Model 944.361200.mower won,t start in colder weather,once temp gets above the70degree mark it will start,but blue smoke comes form exaust.mower will start right away every time once engine is hot.fresh gas in tank,have yet to change oil or plugs,or filter,clean mower after every use and check filter and oil and plug..mower only2 years old...

SOURCE: Have a Briggs & Stratton lawn mower engine, 4.5

Is Blade new or causeing vibration .Chge blade,

Please rate Thank you jj505

SOURCE: MTD Yard Machine 22'', 4.5HP, 190cc push lawn mower won't start

The primer bulb might be damaged, or the carburator diaphram could have been damaged if carburater cleaner was used.

SOURCE: lawn mower ony runs at idle and dies after seconds

try holding the throttle open

SOURCE: Brand new weed eater lawn mower blowing white smoke.

Pull air filter see if theres any oil in it,make sure the oil isnt overfilled. Push mowers usually smoke like that if theyre overfilled,or tipped on thier side,if there is oil in filter simply take filter off,drain oil to correct level,and run it till smoke goes away. If none of this is the problem rings are probably shot. Weedeater is a cheap brand and theyre made cheap too,not made to last.

SOURCE: Yard-man model 12a-979L401 won't start (9 years old)

Hi,
My dad always taught me, rest his soul, that basic 101, if you have gas getting to spark, SOMETHING out to happen.
I'll ask a series of questions and propose some possible solutions. Hopefully we'll crack this mystery. Warning, this might be a tad lengthy... ha
1. Is the spark plug firing?
To check the coil that sends spark to your spark plug and the plug itself:
You can remove the spark plug from your engine and reconnect it to the spark plug wire while it just lays on your mower. pull the starter rope (make sure you're holding down the kill lever on the handle). Look at your plug end as you pull the rope.
Got spark? If yes, go to the next step, flagged ***. If no, look at the end of your spark plug that would go into the engine. The "L" shaped finger should be gapped from the small circular shape on the plug... this is the "gap". Your manual may provide specs on how wide this gap should be. If there is no gap, your plug won't work properly. The "L" shape is a soft metal and can be bent... create the proper gap. Try the test again to see if the plug is sparking. If not, you may have an issue with your coil.
***Yes to spark. Let's look at the gas issue now. OPTION 1. I will tell you that in my experience, water in gas is a major culprit for a mower not running. You've replaced all the filters... good.
I'm not sure of your mower, but most models have a "bowl" bolted to the bottom of the carburator. Sometimes moisture can get in the gas, get trapped in the bowl and won't go away or won't allow gas to get to the spark. Loosen the bolt... it's ok if gas from the bowl spills from this, the bowl doesn't hold much gas and it won't drain your tank. Plus, this means your carbuator is allowing the gas from the tank to the bowl. As you are looking at the gas spilled on the mower deck, see if there are beads of water in it. As you know, water and gas doesn't mix. This would be a tell tale of the problem. I would carefully remove the bowl from the carb and wipe it dry, then reassemble the bowl.
To be on the for sure side that you have no more water in your system, you could disconnect your fuel line from the gas tank and drain it out. Use a jar or container... you can see water in the bottom of it. You can reuse the gas too... just don't include the water!
OPTION 2. If your carb and tank are now H2O free and you're still getting to results, you may have a clogged jet on your carburator. This little pin-hole passage allows gas to pass through to the spark. Sometimes a mower sitting up a while, can cause a laquer effect to gas and it can block this passage. Removal of the carburator from the engine is required and a simple pin can be pushed through this passage to knock a "plug" out.
Geez I hope I didn't miss anything! ha
Good luck to you... I hope it's a quick and easy fix.