Carburetor or fuel pump?

[dkelly4819]

Boat ran perfectly 2 weeks ago, then last week was very difficult to start, idled rough, and died out each time I put it into gear. I thought it was a fuel pump issue, but my marina took it to the shop and just called me saying it was the carburetor. They want to sell me a carb from Napa that isn't a marine unit, but supposedly will bolt right on. I'm not sure I want to go with a non-marine piece, and can't the carb be re-built? How hard is that? I've been on skidim and they sell rebuild kits, and also new Holleys, although they are a couple hundred more than the Napa unit. I figure they has got to be a difference, thus the price difference. Thoughts? Boat is an '89 Sunsport, PCM 351.

[wotan2525]

Rebuild it. You can order the kit from amazon. It's not hard to do. Get a couple of cans of aerosol carb cleaner and follow the directions.

[dkelly4819]

Wotan - Thanks for the input. Can a carb just stop working correctly from one day to the next? What goes bad in them?

[UKandH]

Carbs are notoriously fickle. The one thing i would add to the process above is to pay to get the stripped carb ultrasonic cleaned. It makes the world of difference and gets rid of every bit of dirt and gummed in fuel. I did mine and its been 100% since.

[leetudor]

If you buy a new one, DO NOT USE THE AUTOMOTIVE ONE, use marine.

[Moor]

If you use ethanol gas, that is more than likely your problem. In as little time as a week sitting, the ethanol starts to break down and gel up inside the float bowels of the carb. They you start the engine and the gel gets sucked up into the jets and all the other little ports and passages in your carb, clogging them up, causing a poor running condition. Buy a rebuild kit and rebuild it yourself. Its not very difficult, and can be done in an afternoon or less, depending on your skill level. I've been dealing with ethanol gas causing problems with carburated engines for years, in everything from my weed whacker, to my muscle car and my boat. every year i remove the carbs, disassemble, clean and reassemble. im usually disgusted at all the jelly inside the carbs. even if its not an ethanol issue in your carb, it definitely sounds like a carburetor problem over a fuel pump.

Interestingly enough, my boat has been the one carb'ed engine that doesnt suffer from the ethanol problem anywhere near as much as my other carb'ed engines. I Think its because my boat sits in the water most of the season, and the daily waves that rock the boat back and forth are just enough to keep the ethanol from turning to gel. The gas station down the road just started carrying ethanol free 91 octane, so now i put that in everything i own.

[DKJBama92Mariah]

Echoing the above. DO NOT USE AN AUTOMOTIVE CARBURETOR. If you feel like you must replace it, the correct carb is Holley list # 80319-1. It's available from Summit Racing for for few bucks cheaper than skidim. Sounds like your idle passages may be plugged with gunk. For the $580 a new carb costs, I'd certainly try a rebuild first. The key is a complete teardown, lots of spray carb cleaner, and compressed air to blow out all the gunk in the tiny fuel and air passages in the idle circuits. If you have a local speed shop nearby, I'd ask them for a recommendation on a rebuilder and bring the carb and the correct kit to him. When you order the kit, also order TWO new carb base gaskets; one for between the intake manifold and the PCV spacer and another for between the spacer and the carb.

If a marine service facility offered to install an automotive carb on my boat, they would be fired immediately for incompetence. I can understand it when a do-it-yourselfer doesn't know any better and wants to save a few bucks on a new carb. However, I am just BLOWN AWAY that a supposed professional marine service provider would offer to stick an auto carb on your boat. They are either incompetent or simply don't care.

[loopmaster]

Great replies on this. Holly Carbs are easy to work with, rebuilds are straight forward as well, and just cleaning it is worth while and takes less than a hour. We use Sea Foam gas treatment to help the poor gas we have now. We also do not buy it on the lakes, we have had many times the gas is really bad found on the lakes, sets too long for one thing. I clean my carb each season and rebuild every two years and have had my 90 Sunsport from new.

[jasun]

I'm a fan of edelbrock. I had a Holley but my timing was off so it wasn't its fault but the first time it back fires through the carb you more then likely have to replace the power valve. I feel if you replace (which I would rebuild it first) I would change it out for an edelbrock. Just my 2cents

[dkelly4819]

Thanks for all the input. I'm heading to Carburetor Specialists in Alpharetta this morning to see about rebuilding this one. Their name came up from a couple friends on the lake who've used them in the past. If it doesn't make sense, I'll head down to Summit in McDonough to pick up a new one from them.

[DKJBama92Mariah]

I'm a fan of edelbrock. I had a Holley but my timing was off so it wasn't its fault but the first time it back fires through the carb you more then likely have to replace the power valve. I feel if you replace (which I would rebuild it first) I would change it out for an edelbrock. Just my 2cents

This old issue has been addressed since 1992. http://www.enginebuildermag.com/2013/01/the-truth-about-power-valves-used-with-holley-carburetors/

For carbs older than that Holley offers a retrofit kit to protect the power valve. https://www.holley.com/products/fuel_systems/carburetor_components/power_valves/parts/125-500

If you have your old carb rebuilt, having this retrofit done wouldn't be a bad idea.

[dkelly4819]

Carburetor Specialists looked it over and said it was definitely still in good shape and worth rebuilding, so I left it with them and they said I'll have it back no later than Friday, so, fingers crossed, I'll be back on the water this weekend! Also, a whole lot cheaper than buying a new one.

[frmdog]

Keep us posted I'm having the same issue but my coil gets really hot for some reason too. How much did it cost to have it rebuilt if you don't mind me asking

[dkelly4819]

frmdog - It cost me $399.00 for the rebuild. I know, its expensive but I asked around some guys on the lake and they told me Holleys can be tricky to rebuild, especially since I have no experience doing so. It comes with a one year warranty, which is at most what I would have gotten with a new one, but cost about $200.00 less than a new one, so I thought it was my best option. It was waiting on the doorstep for me when I got home today, so hopefully I'll be back in business this weekend. Not that it really matters, but from a visual inspection standpoint, they did a fantastic job. It looks brand new.

[dkelly4819]

The carb was reinstalled Friday and the boat ran like a champ all weekend! Great to be back on the water, and glad it wasn't something more serious.