81Views6Replies

Author Options:

Lawn mower won't start? Answered

I have a Briggs and Straton Troy Bilt self propel mower.  I hit a small stump the other day and the mower cut off.  I generally have trouble with the mower not restarting after it runs for a while and gets hot, but he next day fires up and runs fine.  After hitting this small stump it almost starts after about 4or5 pulls and then it kicks back like there is too much compression in the firing chamber.  It almost pulls the cord out of my hand and a little bit of white smoke comes out of the exhaust.  I have checked the supply to the carburetor, cleaned the carburetor, cleaned the plug and check that it's firing.  I have not checked the fuel, but I have cut grass several time since the beginning of summer with no problem.  What do you think could be the problem?  I'm very mechanically included, but I'm a little stumped on this one.  Thank you for your help!!

Discussions

0
None
cerberustugowar

3 years ago

I'm a bit late to answer this one, but by reading your question, I would of said flywheel key like other people did.

On another note, A detailed and well written question is always nice to see and helps people to figure out the problem without us having to ask you more questions. Glad you got it up and running and make sure you select the best answer. Us answer givers always love to get marked for the best answer!

0
None
roosterz64

3 years ago

It was the flywheel key sheared. I appreciate everybody's help. I found it and pulled the flywheel yesterday. I've got to wait until today to pick up a key. Nobody was open on Sunday. Again, I really appreciate all the input.

0
None
petercd

3 years ago

Timing moved due to the blade impact, hence backfiring out the carb.

Another possibility is that the crank is bent, timing is usually a cam/points on the crank.

0
None
Quadrifogliopetercd

Answer 3 years ago

Hopefully, the flywheel key did its job so the crank isn't bent. The timing is provided by the flywheel, so it will be off if the flywheel key is sheared at all. A 16th of an inch is around 8-10 degrees of timing.

0
None
rickharris

3 years ago

trying to pull the cord from your hand suggests the motor is trying to run backwards. This may be because the timeing has been upset.

In general:

1. Need Fuel - problems: Blocked fuel pipe, priming pump not working, too much fuel

2. Need air - problem: air filter

3 Need spark at the right time. - problem: timing needs setting spark usually occurs at top dead centre or just after.

4 Need compression - problem: old age, no oil

If you have those then the engine should start, any 1 missing will prevent it starting

0
None
iceng

3 years ago

You could have dislodged or broken a wire in the magneto with the stomp impact.