A gas engine mower I have recently acquired starts fine, but the wheel that normally pulls it forward jammed with grass and will not turn properly when it's running. I pulled all the grass out, including masses impacted in what appeared to be a drive gear on the wheel (with a stiff plastic housing), left over from when someone else last used it, but that didn't seem to help. I am now 5 hours from the mower, cannot even say what brand it is. But is there some sort of belt or clutch that engages the front wheel? How do these things work?

Also, a spring cotter pin holds the wheel on, but I didn't have the tools to get it off. Basically, I'm wondering what kind of tools I'll need to take with me to fix this thing next time I visit it.

Thanks for any thoughts!
Asking

Asking, there is a tool called (guess what) a cotter pin puller. Yup. I own one so I know it exists. While you are at the hardware store be sure to get more cotter pins just in case you lose the original one or it somehow gets bent.

Hi,
Yes, a cotter pin puller does exist, though it is often called other things, and is not always of as much use as a good pair of side-cutter pliers. Spare cotter pins is always a good idea, probably 1/8" or 5/64" for that and about 1" in length since the axle is normally 1/2."
Without a brand and model it is hard to help. Brand especially important since as in every industry designs are often protected by patents and not used by other brands. I am familiar with many brands and their designs. Some are similar enough so as to have compatible service techniques, and others are as different as night and day. An example would be the Toro rocking key design that keeps the machine from being harder to pull backwards.
Peace,
Clarke

Thanks, Clarke.

I've been browsing mowers and my best guess is that it's an MTD White. But I'm not sure about that. I'll get back to you if I am able to narrow it down.

It's a walk behind, self propelled with front wheel drive, 12 inch wheels in back, 6 or 7 inch wheels in front with side discharge/mulch. Pull start. Probably 22 inches, maybe a 2002 model, give or take a year or two.

The inner part of the left front wheel has gear teeth made of hard white plastic. I assumed it was a gear-driven front wheel drive.

I'll go back in a couple of weeks and get the make and model number. (And take some tools and spare cotter pins.)