L110 Cranks But Won't Start

So a few months back, I posted saying that my L110 would barely crank. That problem was easily solved with a new battery.

Now the bigger problem: It will crank all day, but not start. Last fall it had a tune up, and ran as of October.

A few observations of what's going on:

1) The spark plug is firing, and is new as of the tune up at the end of last mowing season.
2) The tank is full of treated fuel, filled a few months ago.
3) When cranking, I smell no fuel. I also smelled no fuel when I pulled the spark plug to check its condition.
4) The yellow bulb with the little filter in it is about 20% full of fuel. When I crank it, no fuel seems to enter or leave.

I fear that fuel isn't making it into the cylinder...actually, I'm almost certain of it.

This lawn mower was incredibly dirty when I inherited it last year. While I did clean it up and have all filters changed, I'm worried that something is clogged. I'm also worried that what ever is pumping or drawing the fuel has broken while the mower sat over the winter.

Any thoughts would be greatly appreciated.

Thanks!

I would pull the carb and thoroughly clean it. I would also dump that old treated fuel for fresh gas. You only want to use gas 30 days old or less. Your car can handle older fuel. Small engines its harder on them. If you spray carb cleaner into the carb will the engine start? I think you will find that even thought the gas is treated its poor quality fuel and plugged up the carb. Post engine model info here and we'll go through the steps to R/R the carb

ndutil86 said:

So a few months back, I posted saying that my L110 would barely crank. That problem was easily solved with a new battery.

Now the bigger problem: It will crank all day, but not start. Last fall it had a tune up, and ran as of October.

A few observations of what's going on:

1) The spark plug is firing, and is new as of the tune up at the end of last mowing season.
2) The tank is full of treated fuel, filled a few months ago.
3) When cranking, I smell no fuel. I also smelled no fuel when I pulled the spark plug to check its condition.
4) The yellow bulb with the little filter in it is about 20% full of fuel. When I crank it, no fuel seems to enter or leave.

I fear that fuel isn't making it into the cylinder...actually, I'm almost certain of it.

This lawn mower was incredibly dirty when I inherited it last year. While I did clean it up and have all filters changed, I'm worried that something is clogged. I'm also worried that what ever is pumping or drawing the fuel has broken while the mower sat over the winter.

Any thoughts would be greatly appreciated.

Thanks!

Click to expand...

Thank you for the response!

It's a Kohler CV491S 17.5hp Engine.

Also, I should have mentioned this earlier, as it may help with a diagnosis:

Last fall, the mower was initially brought in for service because it had accidentally been filled with diesel fuel by the previous owner. When it was serviced, the tank was emptied, filters changed, and spark plug changed. After bring serviced, it ran (although a bit rough). That was 7 months ago.

Could the diesel fuel have damaged the carburetor?

Just to update:

I took the air filter housing off (cleaned it all up in the sink and let it dry (air filter is brand new)), removed the solenoid from the bottom of the carburetor, checked to make sure that it was clean, moving freely, and functioning (it was), removed the bowl at the bottom of the carb, checked to make sure that the bulb is freely moving (it is). Throttle cable opens and closes the carb as it should. The outside of the carburetor body was dirty ("was"...it's clean now). The inside was basically spotless. Even the bulb where fuel floats was spotless.

I hit all visible parts with gun bore solvent...not as harsh as carb cleaner, but better than nothing. I then blasted everything with compressed air. I was going to take the whole carburetor apart, but for the life of me I couldn't figure out how to remove it from the engine body. ...there must be something else holding it on.

Anyway, I put it back together, tried starting, and nothing. Actually, I take that back. It burned the solvent that I sprayed into the engine, so I got one quiet fire...at least we know the plug is firing properly.
But, no fuel is making it to the carburetor. Even if fuel flow was poor, there should have been some fuel in the bottom of that bowl that I removed...there was nothing.

Could the jets of the carb be clogged from old fuel? Sure. Should the carb be rebuilt at some point? Probably. But, is it the reason that it won't run at all? I don't think so...

I wanted to remove the fuel line from the carb and try to start it, seeing if the pump will even move the fuel...but I couldn't get that line off no matter what I did.

So, now I'm ordering the potential issues like this:

1) Bad Fuel Pump
2) Clogged Fuel Line
3) Clogged Carburetor Jets

I just ordered a fuel pump, and will hopefully have it in a week.

In the mean time, I'll remove the old fuel from the tank.

Does anyone have any advice on removing the fuel line from the pump (and possibly one day from the carburetor)? These lines don't come off very easily (probably a good thing), and I don't want to break anything while trying to remove them.

Thanks

Removal
Disconnect the fuel lines from the inlet and outlet
fittings of the pump.

EngineMan,

Thanks for the diagram Any advice on how to remove fuel lines that have sort of become "stuck" to the fittings over the past 10 years? I really don't want to damage the lines...

Remove pump from engine with lines on, leave in hot water for a few minutes, then pull apart, well that's the way I have done it in the past..!, you can always fit new fuel lines.

Its always cheaper and better to replace fuel line then try and save them and ruin carb inlet fittings, fuel pump fittings, gas tank fittings. Remove clamps, and cut small slit in the full line where it meets the fittings. Remove. Purchase 1/4" non fuel injection fuel lines. The fuel injection hose is 4 bucks plus a foot. the fuel pump, and gravity feed mowers are low pressure. Go to the auto parts store and purchase 4 feet. That will give you plenty to replace and have extra. Just ask for 1/4" fuel line get the black stuff, not the clear.

ndutil86 said:

EngineMan,

Thanks for the diagram Any advice on how to remove fuel lines that have sort of become "stuck" to the fittings over the past 10 years? I really don't want to damage the lines...

Click to expand...

Sounds like a duff fuel pump.