I bought a new push mower last year that I only use to mow areas I can't get to with my riding mower. This consists of under my deck, under apple trees, etc. Generally it only gets about 10 minutes of use each time I mow, so it has very low hours on it.

Last fall I was mowing with it and it just cut off and I couldn't get it started again. Fortunately I was pretty much finished so I just left it. Next time I mowed it started right up, ran for a few minutes, then cut off again. Again, I couldn't get it started. I tinkered with it throughout the fall but was never able to get it to start again. Since I didn't need it any more as we went into winter, I just put it in the garage and figured I would fuck with it again in the Spring.

Well, Spring is here and I need to mow. I already replaced the spark plug (which didn't need to be replaced, but I had an extra one so I figured it was worth a shot). Any ideas? If it helps, the engine is a Briggs & Stratton Model 90000, 550e Series.

3/28/2013 10:39:56 AM

My money is on: bad diaphragm on the carb.

[Edited on March 28, 2013 at 10:51 AM. Reason : .]

3/28/2013 10:49:40 AM

^ would it go bad with that little use? I mean it literally has less than 2 hours of use on it. It's just odd because I expect these types of issues out of a 5+ year old machine, but not something that is practically brand new.

3/28/2013 10:54:39 AM

If it just sits a lot I think the diaphragm can dry rot. Conversely, it also gets worn out with normal use.

Problems are exacerbated with fuels containing ethanol... which I'm assuming is what you used; if so, did you use ethanol fuel treatment? Did you run it dry prior to long periods of no use?

3/28/2013 10:57:24 AM

I only put Premium gas in my lawn tractor, so I used the same fuel in the push mower. I am sure it still has ethanol in it though. Haven't used any ethanol treatment. Have never run it dry, but it didn't necessarily have long periods of non-use. I was using it regularly throughout the spring/summer/fall last year, but I was just using it for 10-15 minutes at a time.

I am thinking I need to try some carb cleaner first to see if that helps. All of my research is pointing to some sort of carb issue.

[Edited on March 28, 2013 at 11:10 AM. Reason : a]

3/28/2013 11:09:33 AM

octane isn't going to matter for ethanol fuel issues. It certainly sounds like a carb issue and I said diaphragm because I know those tend to go bad and cause the exact symptoms you've described (but so do many other issues). And just one winter storage with ethanol still in the system can ruin an engine... happened to my dad's boat engine. I would certainly start with taking apart the carb and any tubes/lines connected to it and the air intake; clean & inspect. You can check the diaphragm when you do this; just be careful as there is a small spring under the diaphragm that is easy to lose.

[Edited on March 28, 2013 at 11:16 AM. Reason : .]

3/28/2013 11:16:04 AM

I was having a similar issue last year. I took apart my carb, cleaned it, and put it back together and everything works great now (didn't have to replace the diaphragm).

3/28/2013 11:32:46 AM

i would put money on it being a carb issue. break it down, clean it out and look for any cracks or tears in the diaphragm. if the diaphragm is damaged replace it. in the future do one of two things...1) add ethanol stabilizer to your fuel. the new ethanol fuels can really do some damage to small engine fuel systems. 2) use gas with out stabilizer but when you are done, empty the gas tank then start the engine and run it till it quits. basically run it dry.

3/29/2013 11:46:58 AM

small engine troubleshooting is easy. you need 4 things:

1) fuel. remove the air filter and pour a bottle cap or two of fuel down in the carb and see if it'll fire up.

2) air. doesn't sound like this is your issue. pretty much all you can do here is try to run it without an air filter, because that's about all that'll keep you from getting air.

3) spark. pull the sparkplug out. reconnect the sparkplug wire. ground the metal body (the part where the wrench goes) of the plug on the engine block. get someone to pull the rope and look at the electrode to see if it sparks. i know you've already tried a new plug, but it could be the coil.

4) compression. this one is easy. pull the rope slowly and see if you can feel the compression stroke.

my money is on gummed up carb due to ethanol. needle valve is probably hanging. best thing you can do for small engines is dump or siphon the fuel out and run it wide open until it shuts off at the end of mowing season.

[Edited on March 29, 2013 at 6:29 PM. Reason : dfas]

3/29/2013 6:28:09 PM

Got it running. Removed the carb, took it apart, and cleaned it real good with carb cleaner. Works like a charm now.

I will definitely take your advice on running the gas out of it before storing it this fall.

4/10/2013 8:47:24 AM

^awesome. yeh, I always pour out the gas and run my equipment dry if I'm not going to use them for at least a month. However, I think I'm making the switch to TruFuel. 93 octane, no ethanol, and pre-mixed. It's more expensive, but better overall and won't harm your equipment. Just something to think about.

4/10/2013 9:03:31 AM

^ My Dad swears by that stuff.

4/10/2013 7:02:11 PM