CARB HELP NEWBIE

[tomekrys]

So a week ago or so I go out to my boat and it just won't start. Thinking I got water in the fuel or dirty fuel. Finally get it to start using carb spray but then it won't idle. Have a mechanic look at it and he tells me he backed out both the screws on the carb and either it will clear or I need a rebuild. Questions:

1. Since the carb screws are backed out what will happen if it clears?

2. What do the two screws do? Air and fuel I am assuming.

3. What do you think I can do if this happens to me on the lake?

[Captain Blood]

I would not try and run the boat with both screws backed out all the way. Maybe in the driveway with a fake-a-lake hooked up but not on the water. Too dangerous and it will run like crap.

1. Since the carb screws are backed out what will happen if it clears?

I doubt that anything will clear. It sound like you need to drain the tank, flush the fuel system, change the filter, and take the carb apart for a good cleaning/rebuild.

2. What do the two screws do? Air and fuel I am assuming.

You are correct, they are the air and fuel mixture screws.

3. What do you think I can do if this happens to me on the lake?

I wouldn't take the chance, pull it apart and fix it , or find a good mechanic to do it for you.

You don't want to have a fuel problenm on the water.

Edited June 10, 2006 by Captain Blood

[tomekrys]

I would not try and run the boat with both screws backed out all the way. Maybe in the driveway with a fake-a-lake hooked up but not on the water. Too dangerous and it will run like crap.

1. Since the carb screws are backed out what will happen if it clears?

I doubt that anything will clear. It sound like you need to drain the tank, flush the fuel system, change the filter, and take the carb apart for a good cleaning/rebuild.

2. What do the two screws do? Air and fuel I am assuming.

You are correct, they are the air and fuel mixture screws.

3. What do you think I can do if this happens to me on the lake?

I wouldn't take the chance, pull it apart and fix it , or find a good mechanic to do it for you.

You don't want to have a fuel problenm on the water.

You think that in a week the boat could go from running fine to needing a carb rebuild? I'm just skeptical that something that drastic happened. I haven't looked at exactly where the screws are but I probably need to play with them some to see if they really are backed out or if he was exagerating. There is that carb cleaner stuff and fuel treatment. Maybe those can clear some debris or something that happened. Whats the danger of running with the screws too far out?

[Sunsetter95]

If it was running fine a week or two ago, I would tend to think that some dirt got into the carb, the fuel filter(s) are clogged, or you got some bad gas.

Filters are cheap, replace them first. Dump some fuel out of the filter into a glass jar and look though it and see if you can see any water in it. Be careful!!! Do it out and away from the boat and house. If there is water present, you may want to drain the tank to be safe. If you don't see any, I would add some fuel additive to the tank. It can't hurt.

The screws are air/fuel mixture adjustment screws that affect the idle and very low rpm range operation. They are usually in the front on the carb. You could take them out and spray some Gumout carb cleaner in the holes using the little tube for the spray. First turn them in counting the turns until they go just snug, then take them all of the way out. That and the spray should clean out any gunk, if any, that may be in there. Re-install the screws all the way in seating them just snug again, then back them out ~1 1/2 to 2 full turns if the turn count you did is greater. That should be good enough to get it started and running, as far as adjustment screws go.

I wouldn't run it at the lake with the screws backed out all the way. This will cause the engine to run too rich and foul the plugs and quit again, should you even get it running. I would do all the trouble shooting with a fake-a-lake.

You may want to do some distributor cap and rotor inspection. Look for any very fine cracks around the center post to any outer post. That could cause starting issues also. How long since it was tuned up? You may want to replace the cap, rotor, and plugs if it has been a while. Easy and not to expensive either.

If you do get it running, and it is sputtering but running, turns the screws evenly, in 1/4 turn increments, in the same direction (out or in), until it smoothens out. If it does, that is about as good as you will get it without having some equipment hooked up. If you can't get it going, seek a high form of help.

Good luck!