OMC 350 king cobra carb issue i think?

[Tnstratofam]

Ok sports fans here goes. We own a 1988 Stratos 2000XLS with an OMC 350 with a king cobra outdrive. This is our families first boat, I know I already here all the sighs from the OMC haters out there, live with what Ive got. Anyway we've had the boat out about 4 times this year with no problems until we ran it out of gas about a month ago. "Note to self fix fuel gauge." So we get her home refuel her and the next time out everything's going all fine and then she just bogs down and dies. I could restart the engine, but when I put her in gear she just stumbles and dies. The engine would rev ok in neutral but nothing in forward or reverse. Got towed in. get home check paper fuel filter in carb ( Rochester Quadrajet ) it looked nice and clean. changed water fuel seperator filter, it did not look great. Engine started fine on muffs in the driveway so we went back out. Again boat ran fine for 20 minutes or so and died. Same problem as before will start and rev fine in neutral, but dies in gear. The one thing I did notice was that as it was building up speed to plane out it seemed the carb or engine was struggling to get up to rpm. I have been reading some of the forums on here for quite a while and am new to iboats and boating in general so ahead of time I thank you all for any and all support you give all of us newbie boaters. I'm planning on draining the fuel tank and checking the lines to see if any of them are blocked or corroded. I will probably also pull the carb and clean it at the least. Where to go from there? Any help would be appreciated. Happy boating to all.

 

[Celtichawk]

Re: OMC 350 king cobra carb issue i think?

Change all filters, it's possible even your anti-siphon valve on fuel tank, fuel pickup lines clean them or change it, as well as clean that carburetor. Sounds like you sucked up so dirt and debris from bottom of tank just waiting to tear that fuel system up when you ran it empty.

Oh and for the cost of a fuel gauge don't do that! Bad day and save you cash from a tow unless you paid for tow assist already but even then.

Good luck let us know.

 

[Renken1]

Re: OMC 350 king cobra carb issue i think?

Anti siphon valve? Is that located externally, or inside the tank?

 

[Celtichawk]

Re: OMC 350 king cobra carb issue i think?

Main part of it is internally, however it's the elbow looking fitting that is attached to the fuel pickup tube and screws into the usually 3/8" threaded holes in top of fuel tank. It's a brass/aluminum fitting that has a check ball or ball bearing inside of it. Sometimes that ball bearing gets stuck or clogged up.

More experienced people on here will explain in depth. Now it didn't fix my problem but there is another thread newer one that the guy changed out filter in carburetor and the anti-siphon valve and he was back on water with little to no issues. He didn't specify which one was the culprit but its rather inexpensive so might as well check it and/or replace it.

Here is a example and I'm sure Iboats sells them so you can order from them too!

http://www.jmsonline.net/moeller-fuel-pick-ups-4fw2036.htm?gclid=CNj-qNevm7kCFTFgQgodq20AOQ

 

[MyBad]

Re: OMC 350 king cobra carb issue i think?

Not to hijack the thread, but the Anti-Siphon valve is attached to the tank itself? I am having a tough time figuring out where exactly it is?

 

[Celtichawk]

Re: OMC 350 king cobra carb issue i think?

Like I said before it is threaded into the tank so yes its attached but can be removed. It is possible that some might not even have one. If you have the small round plastic covers in your deck that can unscrew that should grant you access to your fuel tank fittings and such. Then you will see the fuel line coming off tank but attached to that anti-siphon elbow brass/aluminum fitting. Let me know.

 

[MyBad]

Re: OMC 350 king cobra carb issue i think?

Thanks I located it. Thank you very much.

MB

 

[Tnstratofam]

Re: OMC 350 king cobra carb issue i think?

I won't get a chance to pull my tank or lines until this weekend, but I will be sure to post what I find. I will be checking the anti siphon valve for sure. Hopefully it won't lead to as big a mess as my stuff usually turns out.

 

[Tnstratofam]

Re: OMC 350 king cobra carb issue i think?

