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-   -   Carb Problem 351 Holley 4160 Flooding (http://www.mastercraft.com/teamtalk/showthread.php?t=49298)

SugarLake 07-13-2012 04:45 PM

Carb Problem 351 Holley 4160 Flooding
 
Getting frustrated and looking for ideas. Boat is an '88 PS 190 with 351 and brand new (last year) Holley 4160. Boat was running fine but I decided to replace the power valve with a 2.5 because I wasn't sure what the new carb came with and I was having some slight bogging and rich smell out of the hole. Pulled the front bowl, switched out the power valve, put it back together and it wouldn't start. Finally figured out it was getting way too much gas and got it to start with choke open and wide open throttle. If I back off the throttle it will stay running for a while (with black smoke) but quickly loads up.

I pulled the front bowl again, blew through the float and it seemed to be shutting off fine. Tried again with same results. Then I pulled both bowls, blew through the inlets with compressed air, checked them both to see that the needles and seat were closing by holding them upside down and blowing through the inlets with my mouth. Seemed to be working fine. Put it back together and still have the issue. I also tried changing back to the original power valve.

What did I do? Doesn't make any sense to me.

mcparadise 07-13-2012 05:18 PM

Quote:

Originally Posted by SugarLake (Post 858010)
Getting frustrated and looking for ideas. Boat is an '88 PS 190 with 351 and brand new (last year) Holley 4160. Boat was running fine but I decided to replace the power valve with a 2.5 because I wasn't sure what the new carb came with and I was having some slight bogging and rich smell out of the hole. Pulled the front bowl, switched out the power valve, put it back together and it wouldn't start. Finally figured out it was getting way too much gas and got it to start with choke open and wide open throttle. If I back off the throttle it will stay running for a while (with black smoke) but quickly loads up.

I pulled the front bowl again, blew through the float and it seemed to be shutting off fine. Tried again with same results. Then I pulled both bowls, blew through the inlets with compressed air, checked them both to see that the needles and seat were closing by holding them upside down and blowing through the inlets with my mouth. Seemed to be working fine. Put it back together and still have the issue. I also tried changing back to the original power valve.

What did I do? Doesn't make any sense to me.

For what it my be worth, I had a "similar" problem in my 98 regular-carbed SS19 with Indmar 305that kicked my mechanic's butt. Nothing worked. Holly 4160 650 cfm was fine and almost new....end of story is the Carter fuel pump (high volume low pressure) was putting out way too much pressure and flooding her out. At that time I had no pressure gage, no longer though !, so it was hard to disgnose. I went with the marine Holly instead which mounts with terminals on top not on bottom (poor Carter design in my book considering they are "press fit" with a screwy wire retainer).

SugarLake 07-13-2012 11:52 PM

Thanks, I think a fuel pump is worth a shot. Mine is original so it wouldn't hurt to replace it at any rate. I've had the bowls off about 5 times now. Took out the floats and needle and seat, can't see anything wrong. No fuel coming out of the J tubes either. It really has me stumped.

SeaCup 07-14-2012 12:43 AM

Since the boat was running fine before you changed the power valve I would double check the valve. The valve might be defective or leaking around the gasket because it was not tightened properly. Use a little petroleum jelly and hold it upside down when you tighten it to make sure the gasket stays centered.

Super easy to test the valve, screw in both your idle air screws (count how many turns so you can put them back where they were) and if the engine starts to stumble and die the valve is good. If it keeps running the valve is bad. :D

SugarLake 07-14-2012 09:10 PM

It was the metering block gasket. When I pulled it off the first time it tore a little so I replaced with one I had got before and never used. Apparently there are 2 different ones for the 4160 and I used the wrong one. I got a kit at the MC dealer today and it came with 2 different ones.

BUT with all my screwing around trying to figure it out I think I messed a few things up. The boat is running great, but I have the mixture screws all the way in. If I turn them out the RPM's go down. Maybe the float is too high? Any ideas appreciated.

Cloaked 07-14-2012 10:32 PM

Quote:

Originally Posted by SugarLake (Post 858292)
It was the metering block gasket. When I pulled it off the first time it tore a little so I replaced with one I had got before and never used. Apparently there are 2 different ones for the 4160 and I used the wrong one. I got a kit at the MC dealer today and it came with 2 different ones.

