1996 mariner 5hp carb problem. I think.

[robert53a]

This has got me stumped. The motor would only run at full choke. Ok. dirty carburetor. I cleaned it thoroughly and then it ran at half choke. Ok, I missed something. Tear it down for a second time and very thoroughly and meticulously clean and very carefully by the manual reassembly it again. Now it will idle for a good long time but slowly dies like it runs out of gas. I check the bowl and it's full of gas, so the carb is getting fuel. Also dies if you try to accelerate in gear. Has any one else had problems with these motors? Thanks......Robert ps.motor serial number is OD990014 394

 

[jeffersondodson561]

Re: 1996 mariner 5hp carb problem. I think.

Carb base gasket?

 

[JB]

Re: 1996 mariner 5hp carb problem. I think.

Does that carb have a Welch plug just above the throat of the carb? Did you remove the plug and physically clear the orifices into the throat? This is very commonly overlooked and those orifices must be open to get fuel into the airflow.

 

[robert53a]

Re: 1996 mariner 5hp carb problem. I think.

Thank for the input. there is no welch plug, but a plate with an oval and round rubber plugs. The manual states to remove the plate and plugs and reinstall the passages under then are free and clean. The carb has many little connecting air passages in the body. I have sprayed them Several times with gum-out cleaner and blow them dry with a compressor they all appear clean. I found a new carb on line for 160$, I may have to resort to that. The Japanese carburetor are far more complex than omc, it seem more so than need be......Robert

 

[jeffersondodson561]

Re: 1996 mariner 5hp carb problem. I think.

Have you verified that the main jet is the correct size?

 

[robert53a]

Re: 1996 mariner 5hp carb problem. I think.

when I first took the carb apart, it still had the factory loctite on the screws. I bought this from a friend who bought it new and ran it for five hours and pretty much just let it sit. I'm pretty sure it's the correct main jet, but the only way to know for sure is with a pin gauge kit. It ran a little better after the second cleaning, so I just may need to soak the body over night in cleaner or should I do something else? I appreciated all the input. Thanks......Robert

 

[brandon110]

Re: 1996 mariner 5hp carb problem. I think.

Did you remove the air screw? and what is it set at? also are you running on a portable tank not plumed into the boat fuel tank? if on a portable tank have you checked to see if the pick up has come unglued?

 

[M9.9]

Re: 1996 mariner 5hp carb problem. I think.

Obviously starving for fuel. Sit it in a bath of gum out and soak overnight in a warm setting; clean with a tooth brush, blow-out would be the first step for a Sitter.
You might visually check fuel pump materials for both leaks and gummed flow valves. Check choke operation and setting when warm.

 

[robert53a]

Re: 1996 mariner 5hp carb problem. I think.

Thanks again to every one. I will disassemble this carb for the third time and clean it again. It will run good at above idle, so I think it has to be in the slow speed circuit. I'm going to order a new slow speed jet, as the illustrated part catalog show something different than whats in there. parts cataloge says it supposed to be a screw in jet mine appears to be pressed in........Robert

 

[robert53a]

Re: 1996 mariner 5hp carb problem. I think.

Thanks again to every one. I will disassemble this carb for the third time and clean it again. It will run good at above idle, so I think it has to be in the slow speed circuit. I'm going to order a new slow speed jet, as the illustrated part catalog show something different than whats in there. parts cataloge says it supposed to be a screw in jet mine appears to be pressed in........Robert

Hi Just a follow-up footnote to this problem. This problem was solved by taking the carb body to my local repair shop and having it cleaned, as suggested, in their ultra sonic cleaner tank. The motor now runs perfect and I'm very happy. So if you can't get it clean with the spray stuff, bet it u/s tanked cleaned. It was reasonable at $15 ans was returned squeaky clean. Thanks to everyone for your help.