B&S 6.75 126M02-1031-F1 suddenly backfires, will not start

goddardm27

Forum Newbie
Joined
Nov 21, 2015
Threads
1
Messages
2
  • / B&S 6.75 126M02-1031-F1 suddenly backfires, will not start
In July, 2013, I replaced a blown B&S on my Toro SR 20055 with a Briggs and Stratton 126M02-1031-F1 190cc 6.75 Engine. Have not had a single problem, at all, until last weekend. I used it, let it sit for an hour or so, then tipped it slightly onto the side (gas tank was virtually empty) to scrape off some gunk that had built up on the kickers. Added gas. Went to start it back up, and nothing. Pulled a dozen or so times, and nothing. Not even a sputter. Then, bam ... sounded like a *very* loud gunshot. Not your average backfire. A dozen more pulls, and the same thing. Seems to be coming from the muffler, not the carb. I didn't hit anything. It hasn't been banged around. Already changed the plug a few months back. I can't understand why it would suddenly die like this after only being tipped on an angle?? I tried today, a week later, and the same thing. Even tried starter fluid. no luck.
I haven't checked the flywheel key yet. Any other recommendations? Sticky valve perhaps? Aside from ripping apart the engine, any way to remedy that?
Thanks in advance!!
 

ILENGINE

Lawn Pro
Joined
May 6, 2010
Threads
39
Messages
9,855
  • / B&S 6.75 126M02-1031-F1 suddenly backfires, will not start
Let start by replacing the spark plug again. there is the possibility that when you tipped the mower you drained the gas out of the carb into the cylinder, and wet shorted the spark plug. The new spark plugs are very susceptible to fuel flooding.
 

goddardm27

Forum Newbie
Joined
Nov 21, 2015
Threads
1
Messages
2
  • / B&S 6.75 126M02-1031-F1 suddenly backfires, will not start
Let start by replacing the spark plug again. there is the possibility that when you tipped the mower you drained the gas out of the carb into the cylinder, and wet shorted the spark plug. The new spark plugs are very susceptible to fuel flooding.

Thanks for the feedback - I appreciate the help!

We finally got some decent weather and I had a chance to try a few things ... replaced the plug. No luck. Replaced the entire carb. Still no joy. I can replace the entire engine for around $180, brand-new, so that may be my next step. ( the equivalent new Toro SR goes for $500+, so I'd like to keep this one alive as long as possible, as long as it doesn't cost a fortune in the process !)
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
  • / B&S 6.75 126M02-1031-F1 suddenly backfires, will not start
Get an inline spark tester and confirm you are getting a spark.
If good then pull the flywheel nut and check the flywheel key.

Firstly you need to get a spark at the plu.
Then you need it to be happening at the right time.
 

reynoldston

Lawn Pro
Joined
May 23, 2011
Threads
92
Messages
5,705
  • / B&S 6.75 126M02-1031-F1 suddenly backfires, will not start
I agree with the spark plug test and timing first. If that doesn't do it test the compression. Spark, Fuel, Compression, Timing and it will run.
 
Top