Funny I get new posts on this thread today. I just got done repairing the mower.
I’ve been down with a cold/flu/sinus infection for the past few weeks, but the other day I felt better enough to get to work on it. Keeping things simple and within my limited technical expertise, I cleaned the filter, changed the oil, replaced the spark plug, and drained the gas, refilling it with fresh gas mixed with Sta-bil to treat the gas I couldn’t get out. This morning I got it all completed and fired it up. I let it run for a few minutes and it sounds just fine with a nice, even tone.
Naturally, today it’s pouring so I can’t mow anything.
Thanks for all the input. Hopefully this has fixed it and no further repairs are necessary.
It can surge because of a vane-air governor moving back and forth (bad spring) or varnish in the carb or a vacuum leak from carb to engine. If you put it away with a low tank of gas than it’s very possible that the level was at or near the pickup tube and it varnished on the mesh screen covering the end. look for a broken or disconnected governor spring and then pull the carb and spray some carb cleaner around the throat at pickup up tube. You can scratch the varnish off the screen with your fingernail.
Well, that didn’t work. As I mentioned before, I changed out the gas, oil, sparkplug, and cleaned the filter. It ran fine for the back lawn, but halfway through the front lawn it went back into the VroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroom cycle. Interestingly, it did it around the same point it did it last time – after running about 20-25 minutes.
Next step, when free time appears, seems to be to clean out the carburetor and see if that fixes things.
If it was anything like my first mowing of the season, there was little grass and a lot of thatch and dust. Clogged up the air filter in 15 minutes. It’s not unreasonable to think that the air filter is clogged up again.
I have a foam air filter and I just clean it really well in the kitchen sink with Dawn dishwashing liquid. Wring it out real good and put a few drops of motor-oil on it and squeeze it to distribute the oil through it and reinstall.
Once I’m cutting grass again and all of the decomposed grass and dust is gone, it’s usually good for the rest of the year.
BTW, the only reason I clicked on this thread was because I caught the LANmower typo and wanted to see the smartassed comments.
All I can say about this entire thread is that ALL my small-engine machines are MTD brand. Snowblower, Lawnmower, Garden Tiller, Generator, etc. As long as I have treated them right (i.e. running them out of gas at the end of each season before storing them, buying fresh gas for them twice a year (putting the excess in my car to avoid wasting the old gas), cleaning air filters, changing oil at the start of every season, using the oil grade the owners manual specified, yadda yadda yadda), I have never had a problem. They always start on the first pull. Never had any problem with an MTD. All I can think of is that either: A) you are doing something wrong, or more likely, B) the things you are buying are junk. Several of my machines are well in excess of a decade old, but they keep working, year after year, starting on the first pull. Someone is doing something wrong, here. Either the equipment owner, or the equipment manufacturer, or both. Beyond that, I can’t say.
