small amount...unless it doesn't actually open to straight up/down. I am on my way out the garage to install the carb back on and check things out with the choke. It appears that it is a combination of vaccuum and manifold heat that opens the choke plate up once warm? Any more insight on the choke would be great.

Thanks


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