331877 0036 G1, every 6 seconds

[PTmowerMech]

If the carb needle and seat won't hold against the small amout of pressure a pulse diaphragm fuel pump puts out you have a carb problem. Is the tank located higher than the carb? Do you have a pressure tester? You should be able to hold carb upside down and it hold 7 psi applied to the fuel inlet. I think you are asking for a crankcase full of gas. A fuel pump should not affect the level of gas in the carb.

Funny you should say that. Because I finally got back around to this one like an hour ago. Was gonna adjust the valve because it was a little hard getting over the compression stroke. Pulled the plug and a cylinder full of gas shot out about 6 or 8 inches.
So that settle that. Off came the carb and a freshly rebuild one went on it.

The oil level didn't raise at all. So I cranked it up and let it run for a while. Barely a spit or sputter out of it. Which is surprizing. I'm not normally that good at rebuilding those nikki carbs. Guess I'm getting better.

If this keeps up, I might make a 3 by the end of summer.


P.S. I put a new pump on it also, and forgot to plug the air line into it, but it ran fine. LMAO... So what's the point of a fuel pump on a system like this, where the tank is mounted under the hood. (higher than the carb)

 

[Hammermechanicman]

I do so many carbs a dealer who doesn't want to work on older residential mowers with fuel problems calls me the carb guy and sends me work. Folks won't pay his shop rate to remove, clean, rebuild, reinstall and test a carb on an older residential mower. He just replaces and uses OEM. Have you priced a Kohler or Briggs carb lately? Plus many are NLA. Probably 75% of my work is fuel system related. I have a small commercial grade ultrasonic cleaner that was expensive but it has paid for itself. Just look at how many threads there are every week on this forum that are fuel system/carb related.

 

[slomo]

I think you're onto something there. I removed the fuel pump all together and just ran a line from the tank to the carb, with a filter in the middle. And the flooding stopped. Thanks for the idea.
It seemed only logical once I realized that the 6 second flooding increased to 9 seconds when I increased the RPM's. Engine burning fuel faster, meant that it took more time for the engine to flood. If it was a carb issue, I think it would flood all the time. That's the usual case, in my short experience in doing this kind of work.

Gonna let her run for about 10 minutes, if there's no hickup's, I'll button it back up and get'r ready to sell.


This forum is awesome.

Fix it proper BEFORE selling it. Or properly disclose the unique running problem prior to selling. I would NEVER let an engine like this go if I were to sell anything. All mine are 1-2 pulls every time, rain or shine and on time.

slomo

 

[PTmowerMech]

Fix it proper BEFORE selling it. Or properly disclose the unique running problem prior to selling. I would NEVER let an engine like this go if I were to sell anything. All mine are 1-2 pulls every time, rain or shine and on time.

slomo

Oh yeah. I sell nothing with known problems. Unless the customer knows about it prior to the sell. But that's rare. I usually fix everything I know about before for sale sign gets stuck on it.

 

[StarTech]

From your description of the solution it sounds like someone installed a gravity fed carburetor in place of the fuel pump version.

 

[PTmowerMech]

From your description of the solution it sounds like someone installed a gravity fed carburetor in place of the fuel pump version.

That could very well be true. But the engine cover was made with the holes for the fuel pump. everything looks stock. Who ever did the swap, did a bang up job.

I have a good mind to just remove the fuel pump and install a shut off valve. There's no real need for a pump on this engine. Unless there's something
i'm missing.

 

[Hammermechanicman]

I have seen lots of mowers from the factory that should just be gravity fed with fuel pumps. Probably that way because they bought thousands of the same engine for different models. I put a shutoff valve on every gravity fed rider i work on. Not if but when it fills the engine with fuel.

 

[slomo]

I have seen lots of mowers from the factory that should just be gravity fed with fuel pumps. Probably that way because they bought thousands of the same engine for different models. I put a shutoff valve on every gravity fed rider i work on. Not if but when it fills the engine with fuel.

Say it again Hammermechanicman, fuel shut off's for everyone!!

slomo

 

[slomo]

I do so many carbs a dealer who doesn't want to work on older residential mowers with fuel problems calls me the carb guy and sends me work. Folks won't pay his shop rate to remove, clean, rebuild, reinstall and test a carb on an older residential mower. He just replaces and uses OEM. Have you priced a Kohler or Briggs carb lately? Plus many are NLA. Probably 75% of my work is fuel system related. I have a small commercial grade ultrasonic cleaner that was expensive but it has paid for itself. Just look at how many threads there are every week on this forum that are fuel system/carb related.

Hammer, you said you have an ultra-fabulous cleaner. In your opinion, does someone that cleans say less than 10 carbs a year need one? I get by pretty swell without. Do they really clean better than soaking in Diesel overnight then spraying with carb cleaner and rotting out with a nylon bristle? Then a dual way full action air blast? Worst case they go in the dishwasher. Your thoughts?

slomo

 

[Hammermechanicman]

If only doing a few a year one like mine would not be cost effective. I used to use the Gunk and Berryman carb dip on 4 cycle carbs but not cubes as it ruins the check valves. I feel the US cleaner does a better job than soaking and spraying. I started with one like the HF one and it is slow to really clean carbs. I stepped up to one with more heat and a sweep function. Night and day to the cheap Chinese ones. I do about 2 or 3 carbs a week on average.
This is the one i have

Ultrasonic Cleaner XPS240-4L

Ultrasonic Cleaner XPS240-4L 12" × 6" × 3.75" (Tank L × W × Depth. Cleans Mechanical (Carburetor, injector, etc) and Manufacturing Equipment, Laboratory Equipment, Paint Guns, Rifles, Hand Guns, Ink Cartridges, Medical Equipment, Dentures, Tattoo Equipment, Cosmetology Equipment and much more.

www.sharpertek.com