1990 Four Winns Candia 4.3 OMC Cobra- Fuel Issues

[candiaoh]

I have a 1990 Four Winns Candia 180, powered by a 4.3 OMC Cobra. Its been a little over a year since it last was run. Bringing it back to life, going to have the outdrive serviced (new bellows and shift cable plus any other standard service) It had about 5 gallons of gas in the tank. I added 5 more and treated both with seaform (roughly 1oz per gallon). Put the muffs on, started it on third try and ran for about 20 mins- it had reached operating temp and running smooth. Then engine started to stumble. Stalled a couple times and restarted til eventually it would not start. It would try with carb cleaner but could not maintain it.

Except to my small engines, I don't have a lot of familiarity with a carbureted engine. My initial thought was a dirty carb but after doing research here I am thinking its a fuel delivery issue. I would like to go ahead and change the fuel filter and separator. Which brings me to my question...where is the fuel filter??? I understand there is a screen near the carburetor, but its there another filter as well? Is it inline or is it in the gas tank?

This may or may not solve my issue but I feel like its a good place to start..,.also planning to change oil, filter and belts.

 

[HT32BSX115]

Howdy,



It would help if you post your model number. The boat year model is frequently NOT the same as the engine and drive.

Go to http://epc.brp.com to view the 4 1990 models and the 4 1989 model part illustrations.

Your filter is likely a "spin-on" type and you can buy it right here on iBoats, NAPA, West marine or other marine parts stores etc...

Year old fuel would probably be ok if it was diluted with an equal amount of fresh fuel. I would not use Seafoam or other alcohol/naptha/mineral oil snake oil. adding it after the fact (a year later) does nothing to your cause.

You likely have either have a clogged fuel filter, failed fuel pump, stuck/clogged anti-siphon valve, clogged fuel pickup screen or clogged fuel vent. Some carburetors have an integral fuel filterscreen. Yours could be a 2 or 4bbl based on your model year and number. (8 different models over 1989/1990 could be in your boat)

You need a service manual. They cover specific models and years. Go to http://boatinfo.no/lib/omc/manuals/1986-1998omcmanual.html#/0 for an online manual but it would be good for you to get the correct OEM manual for your model. I see them on craigslist and ebay once in a while. Seloc and Clymer are not all that good.

In general, before posting, it's always good to have a look at the following thread.......... read #1 first!
http://forums.iboats.com/forum/engi...69-must-have-technical-information-for-diyers

Regards,



Rick

 

[candiaoh]

Thanks, Rick.

I really hate to sound like I'm clueless- I am actually a half way decent shade tree mechanic- but marine/ carbureted engines are just areas I have not dealt with much before.

How do I determine the actual model number? Is it stamped somewhere on the engine or the drive?

I think I am going to start with the low hanging fruit, changing the filter, cleaning the screen and checking for fuel delivery. Also, I will change the plugs and potentially the wires (just did points and dizzy cap 2 years ago).

 

[HT32BSX115]

Thanks, Rick.

I really hate to sound like I'm clueless- I am actually a half way decent shade tree mechanic- but marine/ carbureted engines are just areas I have not dealt with much before.

How do I determine the actual model number? Is it stamped somewhere on the engine or the drive?

I think I am going to start with the low hanging fruit, changing the filter, cleaning the screen and checking for fuel delivery. Also, I will change the plugs and potentially the wires (just did points and dizzy cap 2 years ago).

Well, we were all there at some point!

The model number should be up on the engine. That service manual link should indicate a location.

Understand that in the last 25 years, someone could have changed nearly everything including the engine block and accessories.

If you cannot find the model number, just pick one of the diagrams that matches your engine closest. there's not a huge difference between 4bbl carbs in that year. Many carbs have a small filter right where the fuel line connects to it. That iBoats thread I posted has a LOT of good places to check for fuel delivery and other problems.

Cheers,


Rick

 

[candiaoh]

Thanks again. I will tell you I know for sure its a 2 barrel carb if that helps...probably narrows things down to two models I'd imagine.

 

[candiaoh]

UPDATE: I replaced the fuel filter/separator. When I dumped it out, the fuel had a very yellowish color. I also checked the screen going into the carb and it was clear. Lastly, I verified fuel delivery by removing the fuel line at the carb and turning it over once- fuel came out the fuel line. I added starting fluid and the engine fired and ran for a second and then died. At this point should I assume bad gas and or gummed up carb? If I empty the fuel from the tank, is there a way to empty the bowl without removing the carb in order to get fresh gas running through the system?

 

[HT32BSX115]

UPDATE: I replaced the fuel filter/separator. When I dumped it out, the fuel had a very yellowish color. I also checked the screen going into the carb and it was clear. Lastly, I verified fuel delivery by removing the fuel line at the carb and turning it over once- fuel came out the fuel line. I added starting fluid and the engine fired and ran for a second and then died. At this point should I assume bad gas and or gummed up carb? If I empty the fuel from the tank, is there a way to empty the bowl without removing the carb in order to get fresh gas running through the system?

Sounds like the fuel might be a little older than a year maybe? .............. regardless, you probably need to purge all the fuel from the system and get the fuel out of the carb. There's no drain on the carb, so you would have to remove the top "plate" on the carb and suction out the fuel using a piece of hose and turkey baster (get a cheapo-baster at Walmart etc......)

Taking the top cover off the carb will allow you to look in the float chamber and see if the float-valve is stuck or there's "crud", water , etc, in the chamber.

All this is leading up to a carb rebuild of course because you can damage the carb gaskets when you pull it apart.

Probably wouldn't be a bad idea to have a carb repair kit on hand. Once you get it apart, it's not a bad idea to replace the needle/seat, etc.(it's all in the kit)

Some other things to check with the carb: Before starting the engine, going from idle to full throttle (have a helper do this) do you see a good "squirt" of fuel into the carb from the accelerator pump? With the engine NOT running, is the choke 'butterfly' CLOSED? (can you open it)

Every time you move the throttle from idle to wide open, the pump should squirt a (steady) shot of fuel into the venturi's If it doesn't, the float valve may be stuck shut (or the accel-pump might be "bad").

If it is "squirting", You might be able to pump it until the bowl is empty, and then re-connect the fuel lines to refill the carb with fresh fuel. You will squirt that fuel into the intake which will end up in the cyls. And in turn could foul the plugs and/or wash past the rings to end up in the oil.

We're not talking about a LOT of fuel, and it really won't hurt anything.........that 1/4 cup or so of fuel in the oil will simply evaporate quickly once the engine warms up. .........just pull the plugs and crank the engine to blow most of it out. (have a fire extinguisher handy!)

Once you get it started, any residual fuel will be quickly expelled.

Cheers,


Rick

 

[candiaoh]

Just to update. The problem ended-up being a dirty carb...apparently a spider had moved in and it remnants ended-up clogging things up. I have also removed all the old fuel and will fill-up with fresh stuff. Going to have the bellows and shift cable done next week.

What did they say about a boat being a hole in the water you throw your money in.....?

 

[HT32BSX115]

J
What did they say about a boat being a hole in the water you throw your money in.....?

Glad you found the problem!!

Welcome to OUR world!!