WOW! Craftsman garden tractor caught on fire

[flusher]

How about this...........

One morning my wife runs into the bedroom yelling for me to get out in the garage. Our new MTD riding mower was sitting there cranking away like mad trying to start ALL ON ITS OWN! The key was off and this mower is cranking full tilt and had melted the harness and the starter/solenoid was smoking....

Had it checked by the local authorized MTD shop and was told to go back to Lowe's and pick out a new one...........yikes.....ever since that happened the new one now sits out in the back shed so if this happens again we don't burn the house down.

Spooky experience to have first thing in the morning.

My TSC 42" mower, another MTD product, is in the shop now with electrical problems (battery keeps running down).

Looks like I'll be keeping that thing outside in the future.

 

[arrow]

Hope that was at the starting line cjt or at least after the traps near the return road and not at 200mph.

 

[Blagadan]

Go check your home insurance Axeman. A friend of mine had a problem like yours. His ride-on mower went on fire last summer as he was mowing his lawn. He checked his house insurance and the garden equipment was covered.

 

[dbdartman]

No electrical involved, just stupidity. When I lived in the suburbs, we had a neighbor up the street with a 8-900 sq ft corner property. He bought the wife a new Craftsman 12HP 36" riding mower (talk about over-kill!). Well, I didn't see it happen, but did see the results. Evidently she'd raked the leaves (it was obviously late Oct/early Nov) into the gutter in front of the house & was trying to "mulch" the leaves with the mower. What I saw driving home that afternoon was their nearly new mower (not more than 1.5 years old), sitting at the curb burnt to a crisp! BTW, they hired a lawn care service from that point on. Probably safer that way for all within shouting distance!

 

[Racer71]

Axeman,

Sounds like motovation for that new tractor you have been thinking about.

 

[Superduper]

Axeman, I had a difficult time starting my craftsman tractor once and then when it started, I saw gas dripping from the front of the hood area. I opened the hood and air filter to find the carburetor flooding and fuel pouring from the front. Being a side draft carburetor, the excess fuel drained off the carb instead of into the engine. The engine was still running! After turning off the engine, an emergency visegrip was used to stop the fuel flow by pinching fuel line. Luckily, the whole thing did not catch on fire but it was only a matter of time -- the fuel was dripping onto the hot exhaust pipe and smoking. Rebuilding carburetor did not help, I had to replace it with a new one which fixed it. BTW, I should say that the Kohler engine backfires occassionally, often when it becomes overly lean from opening choke too fast and when I bounce on the seat (operator presence switch shuts off fuel solenoid). This may be what has happened to your tractor. Walking away from it while it was running probably did it in. If the carb flooded while you were there, you would have noticed either the gas or the odor. These carbs don't seem to hold up too well and corrode easily. I also think that design wise, the engine kill method should be in the form of ignition kill rather than fuel shutoff solenoid. Ignition kill = engine off; fuel solenoid shutoff = leaned out mixture = backfire.

Fast forward: I am in the process of switching the kohler engine for a diesel. Read my other post about this.

 

[ctjstr]

Hope that was at the starting line cjt or at least after the traps near the return road and not at 200mph.

Yeah..it was right after the hit on the throttle. Picture was taken from just about the starting line. Sat me up in the seat a bit though.

 

[dieselgeek]

Awesome looking bike and pic. What happened exactly? looks like something coming apart, not just a fire?


I tune EFI on all kinds of drag and bonneville cars. Cool to see someone else into racing also has needs for tractor info like myself!

-scott

 

[JDPN]

not the first time
my neighbor's caught on fire and burned to the ground. All that plastic only fueled the flames.

 

[ctjstr]

Awesome looking bike and pic. What happened exactly? looks like something coming apart, not just a fire?


I tune EFI on all kinds of drag and bonneville cars. Cool to see someone else into racing also has needs for tractor info like myself!

-scott

The way we build these engines is really the cause of the problem. The cylinder has a .150 wide fire ring machined onto the top of the cylinder, which stands about .040 tall off the top flat surface of the rest of the cylinder. The head has a corresponding groove in it, which I machine to a depth of about .036. This allows a .004 crush when you torque the head down. No head gasket. I dont' know whether its because of that or something else, but we have to re-tighten the head bolts about 3-4 times after heat cycling the engine, before they are really set. If you forget, or run out of time or whatever, and a head bolt is a bit loose, the fuel, in this case nitro methane, will seep between the head and the cylinder and light. At that point it becomes a blow torch and forces itself out the path of least resistance. In the picture you can see what looks like sparklers flying out of the engine. That's molten aluminum being blown out of the head by the force of the combustion process. Because of the nature of the fuel, the bike will keep running through the quarter mile if you let it. By then a small hole is pretty big.
On that particular pass, I didn't realize at first what had happened and thought the big flare up I saw was a flash photographer. The bike accelerates from 0 to 100mph in just over 2 seconds so there's a lot going on when you hit the throttle. It took about 2-3 seconds for me to realize what had happened and get off the throttle.
When its all said and done, all you can do is tow back to the pits, pick the aluminum off your leathers and re-build the engine. I've tried welding up the holes but never had much success. The weld never holds like the original billet does. Eventually you end up buying a new set of heads, which costs between 4 and 7k, depending on what you use. At those kind of prices, I do everything I can to preserve them.
We're working with some of the funny car guys right now, trying to come up with a copper seal to use as more or less a head gasket. We'll see. Failing that, I'll just add some juice to the diesel on the tractor, put on my helmet and take a spin around the pasture.