New Metering Block- not running

I'm in need of some help with my carb. Started having problems late this summer with the boat not wanting to idle below 1200 rpms, but ran perfectly fine otherwise. I had replaced my secondary fuel bowl in the beginning of the summer (because it was disintegrating--literally could flake chunks of material off of it) so I figured the same thing was happening on the primary side of the carb. Took the primary bowl off, and it looked fine, but the metering block was flaking apart. Here's a pic:



I ordered a new metering block from skidim thinking this would be a quick fix, but the boat will absolutely not idle now. It's terribly hard to get started, and then when I could get it to start, I had to have the throttle 3/4 open to get it stay running around 1000-1500 rpms, and it was real rough at that.

The old and new metering block have all the same markings, so I'm sure it's the correct part. The only thing I noticed different was the powevalve on the new metering block felt stiffer, but I tried running it with the new powervalve and the old powervalve and noticed zero difference. I also tried numerous adjustments with the idle mixture screws with no noticeable difference.

Any help or advice would be greatly appreciated. I mess around with 2 stroke jet skis a lot and this is the first automotive style carb that I've personally messed with, so I'm over my head as it is.

Thanks for the link, a lot of good info there. I'll double check the float levels. I did spray carb cleaner through all the main body passageways before I reassembled with the new metering block. Those appeared to be clear.

I think I'll probably pull the carb body off the base next, try and spray cleaner through those passages, and go from there.

Disagree with Pete, the only time I've dipped the carb, it removed the gold Holley coating. Rendered the carb junk. I've done plenty of rebuilds with the spray, gotta follow it up with compressed air. Gotta confirm each passage is clear before moving on but that is good practice anyways.

SNobsessed wrote: If the zinc flakes are causing a restriction in the passages, carb cleaner will not dissolve them. Maybe the carb body is disintergrating too. Sounds like time new for a quick fuel carb.

So I also thought that might be a possibility, but now I have over $100 in this carb between the secondary bowl, metering block, and the rebuild kit, which bought it in the beginning of the summer when I saw the condition of the secondary bowl.

Regarding the dip vs. spray, I'll probably just try spray cleaner first, since it's what I have in my garage. If it appears that passages are still blocked after spraying then I'll order the Berryman.

The thing that really has me stumped about this though is that the boat ran perfectly fine (other than not truly idling) with the old metering block, and now barely even runs with new metering block. I suppose it's possible that more flow through the new block dislodged and lodged some material somewhere else in the carb though. I don't know.

On a side note, is this a normal for an oldish marine carb?

Bri892001 wrote: From Skidim: "This is a New style metering block that will not fit older Holley 4160 carbs. It no longer has the tube & O-ring and is used on List # 75009-3 and 75009-4." Agree with Snobsessed, it's time for a new carb, no sense throwing good money after bad.

Regarding the tube & o-ring, I apparently do not have the original carb on my boat, it has the 75009-3 list #. Actually talked to skidim about this before purchasing.

I did pull the new metering block though and inspected it a little bit. Found a couple of the passageways are not perfectly round, like the ones on the old block are. Not sure if that's enough to cause problems..

Hmmm, the only other thing I can think of.

Did the new metering block come totally naked? In other words, did it come with the idle mixture screws, and associated gasket (or whatever the replaceable piece the mixture screw screws into is called) installed? Or not? If not, did you transfer it over correctly from the old one, or use a new one?

Yea, the idle mixture screws were already installed, but I didn't realize there was a replaceable piece that the screws were installed into. That might be something worth inspecting on the new metering block.

The needle in the float bowl does move freely.