This weekend I picked up a riding mower for $50 from a buddy manages a farm, it is a Craftsman LTX1000 with a Briggs & Stratton 24HP Commercial Series engine (not the stock engine).
My buddy described the engine as "blown". He said he was mowing, heard a loud bang and lots of black smoke, and the mower died. Since he was on a farm he just pushed it into the barn and grabbed a different mower to finish his job, and the mower sat there as is until I picked it up (I think around a year or more).
When I got it home, I noticed that one of the spark plugs was missing - so I think the "bang" was the spark plug blowing out. The threads seem totally fine, so I threaded in a new plug (replaced the other side as well), added a new fuel filter, sprayed some carb cleaner in it, and drained/replaced the fuel. I also confirmed that it has at least some amount of compression by putting my finger in the spark plug hole and manually turning the flywheel. It has alternating pressure/vacuum in the chamber, and both sides feel the same. It now fires up, but runs real rough - lots of black smoke, throttle is inconsistent (as the throttle is increased it goes from idle to super high revs to low revs and then dies at full throttle). It has enough power to drive around but definitely not the 24hp it's supposed to have, and it dies easily when the mower deck is engaged and it's under load. I have run about a half tank of fuel through it, so it's not just the carb cleaner burning off or anything. It does run slightly better with the air cleaner removed (I have a new air filter on order) but still not well. It also has a cracked vacuum hose that runs the fuel pump (I have a replacement hose on order as well) but I electrical taped it up and it seems to be relatively air tight for the time being.
Any ideas on what to try next? I am not very experienced with lawn mower engines but am extremely mechanically inclined - used to be a professional bicycle mechanic, and have rebuilt carbs on my Honda motorcycle and done a fair amount of work on cars and trucks. Thanks in advance for any advice.
My buddy described the engine as "blown". He said he was mowing, heard a loud bang and lots of black smoke, and the mower died. Since he was on a farm he just pushed it into the barn and grabbed a different mower to finish his job, and the mower sat there as is until I picked it up (I think around a year or more).
When I got it home, I noticed that one of the spark plugs was missing - so I think the "bang" was the spark plug blowing out. The threads seem totally fine, so I threaded in a new plug (replaced the other side as well), added a new fuel filter, sprayed some carb cleaner in it, and drained/replaced the fuel. I also confirmed that it has at least some amount of compression by putting my finger in the spark plug hole and manually turning the flywheel. It has alternating pressure/vacuum in the chamber, and both sides feel the same. It now fires up, but runs real rough - lots of black smoke, throttle is inconsistent (as the throttle is increased it goes from idle to super high revs to low revs and then dies at full throttle). It has enough power to drive around but definitely not the 24hp it's supposed to have, and it dies easily when the mower deck is engaged and it's under load. I have run about a half tank of fuel through it, so it's not just the carb cleaner burning off or anything. It does run slightly better with the air cleaner removed (I have a new air filter on order) but still not well. It also has a cracked vacuum hose that runs the fuel pump (I have a replacement hose on order as well) but I electrical taped it up and it seems to be relatively air tight for the time being.
Any ideas on what to try next? I am not very experienced with lawn mower engines but am extremely mechanically inclined - used to be a professional bicycle mechanic, and have rebuilt carbs on my Honda motorcycle and done a fair amount of work on cars and trucks. Thanks in advance for any advice.
