4.3 lx stalling problem
 

After running the boat for about an hour on the lake pulling skiers, I picked up my buddy out of the water and took off. when it got to about 3000rpm it started lurching ( rpms up then down). This happened for about 20min and then it would not go over 2000rpm at wot. It would idle fine and start fine. Now it stalls as soon as I put it in gear. Pulled the cover off and the previous owner bypassed the fuel/water seperator. I took it to the local marina and they said that they think its the carb. I just wanted to see what you guys think. Don't want to start throwing money at it and hoping.....

By the way. it starts fine and idles, pulled fuel line to carb and when I turn the key on it pumps fuel. Is it possible that something has clogged the jets or the accelerator pump?

Re: 4.3 lx stalling problem
 

Ok. I just went out and started the boat and as always, fires right up. If I slowly give it gas then it will rev up. If I throw it down then it will stall out. Sounds like the accelerator pump to me. I would love a second opinion still or someone to tell me Im on the right path. Is there any way that I can just replace the accelerator pump and the main gasket?

Re: 4.3 lx stalling problem
 

Sounds like you are on the right path, but if your engine still will not rev over 2000 rpm, you probably need to go a little deeper. Many carbs have a screen behind the fuel connection to the carb or an internal fuel filter(besides your fuel water separator). That simply be mucked up and need replacing or cleaning. I would reinstall the missing fuel/water separator before doing much else or you will plug up the system again.

Happy Boating
Dan

Re: 4.3 lx stalling problem
 

Thanks Dan, I am trying to get ahold of the original owner to see why they bypassed the fuel/water separator in the first place. It will rev over 2k with a normal throw, however I dont know what it will do under load. I had it up at 4k on a normal pull. Im afraid to put it on the water right now to test it. I guess I'll go grab some tubing and a new filter then order a rebuild kit. Just wondering if some fuel treatment could possibly fix it or if I should stay away from it.

Re: 4.3 lx stalling problem
 

Seafoam brand fuel treatment, B-12 Chemtool(not the spray can) and most other fuel treatments are meant to remove "varnish" and other small deposits in the fuel system and carb. They are not designed to remove trash in jets or a plugged filter. They won't hurt and can help to maintain a clean fuel system. Check to see if your boat has another screen/filter in the carb itself first, if it does and it is a screen u might can clean it, if it has a filter that can be changed, replace it. Also reinstall the fuel/water separator. I would do this before doing anything else or having the carb rebuilt. An easy way to check the accelerator pump is to start the engine and then turn it off, remove the flame arrestor from the carb, look into the throat of the carb(u may need a flashlight), and while u observe have a friend quickly advance the throttle a couple of times, u should see and hear fuel squirting into the throat of the carb, if not the pump is bad. The accel pump only helps on takeoff or rapidly increasing rpm though, not when cruising. One thing I forgot to mention is that in the fuel tank itself the fuel pickup tube should have a course screen that can get plugged with large debris it works like a pre-filter but that is a little harder to get to. Also be patient and don't get tunnel vision, there are a few other things that can cause the same symptoms, low fuel pressure from the fuel pump, ignition timing that is not advancing, etc. Not trying to confuse u even more, just reminding u to keep an open mind and do things one at a time. Sounds like you are on the right track. Usually the problem is simple like a plugged fuel system so make sure that is functioning right first. Keep me posted to how it is going.
Happy Boating
Dan

Re: 4.3 lx stalling problem
 

will do Dan! Thanks for the info. I will try to see if there is a filter in the carb. Is it ok to pull the carb off to have a better look or will I need a new gasket? I know what you mean about the tunnel vision, I keep going back and forth from the fuel pump to the carb and its driving me crazy. If they were cheaper i'd just order both and be done with it. I've got the filters on the way. Thanks again Dan.

Re: 4.3 lx stalling problem
 

You can pull the carb off if u want, the gasket...personally I would replace it since gaskets are fairly cheap. There are a lot of linkage pieces on the carb and probably a couple of cam activated switches on your linkage that if reinstalled wrong can give you fits. If you are not absolutely confident about doing this, get yourself a good manual on it. Carbs are precision devices and need to be treated as such. Good luck and let me know how things are going.

Happy Boating
Dan

Re: 4.3 lx stalling problem
 

Update! I got a new filter and reinstalled the fuel/water separator..... Still the same problem. I also added a bottle of seafoam to it before putting the filter back on. I had the wife give it some gas while I looked down the carb and when she did the only gas I could see spraying was out of one barrel closest to the driver. Not sure if thats normal or not. So i've decided to just rebuild the carb. I keep reading about a rebuild kit thats for an S10 that will work with these and is only 1/3 the price! Does anyone happen to know about this and the part number.

Thanks TJ

Re: 4.3 lx stalling problem
 

Only one side spraying when throttle is advanced does sound like something is plugged. As far as the S-10 part I know nothing about it. If u pull the carb it may have some numbers on it a auto parts store can cross reference. Good luck

Happy Boating
Dan

Re: 4.3 lx stalling problem
 

Hey Dan, do you know if I have to remove the center post to separate the carb? I just see 9 screws that hold it on and then there is the center post that the cover and arrester bolt to. The damn thing wont come apart and I dont want to pry it. cant find a manual or good diagram anywhere.....