Push Mower Engine Problems

[LittleChief]

Greetings all,

I have a Sears self propelled (front wheels) push mower that has some sort of engine problem. Here is what I have done so far:

Replace oil
Replace air filter
Replace spark plug
New Gas
Replace blade (just part of getting ready for spring mowing)

The engine starts easily and runs smoothly. It runs until it just begins to sputter and stop. This happens after about 30 minutes or so of use. What could be causing this? Carburetor? Heat?

I let is sit for 30 minutes (cooling down perhaps) and it starts right up to repeat the process. Any suggestions on what the problem is for you small engine guys and a solution.... Thanks for your help.

[mrcaptainbob]

Clogged fuel tank cap. It's not allowing for air relief. To test, just crack it open a bit and try running it..... If that solves it then pick out any bug or spider nests.

[LittleChief]

Never in a million years would have thought of that. I'll take a look.

Added: My first thought was that it was an air issue as the regular air filter was pretty clogged. I cleaned it last year versus replacing it, then replaced it the other day. Didn't make any difference or just a small amount of difference perhaps. Then I thought "spark plug". Doesn't seem to be it either. Thinking back, last year I replaced the fuel tank cap as the original one got lost. This may well be the whole problem as last year is when I noticed this problem and could never find a solution. I was actually considering buying a new mower just because I get tired of maintenance stuff especially when I can't really find a solution.

I have a generator that is doing the same thing. Not an oil problem. Have not replaced the spark plug (yet).

Added: I am going to loosen the gas cap and if the mower runs good, I'll replace it. This should happen in the next week as mowing season has just started for me. Looked up the sealed gas cap issue and it does in fact cause small engines to sputter and stop. This happens at about one-half tank point. When the mower stops, I automatically check fuel level which changes the pressure. So, i'm thinking that the cap is in fact the issue.

[LittleChief]

Thought I'd mention that I loosened the gas cap on the mower and it ran great. Not so with the generator.

[mrcaptainbob]

That's great, Chief! Thanks for the feedback on that. Now that we have the one 'fixed', let's look at what's with the generator. Same issue? Runs for a while and quits? Describe what's going on.....

[LittleChief]

I had the generator looked at by a Honda small engine tech and the fuel pump needed replaced. Didn't even know it had a fuel pump on it.

Thanks Captain for the suggestion on the mower. After $200, the generator is running fine now. I do have another generator but it is much larger and is a pain to transport.

[mrcaptainbob]

Thanks for the info and feedback, LittleChief. Glad it's all working out for you.

[LittleChief]

Thought I would mention, on the mower I asked about above.... well I was mowing and didn't notice that the starter cord got hung up on a bush and I pulled the thing way way out. Wouldn't work right after that. Talked to Sears and they said... oh that is a pain to fix. I had taken the top cover off the mower figuring I could access where the pull start is and probably rewind it hopefully. Well, I discovered I would essentially have to take the whole top of the mower off and wouldn't necessarily know what the problem was even if I saw it. So, I bought another Sears mower.... this time a regular push mower without the drive wheels as my yard is pretty level. The powered wheels seem to be a source of many wear issues as time and use go. So, no more drive wheels for me.

The Honda generator had to go back to the repair place as it fell off a front porch when we were inside working and oil got into everything (lots of it). It wouldn't start again as I was hoping just to burn up the excess oil. Back to the shop.... another $100 spent. My other generator has problems now. It has never been looked at by a tech to date and I thought I would just get it gone over. It does not have a fuel pump (gravity fed). Always something....

[mrcaptainbob]

Gees, Chief. Some days it just doesn't pay t' get out of bed! Hope the mechanical gremlins leave you alone for awhile.