BUT with all my screwing around trying to figure it out I think I messed a few things up. The boat is running great, but I have the mixture screws all the way in. If I turn them out the RPM's go down. Maybe the float is too high? Any ideas appreciated.

Begin with them all the way in, turning each one out approx. 1 - 1-1/2 turn. That should get you very close. If that isn't feasible, you have another issue. Patience. The 4160s are cantankerous but once you learn the characteristics, they work just fine (for the most part).

Make sure the electric choke is adjusted properly. Typically, mid-range on the scale will get it very close. Powervalve can also trick you, so just make sure it's seated properly and is in good working condition.

Have a double-check look-see here ==> http://www.holley.com/data/Products/...l/199R8339.pdf

.

SugarLake 07-15-2012 01:24 AM

Quote:

Originally Posted by Cloaked (Post 858315)
Begin with them all the way in, turning each one out approx. 1 - 1-1/2 turn. That should get you very close. If that isn't feasible, you have another issue. Patience. The 4160s are cantankerous but once you learn the characteristics, they work just fine (for the most part).

Make sure the electric choke is adjusted properly. Typically, mid-range on the scale will get it very close. Powervalve can also trick you, so just make sure it's seated properly and is in good working condition.

Have a double-check look-see here ==> http://www.holley.com/data/Products/...l/199R8339.pdf

.

Yeah, I know the drill with the mixture screws. I started with them out 1 1/4. Turning them out made it worse, so I tried turning them in and it smoothed out and was best when they were in all the way. I know that shouldn't be the case but the boat is actually running pretty good. The idle circuit must be getting too much fuel but I don't know why. My only theory at this point is the fuel level in the bowl is too high, but I'm not sure about that.

Thanks for the link. Those are the same instructions I have that came with the kit. The frustrating thing about them is in the section were they instruct you on the level for the non-externally adjustable float, they show you where to measure it but nowhere in the instructions do they tell you what the measurement should be!! On the skidim site they reccomend setting them level ( parrallel) but that is way too high. I found I had to set the secondary float way down from that or else I had gas pouring out of the venturis. If anyone knows the measurement for the MARINE 4160 float level that would really help. I can't seem to find it anywhere.

Cloaked 07-15-2012 07:21 AM

Quote:

Originally Posted by SugarLake (Post 858343)
Yeah, I know the drill with the mixture screws. I started with them out 1 1/4. Turning them out made it worse, so I tried turning them in and it smoothed out and was best when they were in all the way. I know that shouldn't be the case but the boat is actually running pretty good. The idle circuit must be getting too much fuel but I don't know why. My only theory at this point is the fuel level in the bowl is too high, but I'm not sure about that.

Thanks for the link. Those are the same instructions I have that came with the kit. The frustrating thing about them is in the section were they instruct you on the level for the non-externally adjustable float, they show you where to measure it but nowhere in the instructions do they tell you what the measurement should be!! On the skidim site they reccomend setting them level ( parrallel) but that is way too high. I found I had to set the secondary float way down from that or else I had gas pouring out of the venturis. If anyone knows the measurement for the MARINE 4160 float level that would really help. I can't seem to find it anywhere.

Here's another link for some ideas that may ring a bell for you.

http://www.correctcraftfan.com/forum...float-settings

.

thatsmrmastercraft 07-16-2012 03:17 PM

The relationship between mixture screws and idle speed screw needs to be proper. If the mixture screws are in too far, you can make the carb idle on the main metering circuit - though not very nicely. As Cloaked said, start with the idle mixture screws 1 1/2 turns out and get you idle speed set properly.

If the diaphragm on your power valve (and it should be 2.5) is ruptured, it will run full rich and give you black smoke coming out the exhaust. The only true way to test it is to remove it and hold the outer diameter of it while trying to gently twist the pointy end. If it turns freely it is bad. By turning your mixture screws in all the way, the engine can still run if there is a significant base gasket leak.

pkskier 07-17-2012 09:25 AM

If the power valve gasket is not properly set it will allow fuel to leak by and the engine will idle with the mixture screws all the way in. Check the power valve gasket.


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