Carb malfunction? Starts w/ fuel directly in carb, but wont continue running

[khombat]

Hi all,

I have been having ongoing problem with my Volvo Penta 5.0L GL-A 2001 (SX Drive) engine.

I had to install a new fuel pump and now that I have finally got the pump to deliver fuel to the carburetor, the engine wont start.

I put a little gas directly in the carburetor then it started just fine but then died once it was not getting any more fuel.

I had noticed a small leak where the throttle connects to the carburetor, but doesn't appear to be a large enough leak to prevent the engine from continuing to receive gas, however the engine just dies once the fuel I added directly is used up (few seconds).

I am guessing I need to do a carburetor rebuild or buy some kit to clean it? Or is it something else?

I don't know any mechanics that could help me out and would like to know if it is something that I could do, or at the very least, what I should ask of a mechanic so I don't get taken advantage of. I have already invested $1000+ in new parts this summer, so I want to be careful as my funds are limited. I do enjoy hands on possibilities.

The fuel is brand new. I haven't had my boat out on the water since this problem occurred early last year, and my summer is disappearing on me quickly

I can get out and take pictures of exactly what I see if my description doesn't help indicate a problem (when I get home). Just let me know please!

Circled is where there is dripping of fuel (bottom side)

 

[khombat]

Re: Carb malfunction? Starts w/ fuel directly in carb, but wont continue running

Forgot to mention: Volvo Penta 3856270

 

[Don S]

Re: Carb malfunction? Starts w/ fuel directly in carb, but wont continue running

I had to install a new fuel pump and now that I have finally got the pump to deliver fuel to the carburetor, the engine wont start.

How do you know you are getting fuel to the carb? If you disconnect the throttle linkage and operate the carb linkage by hand, do you get two streams of fuel going into the carb?

 

[khombat]

Re: Carb malfunction? Starts w/ fuel directly in carb, but wont continue running

Hi Don,

Well I disconnected the fuel line from the carb to test if fuel is being passed through and it did pump gas. I don't know if it is actually getting into the bowl of the carb.

 

[Scott Danforth]

Re: Carb malfunction? Starts w/ fuel directly in carb, but wont continue running

Welcome to iBoats

I would have someone pump the throttle while you look down the throat to make sure that you see fuel spraying like Don mentioned.

if you do not have fuel spraying, could simply be a bad accelerator pump.

if you verify that there is no fuel in the bowl, then I would trace the fuel path. could be a stuck float, could be debris in the fuel inlet.

 

[Don S]

Re: Carb malfunction? Starts w/ fuel directly in carb, but wont continue running

Several questions.
1. How do you know this is a 5.0GL-A ???? It's gray which makes it a 2000 or earlier model, plus that carb was not used on the A models.
that 3856270 number really doesn't help. Do you have the serial number handy? It should start with a 4 and have 10 numbers in it.

2. Have you checked the filter in the carb inlet?

 

[khombat]

Re: Carb malfunction? Starts w/ fuel directly in carb, but wont continue running

Hi Scott,

Thanks for the information. I finally had a chance to get out there after the rain and test it. The fuel comes up all the way to the carburetor, but definitely nothing drips down the throat.

Do you think that is the accelerator pump or something wrong with my float?

Is either a relatively easy fix that I can take on or generally recommend for a trained professional?

The more information I have the better chance I have at saving $$$ Thanks so much for your feedback and I apologize for being tardy.

My engine block had cracked one year as a marina had not drained the water, so I had a rebuild, so I am not sure what happens to the serial numbers, however the number I got from that spot is only 4 digits long from what I could read 8041... Quite hard to see on my boat as it is almost totally blocked.

 

[Senior B]

Re: Carb malfunction? Starts w/ fuel directly in carb, but wont continue running

Sounds like the carb needs to come off either way for the leak. Have you removed the main fuel line from the fuel pump to the carb and cranked it over to see if you're getting fuel to the carb? If you are then your fuel pump is ok. There is a fuel inlet screen in the carb just after where the main line connects. Check to see if it's plugged up. Next I would get the Holley rebuild kit for that Carb. Looks to be the Holley 2300 2 BarreL and that's Holley Kit 703-36. Sounds like you have a stuck float or a clogged inlet valve. The carb isn't hard at all if you stick to the basic parts I'E Just remove the float bowl on the front and replace the needle valve and clean out the port, replace the power valve in the metering block, replace the accelerator pump. remove the 2 carb jets from the meetering block and run a wire through them and reinstall. These parts are all in the kit as are the required gaskets. Job can be done in under an hour. This was long winded but I have just told you how to freshen up your Carb with the $25.00 kit and hopefully cure your problem. If it's your first time attempting this, I will tell you not to disassemble the entire thing like the choke housing and throttle plates etc and stick to these basic parts. The directions in the kit are complete and fairly easy to understand. Good luck.

 

[dannyual767]

Re: Carb malfunction? Starts w/ fuel directly in carb, but wont continue running

I think that Senior B is right. It sounds to me like you've got a stuck needle and seat not allowing any fuel to enter the carb. A quick removal and replacement and you should be back in business real quick.