New Carb Issue

[BigDaddyPJS]

Installed a new holley 4160 Carb on my 1992 Four Winns 200 Horizon. My boat is powered by a OMC Ford 5.8L (351) with a King Cobra outdrive.

After installing the carb, gave the boat a few turns and started her up. Checked for fuel leaks, put the tools away and left the dock. When I got out in the open water I gave the boat some gas. As soon as the boat hits 1200 rpm, she would stall. I started the boat up and tried it again with the same results. Went through the this a few more time and idles back to the dock. Ran the boat in neutral at the dock up to 2000 rpm's with no problem. The stall at 1200 rpm only happens under load.

The reason I replaced the old carburator was I have been having a problem with the boat at idle. The boat would stumble and shake at idle. At high rpm's the boat would run fine. The boat at WOT would run at 4300 rpm's with no problems. I ran the boat during the 4th of July weekend with no issues other than the idle. I do not believe I have a any fuel issues from the fuel tank up to the carburator. I have also replaced the water seperator.

My question is this. What do I need to look at with this new carburator? I am going to contact the company I purchased this carb from but would like some sound advise on any adjustment I could possibly try and avoid any down time.

 

[6meter]

Re: New Carb Issue

You have found the problem, just the wrong fix. You could have had the marina rebuilt your old carb for less money than a new one. Something could be wrong with the new carb inside.

 

[Kainon]

Re: New Carb Issue

Is the choke opening fully ?

 

[BigDaddyPJS]

Re: New Carb Issue

Yes the choke is full open. Had a friend watch as I gave her the gas. It dies the same way every time. Give her the gas (fast or slow) and the motor dies at 1200 rpm's. Maybe I bought a new brick and not a new carburator! If I don't get any satisfaction from the company I bought this thing from I am just going to rebuild the old one and call it a "lesson learned".

 

[full stringer]

Re: New Carb Issue

turn both idlle air mixture screws out 1-3/4 turns if not already also the secondaries may not be opening up due to a vacum leak check to make sure all carb end caps are on and tight. other than that you could remove the carb and open the secondary float bowl cover bend the float arm down just a little bit so the float sits just a little bit down from even in bowl now that u have the carb off look for the little hole on the underside base there is a small flathead screw there to adjust the secondary stop and prevent it from sticking u might have to grind or file a flathead screw driver to fit it in there turn the screw until the secondaries close all the way now turn until they just start to open then 1/4 turn more install and set the idle air adjustment further after engine is warmed up

 

[[OBC]Patch]

Re: New Carb Issue

I had similar problem, it was ignition. New cap and rotor fixed the high speed and improved the starting, (with plugs at start of season), and a new carb contributed to improving idling. Your almost there!

 

[zbnutcase]

Re: New Carb Issue

Is it the correct marine carb for the application?

 

[a70eliminator]

Re: New Carb Issue

That 4160 should be good to go right out the box, you have another problem.
Falling off under a load is a classic lack of fuel as in clogged filter or bad fuel pump.

 

[BigDaddyPJS]

Re: New Carb Issue

I sent the carb back to the company I bought it at thier exspense. I contacted them on the phone and they stated the power valve might be to small. They also stated they have had issues with other customer with the same carburator. I placed the old carb back on and I was able to run the engine under load at 4300 rpm. As mentioned before, the engine idle with the old carb is very rough. I do not believe there is anyother issues such as the fuel filter or ignition.