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My lawnboy 20" is a decade old and it used to start on the first or second pull. Shockingly I guess considering its age but I always changed the oil and used fuel stabilizer.

Unfortunately last year my mower flooded and I had some real problems and ended up replacing the carb entirely, new air filters, new spark plug, several oil changes (my mystery oil additive), and now I only use ethanol free gas... but still every time I go to use it it will not turnover unless I spray starter fluid into the carb. After that I can turn it off and on to empty the bag during the course of mowing, but sure enough a week later it won't start.

I've replaced so much of it and I'm just not sure what could be the issue give. New spark plugs and the carb being crystal clean!

Please help!

rebuild your original carburetor with an oem lawnboy kit.

On a 10 yo engine, I would clean the cooling fins first thing. Hard starting is either valves out of whack or clogged/dirty carb. Could be several other things. De-carbonize the cylinder as your engine manual states. Lap the cyl head flat with a piece of plate glass and 220-800 grit wet/dry paper with soap and water. Then lap the block where the head goes.

Do you mean water flooding or fuel?

Do you have some Chinese Amazon Gambler Series carb on her or OEM?

Hi thanks, I'll try to suggest the parts I don't get lol.

I got a Chinese carb but had the original prior. It did help me to the point where I could get it started.

When I say flooded I believe it was literally under water (floodwater). It didn't last too long but maybe minutes but less than an hour.

I know the oil got water somehow because it was whacky when I drained it , not viscous. I changed the oil maybe 4 times to get it started the first time or two since it seemed to help.

Thank you for trying to help me.

Ok so I went out there to check out the carb and I realized the vane spring (I believe) was entirely missing. Thats obviously an important part to help open and close that throttle plate, but what does missing it do exactly out of curiosity?

Depending on which engine you have it could be the cause of your problems. Please provide us with the model and serial numbers of your mower so we can see which engine you have.

Best I can tell it is:
Model 10641
Serial: xx0057842 where xx might be 34 or 31 or similar
Upc is 021038106410

SirLawnboy said:

Ok so I went out there to check out the carb and I realized the vane spring (I believe) was entirely missing. Thats obviously an important part to help open and close that throttle plate, but what does missing it do exactly out of curiosity?

Click to expand...

if its the spring i;m thinking of that spring works in conjunction with the governor to control engine spreed . with the engine dead the spring should have the throttle plate fully open .

SirLawnboy said:

Best I can tell it is:
Model 10641
Serial: xx0057842 where xx might be 34 or 31 or similar
Upc is 021038106410

Click to expand...

Probably in this case, the air vane keeps the choke closed so it will start. Once the mower starts, the flywheel fins push the air vane and open the choke. Replace the spring and it should fix it for you.

All depends on which of the three carbs you are dealing with. If you have a simple choke carb, Senior and Tiger are correct. If you have an AutoChoke setup, the spring will close the choke until the engine starts running. At that point the choke will open.

Well I'm just lost now... so I got the missing spring and low and behold the mower starts on the first pull! Just like last year and its giving flashbacks of the hero it once was.
Unfortunately , after maybe a minute or two it starts doing that oscillating up and down sound and then stalls. The weird part is it won't start up at that point even if I use starter fluid and take off that spring.

So, I change the oil after this happens again and sure enough the same thing. It starts without the fluid but quickly dies and will not start back up. This thing has had so much "improvement" that I just don't know what it could be. I even shot in seafoam to clean out the spark plug, carb... added mystery oil prior. I don't think the gas is bad since it was ethanol free, but I could try draining that?

I wouldn't be afraid to throw another new spark plug in and see what happens. Your no start on starting fluid hints to a lose of spark. So either spark plug or ignition module is doing a heat soak failure type scenario.

SirLawnboy said:

Well I'm just lost now... so I got the missing spring and low and behold the mower starts on the first pull! Just like last year and its giving flashbacks of the hero it once was.
Unfortunately , after maybe a minute or two it starts doing that oscillating up and down sound and then stalls. The weird part is it won't start up at that point even if I use starter fluid and take off that spring.

So, I change the oil after this happens again and sure enough the same thing. It starts without the fluid but quickly dies and will not start back up. This thing has had so much "improvement" that I just don't know what it could be. I even shot in seafoam to clean out the spark plug, carb... added mystery oil prior. I don't think the gas is bad since it was ethanol free, but I could try draining that?

Click to expand...

Hunting and surging indicates lean condition. Either you have an air leak around carburetor intake, or carburetor is still dirty (most likely). Definitely drain old fuel and blow out tank, may have a little water in fuel, old fuel, debris.

Alright... major discovery...

It also explains a prior symptom- the mower could stall with gas still in the tank. I went to drain the fuel, the carb basically looked brand new still and the bowl didn't even have debris in it. But... the fuel line literally was jammed up. I was ready to catch the remaining fuel in a can and it just didnt.... I take off the line to inspect and I end up FORCING a rod of rubberish sludge. It seemed to be at the very least water/gas gunk because I've seen that in the past in the carb bowl, but this rod was black.

Unfortunately the gas is not falling out of the tank and I imagine there is some stoppage in there as well. But how do I clean that? I thought maybe I could let seafoam sit in there for a while and hopefully dissolve it? I took a thin wire and could push it into the gas tank but didn't notice anything before I think it turns, and I'm just not sure what the inside of those are like.
Edit - I took off the tank and dumped out the gas, shook around some seafoam and then used about 40psi of air to blow into the little gas valve and it seemed to fix the flow issue, but oddly there was not a lot of junk in the tank that I could see or hear from vigorously shaking it. I dumped in a couple ounces of seafoam just to sit until tomorrow or the next chance I get to tinker.

Regarding other replies, the spark plug is pretty much brand new as well, and I've soaked that chamber with seafoam a couple times.

at this point, I think I'm getting air, and the spark is good, but I think the fuel just isn't getting delivered from the tank to the carb. Also had a fresh oil change as well and its still clean.

You might never see this again!