Saltare,454 is Idling rough, doesn't stay running.

[ruby23m]

Past few times out on the Saltare she has been running rough at idle, pulsing is the best way to describe from
400-1000 RPM when its warmed up, not cold. Usually just kills when put into gear. Oil was a bit low, had to add 1.5 quarts, but I don't have much of a reason to think thats the problem. Oil pressure was fine, temp fine as well. As a temporary fix to stay running I adjusted the throttle cable to achieve 1000rpm at idle, but still pulsing. I know the engine hasn't had a tune up in at least 3 years, this is my third summer owning the boat and my first issue concerning how it runs, Please HeLP!

[skiman_61]

Check the timing and other than that it sounds like you need a tune up. Replace the distributor cap, get rid of the points if you still have them and go with a condenser free ignition. New wire and plugs you'll be in good shape. Mine is an '87 454. Mallory distributor and a Holly carb.

[wotan2525]

I agree. A tune-up is a good place to start. You may be experiencing a carb or a fuel issue, as well -- but let's get the electrical in order, first.

I'd also change your fuel filter, top off with good gas and make sure the electric choke is functioning.

[michael hunter]

If it was ignition it would act up cold as well. Sounds like a blown power valve. I would start with a carb overhaul.

[rludtke]

If it was ignition it would act up cold as well. Sounds like a blown power valve. I would start with a carb overhaul.

I agree. Have you ever experienced a back-fire? The Powervalves on some, possibly all Holley 4160 carburators can be damaged by backfires. Wether you have or haven't, a carb overhaul would be my first action.

[ruby23m]

No backfires to speak of. I'm nearly clueless about how to work on the 454 and the holley carb being this is my first problem with it, that means time to start learning! What exactly does a carb overhaul entail?

[rludtke]

The Holley 4160 is quite simple really. The overhaul kit replaces all of the components subject to common wear. The fuel carries a lot of micro-abrasives in it, and it wears out parts. Some of these parts are very sensitive to this wear, so overhauling a carberator is actually a necisary routine maintenance requirement.

Essentially, you will remove the float bowls and replace the needle and seat assemblies, the accelerator pump, the power valve, and a number of gaskets and seals. The exploded view diagram linked below will help. Keep track of what you remove, and replace the parts you remove that have new versions in the kit. The kit will include more parts than you need, so don't freek when you have parts left over in the kit. The metering block comes off to access the power valve. After removing the bowl bolts, they are only held on by the gaskets. They may not come off without a little effort. Be sure to clean away any remnant gasket material.

By a can of carb cleaner from the auto parts store, and use it to soak the parts that you remove (and do not replace), as well as the throttle bores of the carb. Rinse with hot water, and let dry, or blow dry if you have a compressor. Careful though, many of the parts are small.

Oh, and be extra careful with the clips that hold the floats on the shaft, they are tiny, and they seem to want to fly.

This is your carburator: http://holley.com/0-80319-1.asp
This is the overhaul kit: http://holley.com/703-47.asp
This is Holley's technical library: http://holley.com/TechService/Library.asp
This is an exploded view of the 4160: http://holley.com/data/TechService/T...ded%20View.pdf
This is the float adjustment procedure for the 4160 (follow the Duracon (plastic) procedure): http://holley.com/data/TechService/T...ded%20View.pdf


The rebuild is actually very intuitive, you shouldn't have any trouble. The overhaul kit commonly retails for about $50-$75 at NAPA or other mainstream retailers. I have found them for $25 on Ebay stores.

Good luck,

[wotan2525]

Rick -- This might be a dumb question, but can you rebuild these without removing them from the intake manifold?

[scottchapin]

Great post and links, doing mine Sunday. Thanks

[rludtke]

Rick -- This might be a dumb question, but can you rebuild these without removing them from the intake manifold?

Yes. I bucket carb overhauls into three categories: 1) simple parts swap, 2) Complete disassembly, clean, replace parts 3) Complete disassembly, clean, replace parts, and restore shafts and bushings to tolerances, etc etc.

A simple parts swap can be done in the boat, on the water (i've done this many, many times). You do not need to disassemble beyond the bowls and metering block to replace the parts that come in the overhaul kit. These carburators do not have external float level adjustmers, so I have had to open the bowls repeatedly out on the water to fine tune my float levels.

If performing the simple parts swap procedure on the boat, carry an old plastic water bottle with a sealable cap to capture the fuel drained from the bowl. Carry some paper towels to stuff below the carb to capture anything missed by the bottle. You will spill a little fuel, but try to minimize this the best you can. Drain the fuel out of one of the lower float bowl bolt holes. When you remove the bolt, fuel will pour...

If you spill some fuel into the bilge, wipe it up, and be sure to give the boat some time with the engine cover open to ventilate.

The barrels and butterflies are an area that gets dirty, and could benefit from the cleaning. For this you would have to remove the carb.

The butterfly shafts and bushings wear (feel for exsessive side to side or up and down shaft play). When worn enough, un-metered air can leak through, generating a leaner mixture. The shafts and bushings are purchaseable and replaceable. For this, removal of the carb would be neccisary.