So, I complained that I couldn’t get my lawnmower to work. I spent a great deal of time crouching in the driveway, attempting folk remedies and invoking the Forbidden Words in order to try and coax the device into doing its job. I read the replies to that earlier post, and tried some of the things they suggested. Changed the gas. Flushed out the fuel line. Cleaned out the float bowl in the carburetor. (Which inadvertently led to changing the gas, again. Oops.) Put fuel cleaning stuff in the tank. Cleaned the air filter. Checked some of the moving parts for blockage.
No change. Fie!
In the end, reader Nick was the one with the winning answer:
This is a fuel-air mix problem, if it only runs if you continually pump more fuel in, then it is running lean: there is too much air being combined with too little fuel for combustion. You said the mix screws are missing from the carby, I would say that is your problem.
You may be able to test this be restricting the airflow of the air filter, try covering the air intake partially and see if it runs.
|This is the yard AFTER it was cut. It was so tall, that it comes up to my ankle *even after it’s been cut*. Dang.|
Originally, the air filter had been loaded with oily grime. I’d cleaned it, and returned it to service. I tried the mower with the air filter in place, and without the air filter, but the problem persisted After reading Nick’s post, I went back and inspected it again. If anything, I would have thought the engine was getting too little air, due to all the dirt in the filter. But as an experiment, I took out the air filter and jammed a wadded-up paper towel into the air intake. Boom. Problem fixed.
I wrapped the air filter in paper towel and stuck it back in. I experimented until I found the right configuration of paper towel to properly restrict the airflow. Then I cut the grass.
The machine is still a bit wobbly. The mix screws are indeed missing. I’ve never had the machine apart like this, so I don’t know if they were ever there, or what. But if Nick is right, then I’m getting too much air and not enough fuel. I worked around this by restricting the air intake, but that’s a workaround, not a solution. The machine runs slowly like this, and is prone to stall. (Which makes cutting super-tall grass even more fun!) What it really needs is more gas, not less air.
So, I’ll be getting a new air filter, and seeing if new mix screws can be obtained. I’ll bet that will be a fun conversation at the shop.
“Yeah, hi. I have a mower at home. I don’t know the make or the year or the model, or how many strokes it does, but I know the carburetor is kind of beige. Anyway, I’m missing the tiny little screws that make it do the thing. Yeah. I need to buy those. What size? Oh, pretty small, I’d imagine.”
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