Ok so I puled my fuel line, anti siphon valve, and cleaned the carb. The anti siphon valve was clear and seemed to be working fine. The fuel line was also clear. The vent line had gas in it. What I mean is when i blew through it gas came flooding out of the vent. Quite a bit actually. I don't know if it may have a low spot that acts like a trap or if it just got in there from the last time i filled the tank or when we took it out on the water. The carb was clean as a whistle. I don't know if the vent line having that much gas in it would have caused my problem or not. I can't start the boat right now because I managed to break the rotor button on my distributer today trying to get it off and I won't get a new one until tomorrow. So I guess I will take the boat out and give it a try maybe later this week. Just wanted to update the thread. Would appreciate any other advice on where to look. Also I did replace the fuel filters, and checked my fuel pressure. Everything seems ok. Could a blocked vent have caused my problem. I may have overfilled the tank after I refilled it when we ran it out of gas which may have filled the vent with fuel. So if it has a low spot creating a trap that would explain the vent getting blocked I think. Or am I way wrong on this?

 

[Tnstratofam]

Re: OMC 350 king cobra carb issue i think?

Ok sportsfans here we go took the boat out today and everything was going really good. We let the boat idle for a while and ran the throttle up a little to check how the engine responded. Everything went well. Boat accelerated good planed out good engine sounded good and strong. After running for about 10 minutes we headed out away from the dock and I gradually worked my way up to wot. The boat ran great good acceleration good sound to engine and she planed out good. After about 20 minutes or so I stopped and checked the idle again everything working good Coil nice and cool engine running smooth. We started back toward the docks and that's when the trouble started. The engine started running rough I could get it to idle but when I would start to accelerate the engine would stumble and start to die. the carb would make a hissing sound when it would get ready to die. The more throttle I gave it the worse it ran. At idle the engine sounds good and there is no hiss from the carb. So I'm at a loss now as to where I need to go. Total carb rebuild? New ignition components? The Admiral and I are at our wits end. We've got big plans for this boat and my mechanical skills are really being put to the test. Any help will be appreciated. Thanks to all.

 

[bonzoscott]

Re: OMC 350 king cobra carb issue i think?

Check that filter at the carb again. If you find crap, probably a carb clean / rebuild. But to prevent it from happening again, total clean of the fuel system. What you describe sure sounds like fuel starving. If you don't find crap in the filter, check for spark.

 

[Tnstratofam]

Re: OMC 350 king cobra carb issue i think?

Could the filter screen in my tank be getting clogged? The filter to the carb was clean. I didn't pull my tank just wondering if there could be some crap floating around in it that got dissloged at the beginning of my mess. Also even though the anti-sihpon valve seems to be working could it be getting clogged with stuff that falls back into the tank when I pull it to check it? I didn't pull the tank because it was almost full, but I'm thinking I may need too just to be sure.

 

[bonzoscott]

Re: OMC 350 king cobra carb issue i think?

Could the filter screen in my tank be getting clogged?

Yes it could. Pull the pick up and anti-siphon valve at the tank, see what you find. Also, try and look in the tank with a flash light. You may see evidence of trash.

 

[Tnstratofam]

Re: OMC 350 king cobra carb issue i think?

I just wanted to give a final update to this thread. The Admiral and I have decided to restore our troubled craft so I will be posting future info on my restoration thread when I get it started. Also I pulled the anti siphon valve and fuel sending unit from the tank, wow what a mess. There must have been a whole bunch of fuel gremlins living in that tank it was nasty, I'll have to post some pics when I get a chance. It will server as a good reminder as to why you should be careful where you buy gas from. Because it is a belly tank had I not run it out of fuel it may not have given me much trouble, but once it was emptied and I refilled it I stirred up a hornets nest to say the least. Thanks for all the help. Pics of inside the tank coming soon. Also for all you non believers listen to the advice given here. It can save you alot of heartache down the road. Just Sayin!!:facepalm:

 

[jerryjerry05]

Re: OMC 350 king cobra carb issue i think?

That's too bad.
Usually this can be avoided if the tank is left full when not in use.
Also Ethanol additives or a fuel stabilizer can be helpful too.
Condensation can hurt a lot!!