Briggs and stratton backfires and yanks cord

pware · 06-04-2009, 06:22 PM

I have a lawn mower with a 4hp briggs and stratton that's extremely hard to start and when it does start it runs real hard also while im trying to start it the engine will back fire and snatch the cord out of my hand. It acks like its out of time, is that possible. I removed the head and the piston and valves appear to be in sync as far as the intake, compression, power, and exhaust sequence is concerned and the valves aint cracked. any suggestions. this problem started when I hit a piece of tree root

**Basementgeek** · 06-04-2009, 09:57 PM

Hi and welcome to the forum

Pretty sure that this the problem:

http://outdoorpowerinfo.com/repairs/flywheel_key.asp

BG

mstpops · 11-15-2009, 10:36 PM

briggs backfires and yanks cord

yes i agree the flywheel key has been sheared and ignition is out of time
this will cause the unit to kick back and ripp cord out of your hand

cheers mst pops

C.Johnson · 11-16-2009, 06:43 PM

Is the blade tight?

06-04-2009, 06:22 PM	#1 (permalink)
pware Registered User Join Date: Jun 2009 Posts: 1 OS: windows xp service pack 2	Briggs and stratton backfires and yanks cord I have a lawn mower with a 4hp briggs and stratton that's extremely hard to start and when it does start it runs real hard also while im trying to start it the engine will back fire and snatch the cord out of my hand. It acks like its out of time, is that possible. I removed the head and the piston and valves appear to be in sync as far as the intake, compression, power, and exhaust sequence is concerned and the valves aint cracked. any suggestions. this problem started when I hit a piece of tree root

06-04-2009, 09:57 PM	#2 (permalink)
Basementgeek Moderator, Home Support Join Date: Feb 2005 Location: Central Ohio, USA Posts: 1,467 OS: XP Pro SP2/Vista Ultimate SP2 Blog Entries: 3	Re: Briggs and stratton backfires and yanks cord Hi and welcome to the forum Pretty sure that this the problem: http://outdoorpowerinfo.com/repairs/flywheel_key.asp BG __________________ Donating to the forum keeps TSF free for all. Proud member of ASAP

11-15-2009, 10:36 PM	#3 (permalink)
mstpops Registered User Join Date: Oct 2009 Posts: 18 OS: xp	Re: Briggs and stratton backfires and yanks cord briggs backfires and yanks cord yes i agree the flywheel key has been sheared and ignition is out of time this will cause the unit to kick back and ripp cord out of your hand cheers mst pops

11-16-2009, 06:43 PM	#4 (permalink)
C.Johnson Registered User Join Date: Nov 2009 Posts: 4 OS: win98	Re: Briggs and stratton backfires and yanks cord Is the blade tight?