Fuel problem (1990 50hp Force)

[Probus]

Hello all,
I have a 50hp Force 1990 (D) outboard that has been sitting for a year an a half in my side yard. Ive refurbished the boat its attached to and did the basic maintenance on the engine, but it was left sitting unwinterized (fuel in lines and whatnot).

Im trying to get it started now, but i think im having fuel line problems. It turns over fine, and runs for a few seconds when ive sprayed carb cleaner into the carb, but not without. Ive got good fuel flow from a portable tank thru the bulb, to the point where it inputs into the fuel pump of the engine. Can anyone help me troubleshoot it past there? Is it likely that (ethanol) fuel has damaged the seals in the carb? or fuel pump?

Can i take the fuel line off the input to the carb and crank the engine to see if any fuel comes out to rule out the fuel pump?

Im pretty mechanically inclined but am ignorant of some of the working of an engine.

Any help would be greatly appreciated...

Thanks in advance,
Justin

 

[robert graham]

Re: Fuel problem

Re: Fuel problem

You probably should get all the old fuel out of the system from tank to carbs, drain each carb, start with fresh fuel with stabilizer in it, your carbs may be fouled already with old fuel and need cleaning. Install water/fuel separator(Walmart $27), easy to install on your transom with 2 screws, will save you a lot of fuel related problems. Good Luck!

 

[Probus]

Re: Fuel problem (1990 50hp Force)

Thank you for responding.

The engine is only single carb, so thats a plus for me, but as i said im not terrible familiar with working on engines. I do have the repair manual for my engine and all the contained diagrams/schematics. a simple question, can i disconnect the linkages then remove the carb from the engine body via the 2 bolts that hold it on? Im not asking for advice on the particulars of this engine for removing the carb, just asking the basic question; can i remove the carb from the engine body relatively simply so that i can disassemble and clean the carb in my garage on a table.

**UPDATE**

when i pump the primer bulb it becomes hard, then very hard. If i continue and squeeze it very strongly i see fuel spurt out of 2 areas of the carb, a small hole on the right side and somewhere on the left. (after doing so and cranking the engine, it runs on that spurt of fuel for a few seconds, but then returns to turning over with no fuel (i assume)) i dont assume this is any crack or break in the carb, just me flooding it with fuel pressure. Again, im not versed in engine function, so i dont know if this is a valuable piece of the puzzle or just me spraying gasoline everywhere for no reason lol.

 

[pnwboat]

Re: Fuel problem (1990 50hp Force)

The two nuts on each side of the base of the carb, maybe the throttle linkage (to access one of the nuts that hold the carb on), choke linkage and fuel lines need to be disconnected to take the carb off. About 15 to 20 minutes worth of work. Tilt the carb upside down to drain the fuel from the fuel bowl.

Probably a good idea to replace the fuel pump diaphragm too.

 

[Probus]

Re: Fuel problem (1990 50hp Force)

Thanks!

I removed and disassembled the carburetor and cleaned it with carb cleaner, as per my manual (it was gummed up in several places, to such an extent that i was sure no fuel was able to pass before i cleaned it). I reassembled and reinstalled it to the engine.

During the process of dissasebly i may have distorted the shape of the end of the idle tube from circular to oval.

upon hooking everything back up and giving her a try she started after several seconds of choke and with the throttle on high idle warmup. she ran horrible, i almost immediatly reduced the throttle to what i was hoping was going to be a stable idle but shes shaking and popping and coughing and not running smoothly at all.

I am thrilled that the carb clean worked to solve the fuel flow problem, and quite proud of myself for being able to do it, but now ive got her running, but running terribly. she sounds like shes about to quit any second and is shuddering while running with a big shake and kind of pop noise every second and a half or so.

My question: What next? did i damage the idle tube and thats the problem? Remember this engine has been sitting for a long time with bad fuel in it, although she seems to be getting fuel fine now (as far as i know, which isnt much)

Thank you all so much for helping!

 

[Jeremy90bay]

Re: Fuel problem (1990 50hp Force)

popping sounds more like a missfire. did you check spark on both cylinders? I would check for spark and go from there.

 

[john from md]

Re: Fuel problem (1990 50hp Force)

Clean your plugs and check to see if they are both sparking. If they are, then it is likely your problem is fuel. You may want to check your fuel pump diaphram to make sure it is not also gummed up.

John

 

[Probus]

Re: Fuel problem (1990 50hp Force)

Thank you all so much!

My dirty carb cleaned and my fuel lines all tightened, thanks to your collective good avdice, she ran, but not well. A new pair of plugs and a retermination of a plug wire later, shes running like she always had, not purring like a kitten, but not crappin out in idle lol.

Many thanks to all those who replied, and all those whose valuable other posts helped me DIY my boat and engine back into business!

Justin