Currently underway with a leaky carb. Please help!

[OrangeCrush]

Hey all,

I'm twenty miles off Boston, a week into my summer voyage from Brooklyn to Maine and back on my 1978 Pearson 26, and I've noticed an issue with my outboard motor, a 2002 Mercury 15 hp 2-stroke. I'm hoping some of you might be able to give me some pointers.

I've been using the motor a lot and it's been running great, but I just noticed that the carburetor is dripping fuel while running. Maybe one drip per three seconds. It's hard to tell, but it seems to be originating at the piece on the side of carb itself, where the blue button is that the choke presses down on when pulled out. I had a small fuel leak before, but I thought I'd gotten rid of it when I replaced the fuel filter and related hoses. Those all now seem to be fine. The motor still runs fine, just a little smell of gas when throttling down and it occasionally dies if idling too long.

I'm gonna be in Boston for two days and I'd like to fix this if I can. I'm hoping there are some things I can try without attempting an actual carb rebuild. I've never done that before, I'll be working at the docks and I don't have a ton of time, so any troubleshooting tips would be much appreciated.

Should I adjust the needle and/or float? Clean the carburetor? Is it likely to be causing any other imminent problems right now other than polluting/wasting fuel? Is there anything else I can tighten or adjust?

I have a repair manual for the motor, but my worst case scenario would be getting the carburetor apart and not being able to get it running well again afterwards. So I'm hoping you guys can tell me what the best thing to try first would be.

After Boston I'm heading offshore bound for Maine, and I really need that motor to be reliable.

Thanks a lot for the help!

Jack

[youmeandthed]

sometimes when the needle isn't creating a seal, the carb will leak. pull it out spray some carb cleaner down the holes, visually inspect the needle, and put it back very carefully. When the needle is sealing and you blow in the gas intake no air should go through. If air goes through, you need a new needle. This will cause the gas to always flow into the bowl, and leak.

[OrangeCrush]

Thanks for the reply.

If I take the needle out to inspect it, what are the chances that the gaskets are all toast and I can't get it back together without new parts? I would need to get them shipped to the marina in Boston, which could take a while and be expensive. If thats what it has to be I'll do it, of course. Do you think this is a hard job to do dockside?

Alternatively, if I leave it for now, is it likely to get worse or cause other problems? Is there a chance I could get away waiting until I get back to New York to fix this? As I said, I'm really nervous about messing up what is still a fully functional motor...

Thanks again.

[youmeandthed]

don't worry about the gaskets, they are just pieces of wax paper, if they are really messed head down to store and pic up some gasket material. They are not high pressure gaskets so you will most likely be ok. I have taken off my carb on my little honda generator on the boat many times and way further away from parts than your situation. If you put it back together as you took it apart it will act the same. I think you might have some gunk obstructing the needle seal, it happens a lot. You have the internet so try to pull up a a diagram, carbs are actually quite simple things.

Most importantly, do what makes you feel most comfortable, if you don't mind leaking a little gas, no worries. Deal with it when you get back.

[perchance]

The chances of ruining the gaskets is pretty likely but you sometimes get lucky if they haven't been in place too long. Even if they are intact when you disassemble the carb they tend to be compressed and need some type of sealant to be reused. as far as the leak is concerned the fire risk should not be ignored nor the fact that gasoline is being discharged in a marine environment.
Rebuilding a carb is fairly straightforward if you have the tools and follow the manual.

[OrangeCrush]

This is a tough one.

Fire danger and polluting definitely worry me, but I'm also very concerned that I just won't be able to get it running right if I rebuild the carb myself at the dock. Will I need any specialized tools? A pan for catching/soaking in carb cleaner, compressed air, Socket set, screwdrivers... Anything else I'm overlooking? Is tuning the motor after installation difficult? The manual says it's 'moderate' difficultly, but that's also what it said about my fuel pump overhaul and I ended up botching that one and taking it to the shop.

To be more specific on the leak, it's coming from the seal in the primer system and the little vent hole on its side. I don't suppose just tightening the four screws holding the primer system together would help?

I'm leaning towards running the motor as it is until I can schedule a mechanic to do it for me somewhere along the way.

[perchance]

If you are one of those unfortunate people with two left hands then perhaps it is best left to the technicians. You might want to consider taking a small engine/outboard course at a local community college. At some point in your boating life you will be forced to to get your hands dirty to get home so best prepare now.

[noelex 77]

Taking the carb off is usually simple on the 2 stroke outboards.
My smaller 4 HP Yamaha regularly ( about every 6 months) clogs up the carb jet or more commonly the little needle valve that lets fuel in. It now only takes 45 mins to take it off disassemble the carb clean it and put it back together.

If you can identify where it's leaking before you remove the carb it will help, but the leak is probably very easy to fix say just tightening up the fuel bowl or drain plug.The gaskets usually survive, but you can make new ones easily.

A lot of crusing sailors are good at fixing outboard problems. If you can find any ask for help.

Dripping fuel is not good. I would fix it now. It will give you the confidence to do repairs in the future.