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View Full Version : Briggs and Stratton 12.5hp engine won't turn


Fizeau
Jun 30, 2007, 04:31 PM
I have an older MTD with BS 12.5hp mower I inherited. I had to change starter when I got it and it ran fine. Last week I died on me twice (seemed to not get fuel and died). It started back up after 5 minutes without anything on my part. Today I go out and it turns over a little, then bogs down. I can turn the engine by hand (very hard) about 1/4 rev and it will crank over to the same point and bog again. The blade belt is loose. I have it in neutral, but the mower will not roll. It is like the drive is engaged. I tried pushing the clutch, Moving from gear to neutral, Blade engaged and disengaged all with out any success. The mower will not roll freely nor turn over. Any ideas? I have put $200 into it already (starter and steering) and don't want to get much deeper on the old machine. Thanks for any ideas.

grasswhacker
Jul 2, 2007, 06:05 PM
I have an older MTD with BS 12.5hp mower I inherited. I had to change starter when I got it and it ran fine. Last week I died on me twice (seemed to not get fuel and died). It started back up after 5 minutes without anything on my part. Today I go out and it turns over a little, then bogs down. I can turn the engine by hand (very hard) about 1/4 rev and it will crank over to the same point and bog again. The blade belt is loose. I have it in neutral, but the mower will not roll. It is like the drive is engaged. I tried pushing the clutch, Moving from gear to neutral, Blade engaged and disengaged all with out any success. The mower will not roll freely nor turn over. Any ideas? I have put $200 into it already (starter and steering) and don't want to get much deeper on the old machine. Thanks for any ideas.
Fuel is continuing to flow into the cylinder when stopped and freezes the crank. Liquid won't compress. Remove the spark plugs, let it crank a few times blowing out the fuel. Replace the plugs and it should be fine. Put in a fuel line shutoff valve from Home depot ($5) to help prevent that. It's a common problem.

Fizeau
Jul 3, 2007, 06:18 PM
I had time to check things out today. I pulled the sparkplug and tuned the cylinder a few times and stuck it back in. Bam! The mower started up and ran great. Cut the whole yard without any problems! Thanks so much!!

MOWERMAN2468
Jul 4, 2007, 09:27 AM
Ok , Hang On There Not So Fast, You Need To Change Your Engine Oil, It To Probably Has Gas Mixed In It That Can Cause Premature Engine Failure. Also, Change The Oil Filter If Equipped.

Fizeau
Jul 4, 2007, 12:54 PM
Great! I wa thinking that I needed to do that as well. I got new blades earlier this season. It looked like the blades had never been sharpened or changed. I know that my Dad had the thing for 8 years. Who knows when the last time the oil was actually changed. Thanks for the help!