Carb Spewing Fuel, Auto-Choke Stuck?

[BLKNTAN]

Hey guys,<br />New to the forum. I have an 87 Sea Ray Seville 19½' ski boat, with an inboard/outboard Mercruiser 4.3L (Thunderbolt Ignition, Power Steering). I thought the battery was dead, so we tried jumping it. I think now that it's "hydrolocked", since the motor tries to turn over, but is very sluggish.<br /><br />We took the air cleaner off the top, and watched the carb. It spews about ½ pint of fuel during startup, but only when we leave the choke open. If we manually close it, it doesn't spew the fuel.<br /><br />I'm not familiar with carbeurated engines, but I'm willing to do some wrenching. This is the first time I've had any fuel/engine problems since I've owned the boat (1992). Do I need to replace the carb, clean the choke, what? Please, point me in the right direction...<br /><br />BLKNTAN<br />87 Sea Ray, Tellico Harbour Marina, TN

 

[BLKNTAN]

Re: Carb Spewing Fuel, Auto-Choke Stuck?

Just a reply to subscribe to the thread. Sorry.

 

[Tyler H]

Re: Carb Spewing Fuel, Auto-Choke Stuck?

I was looking at the boat with him. We took off the air cleaner. It readily cranked at first and almost started, but I was surprised to see an obscene amount of gas dump out of the tube at the top of the carb and into the intake. The choke plate wasn't closed all the way. <br /><br />It dumped about two shotglasses full of gas out of that tube every time the engine turned over. When I pushed the choke plate closed, no gas came out of the tube, but it was waaay flooded by that point.

 

[Fishermark]

Re: Carb Spewing Fuel, Auto-Choke Stuck?

Sounds like a stuck needle valve. You can try tapping the side of the carb lightly with a small hammer where the fuel line goes in. (Note I said "lightly" and "small" ). Another tip is to cover the top of the carb with your hands while cranking - the vacuum sometimes helps to "unstick" things. (Again, a word of caution - be careful of a backfiring carb - don't do the "hands over the top" trick if the carb is backfiring ). Otherwise, taking it apart may be your last option.

 

[rbezdon]

Re: Carb Spewing Fuel, Auto-Choke Stuck?

Just a note, the engine is NOT hydrolocked if it turns over at all. Hydrolock gives the same symptoms as seized, the engine will not turn even a little bit. The fact that you get sluggish turning and fuel flow says you have a different issue most likely too much fuel or lack of ignition.

 

[BLKNTAN]

Re: Carb Spewing Fuel, Auto-Choke Stuck?

So, should I change the plugs, and (lightly) beat on the carb next to the fuel line? What spark plug and gap is recommended?<br /><br />It still seems like a wholelotta fuel... Maybe the fuel pressure regulator <br /><br />Can someone give me a rough idea of what kind of carb i have, how I could go about rebuilding the carb, what it would cost, and what parts I would need? THANKS !!!

 

[rbezdon]

Re: Carb Spewing Fuel, Auto-Choke Stuck?

Rebuilding a carb in general is fairly simple if there are no major mechanical problems like warping, cracking or severly worn bushings etc. The part issue is straiht forward as there are rebuild kits sold for most carbs which include all of the parts you need, plus the carb to manifold gasket and replacement filters. Basically, rebuilding the carb is remove and tear down, inspect and clean, clean, clean, clean, you get the message. There are some tiny passages which are difficult to clean with out the right equipment but if you find your carb that dirty, I think you'll know it. Then you replace all of the rubber and gasket parts. In your case, I would likely replace the float too if it doesn't come in your rebuild kit. Then reassemble, put a new gasket on the intake manifold and install all of the hoses and linkages exactly as they were attached when you removed the carb. You're other option is to buy a rebuilt carb and just swap it. This cost a bit more but is easier and usually comes with a warranty. But first and foremost, you need to know what carbis on your engine. There should be some part numbers somewhere. By the way, a rebuild kit is fairly cheep, in the more than 20 less than 50 range of dollars. A rebuilt carb could be a couple of hundered to 500 (or more) depending on the carb and if you buy new or reconditioned.

 

[BLKNTAN]

Re: Carb Spewing Fuel, Auto-Choke Stuck?

Found a rebuilt one on 3-day order for $519 + S/H + tax <br /><br />I need a 2-barrell MerCarb (sp?) for my 87 Seville. Sea Ray of Knoxville has the rebuild kit for ~$60, the manual for ~$35, and the gasket for ~$3. Do I need the manual if I've never done this before, and will it tell me how to tune it once I get it together?<br /><br />My plan is to go the ~$140 route for the rebuild kit and random parts/tools/fluids so I can go DIY. My buddy said soak it in laquer thinner for a few days, so once I get it off, I'll let you know how it looks.<br /><br />If someone has a manual laying around and is willing to share... LMK.<br /><br />Thanx,<br />BLKNTAN

 

[rbezdon]

Re: Carb Spewing Fuel, Auto-Choke Stuck?

Some of these Merc guys on this site have links to the manuals PDF style. You may lick out there. Tommays and Don S are wizards at finding the Merc documents. Wish it was the same of the OMC I have. Like I said, if all you have is a dirty stuck float, you can do the rebuild no problem. I do recommend using the manual though if youve never done something like this. By the way, something doesn't seem right about the price you got for the rebuilt carb. That sounds like a new price. Google a bit more with the Merc part numbers and I think you might be able to do a lot better. I bought my first repalcement Quardajet 750 CFM 4bbl carb for $550 and now I have found a source for $230. It is a much bigger carb so it would seem logical your 2bbl should be at least in the ball park although I have never priced the Merc stuff. I am sure these postings will bring more comments from the guys here that know better than I do though!!<br /><br />By the way, I just typed in MerCarb 2bbl into Google and found several sites offering the rebild kit for $42, not 60. Do some research before spending the money!!

 

[Fishermark]

Re: Carb Spewing Fuel, Auto-Choke Stuck?

Rebuilding isn't hard... but you need to take your time and take any notes you may need as you go along.<br /><br />Many rebuild kits will come with a set of instructions - or at least an "order of replacement." (In other words, disassemble, clean, and reassemble in this order).<br /><br />So far as soaking it in laquer thinner - I suggest you buy a gallon of carburator cleaner specifically designed for soaking. It will come with a parts basket. You can pick up a gallon at most any auto parts store.