Trouble starting engine - valve open?

[wetbirks]

I am troubleshooting an engine that won't start. I have a brand new battery that's fully charged so I'm moving on to gas delivery. At the top of my gas tank I see a valve. Should it be open or closed?

See attached photo

Thank you

[Al Schober]

That's a 1/4 turn plug valve for shutting off the fuel. I'd guess that yours is in the OFF position.
Those valves are prone to corrosion, making them hard to turn. But make them too loose and they leak air into the fuel line (yours is at the top of the syphon).
My choice would be a stainless ball valve. Connect to the tank fitting with a nipple. Other side goes to your fuel line, with either a barb fitting or a longer nipple with the threads cut off one end (doesn't chew up the hose like a barbed fitting).

[Peter]

Open to run engine, closed otherwise.

In the closed position it prevents fuel from siphoning out of the tank if a leak develops somewhere in the system. Valve is mandated by CG I believe.

Peter

Al beat me to it

[Al Schober]

Peter,
You snooze, you lose. Tell us about your avatar???

[JOHN COOKSON]

That valve will have to be open so fuel can get to the engine.
The raw water cooling valve should be closed when cranking a no start engine.
A fully charged battery does not guarantee that you have spark. Have you confirmed that you have spark? Have you tried shooting starting fluid into the carburetor while cranking the engine? We will be able to help further if you could supply details. The first step is to figure out if the no start is due to a problem with fuel, spark or compression since all three are needed for the engine to start.

ex TRUE GRIT

[Peter]

Peter,
You snooze, you lose. Tell us about your avatar???

That is a picture taken on a dead calm day in about 10 feet of water just off Mason’s Island in Mahone Bay, Nova Scotia. Incredible how clear the water was and how calm it was.

Better wake up!

Peter

[wetbirks]

Thank you all for your help so far. I opened that valve but the fuel is not running down the line. I know this because I opened the valve and then unscrew the hose clamp and looked inside and there is no fuel running and the line with dry.

Is there a pump that draws a fuel into the engine?

[Mo]

Take a pic of the engine on the side where the carb is. A manual pump will be right behind the carb. An electric pump, depending on type, could be located in the same position or on a bulkhead close by. Pics will help. The guys are correct as well, that valve is closed. You likely won't see fuel unless you have a pump to pull it. Ensure on joints are closed well with clamps so it doesn't suck air.

Next, is this boat new to you. If so will want to know when it was last started, when that gas in tank was put in there, if it was treated with stabilizer. Bad gas is always a concern on engines that haven't been started in a while. When the engine is turning over ensure the choke is working.

Fuel
Fire
Compression.

All should be checked if this is a new to you engine or hasn't been fired up in a while.

Hope that helps, but we have to remember there sometimes a combination of things that cause an engine not to start. More info on the engine would be nice such as the last time it was running, if it has fire at the plugs and compression.

[Mo]

That is a picture taken on a dead calm day in about 10 feet of water just off Mason’s Island in Mahone Bay, Nova Scotia. Incredible how clear the water was and how calm it was.

Better wake up!

Peter

Pretty common to look down at the bottom in 18 feet of water around here when its been calm for a little while. I'm off to Bra Dor Lakes in a few weeks...should be a good run. I"ve got over 600 nm on so far this season and expect to rack up another 600 on that trip alone.

[wetbirks]

Take a pic of the engine on the side where the carb is. A manual pump will be right behind the carb. An electric pump, depending on type, could be located in the same position or on a bulkhead close by. Pics will help. The guys are correct as well, that valve is closed. You likely won't see fuel unless you have a pump to pull it. Ensure on joints are closed well with clamps so it doesn't suck air.

Next, is this boat new to you. If so will want to know when it was last started, when that gas in tank was put in there, if it was treated with stabilizer. Bad gas is always a concern on engines that haven't been started in a while. When the engine is turning over ensure the choke is working.

Fuel
Fire
Compression.

All should be checked if this is a new to you engine or hasn't been fired up in a while.

Hope that helps, but we have to remember there sometimes a combination of things that cause an engine not to start. More info on the engine would be nice such as the last time it was running, if it has fire at the plugs and compression.

Here are more photos of the engine. The gas is brand new and the tank was cleaned out this spring. I believe all of the gas lines are new

I have just replaced all this part plugs because the old ones were testing very low..

[wetbirks]

Photo of the engine.

I did spray some quick start in the carburetor and the engine revved up but wouldn't maintain.

[wetbirks]

Here is a summary of what has been done to this motor which is new to me in the last couple weeks:

1. Before I was the owner, the previous owner cleaned out the gas tank and I added fresh gas
2. An electric starter was installed last month
3. I completed an oil change this week
4. Today I opened the gas line valve which is at the top of the gas tank
5. Today I installed 4 new spark plugs because the old ones were testing very low
6. When attempting to start I did spray some quick start in the carburetor. The engine revved up but would not maintain.

I should mention that the engine was running last week prior to me completing the oil change. However I think I ran the gas tank dry.

Any other troubleshooting suggestions would be greatly appreciated.

[jcwright]

You mention that you think you ran the gas tank dry. After adding fuel and opening the fuel valve, did you prime the carburetor using the priming lever on your mechanical fuel pump?

[JOHN COOKSON]

The fuel pump itself may need to be primed depending on your boat's fuel system is set up. The A4 fuel pump can have problems with dead lift.

ex TRUE GRIT

[Mo]

Thanks for the pics and info. So it came alive with a shot of ether so we know it will start. You have a mechanical fuel pump. As suggested try priming the pump and again, ensure your choke is opening and closing fully. After that I'd think about the amount of gas in the tank..is there enough for the pickup tube to grab some.

Those mechanical pumps work for extremely long periods of time before any problems occur with them. However, occasionally they do develop a pinhole. I think, however, that because it fired up on ether there should have been lots of opportunity due to rpm to pick up gas and keep running.

That brings me to filters and carb. I'm wondering if there wasn't some sediment left in the tank that plugged the main jet on the carb. If you were able to just loosen the fuel line fitting coming from the fuel pump to the carb and turn it over you should see fuel leak around that fitting. If that is the case I would go to remove the carb and definitely clean it. Not a huge job, just be careful of your gaskets and clean the jets. If you are able blow some compressed air through everything by all means. When removing the jets ensure to use the correct size screwdriver and remember when assembling you don't need to tighten those jets back in with major torque, just snugged with wrist pressure...done. Clean up the needle valve as well. If it is your first time at a carb just take your time and I think you will do fine. I really think you will find your problem with the main jet...it is so hard to get a tank clean and then there is disbelief if dirt end up in the system.

Hope that helps.