Outdoor Power Equipment and Small Engines - Engine Blews

I think I blew my Briggs & Stratton 15hp twin engine on my sears tractor mower ... but I want to make sure. I ran over some tall brush with the mower ... saw smoke, and the engine stopped. Can't start it since. The engine tries to crank, but won't. I had a mechanic friend check the electrical out (thinking that maybe I just pulled a wire), and he said that electrical is getting to the engine. We can not turn the engine by hand from the top of the engine. The belts seem to be loose and the starting sequence light is off when trying to start (so it seems that there is no problem with the starting sequence). The model number is Craftsman 536.255870. I really like this mower because the rear wheels turn, and it handles great ... so I'd rather fix it than buy a new mower. I guess my question is ... do you think the engine is shot? My mechanic friend told me to ask Sears if it had an engine brake, and it does not. Sears said that the fact that it won't turn pretty much tells the story. The engine is no longer made, but Sears sells a short block for $622.85 plus $38.25 for the gaskets. My mechanic friend says it's a four hour job. Any help or information you can provide would be greatly appreciated!

This seems to be too coincidental to me. Tell me, how is the oil level in the engine? I'm gonna' hope that you say it is full. What I'd be looking at (if the oil is in fact full) is a problem with the belts where they relate to the engine pulley. There are two, one for the deck and one for the transmission drive. I suggest removing both at the engine pulley and then check if you can turn the engine over, whether by hand or electrically. Post back with the oil question, and after removal of the belts.

Unfortunately, the oil level is low. However, I filled it up, and it didn't hold the oil ... I had to fill it up again. Hmmm. I'm going to try your pulley idea anyway. I also read in another post that in the twin b&s engine, I might have to take the spark plugs out in order for the flywheel to turn. Quite honestly, I never tried to turn it before (just my friend tried it when helping out) so I wouldn't know if it was able to turn before. By the way, it wasn't high brush that I mowed over ... it was more like high grass. Regardless, I'm sorry now that I didn't use a weed wacker on the stuff before I mowed over it. I'll let you know how it works with the pulleys (and the spark plugs). Any other ideas are welcomed.

Hello GreenThumb!

Sorry to say, if the oil was low, you might be right about it being blown. One more thing to check though...look at the starter gear to be sure it is not jammed into the flywheel teeth. That wouldn't have caused the smoke and the engine stopping, but just in case it bogged out and stalled, then the gear jammed when you tried to restart it, it's worth a look. (that would keep it from turning). What is the model# of the engine?

Engine model number is 402707-1235-01

Well, it seems like bad news but you will want to disassemble the engine to confirm your (as well as our) thoughts. You hate to just assume extensive damage - you want to visually know. The Sears guy is on the money with the shortblock and gasket-set prices. You now just have to figure out if this in fact what needs to be done and if you want to drop that kind of loot into this machine. Having a mechanic buddy will certainly help on the labor costs.

Thanks Puey 61 and Cheese ... you guys are awesome, and your help is very appreciated. I bought it eleven years ago for $1,100 and have been real happy with it ... and I have not been able to find a tractor mower that has turning back wheels at a price less than $3,000 (unless you know of one) so it's worth it for me to spend approx. $1,000 in parts and labor to get it fixed. So glad someone turned me on to this forum ... may the force be with you :) .

Need your help again. I purchased the short block from Sears, and they put it on back order. When calling them to check on the order, they told me that B&S no longer manufactures a short block for this engine. If that's the case (and I hope someone tells me otherwise), then I guess I've got a good reason to take it apart and have some fun. Not my area of expertise ... but what the heck.

i know that murray makes all-wheel steer riding mowers. They are the yard king mowers with 46-inch deck,22.0 hp B&S engine, hydo-automatic drive, and digital flash display but i can't find a price on it right now. i will let you know if i find a price or another aws mower. good luck.

Green,
It is true that this shortblock is no longer available. You will now, if desired, have to repair this engine with individual parts. Or perhaps, get on the Web and do a search for the shortblock. You can use either of the following two Briggs part numbers: 492102 or 499945. Good luck and let us know which avenue you're going to take.

Hey Puey I knew you were the man for this one. I have a ? along this line also. Will other available engines mount and work? Whats the big diff if not?
wandering because I have a couple twins that have dropped a rod cap or such, I did find a source for about the same $ as mentioned here, but if possible why not find one that can be fitted and still have support...
Thx

Oh Greenthumb,
If you go to the Briggs site http://www.briggsandstratton.com/display/router.asp?DocID=64103
U can get a .pdf of your parts breakdown, helps in dissasembly and re- ;) also gives you part #'s which if you try the online sears parts, http://www3.sears.com/ might be suprised how many parts are available when not looking for the whole tamato :rolleyes:

GL and I hope you let us know how its going :D

Most all larger small engines (suited for riding mowers) have the same bolt pattern. Not all. The main thing to look for is the crankshaft diameter (usually 1" diameter unless going over 20hp, then you start to find 1 1/8" and more), and crankshaft length (usually 3 5/32"). Most vertical shaft briggs, tecumseh, and kohlers have the same mounting bolt patterns and honda and kawasaki usually do too. Connections like throttle linkages, mufflers, starters, fuel lines, etc... can be pesky things to have to adapt to, but they generally don't pose any real problems for adaptations. The exhaust is definitely something to watch for though, unless you plan on building custom mufflers and pipes (which I have to do occasionally to repower with a different engine).

Here is a site that seems to have pretty good deals. I recently ordered a 12.5 Briggs. It arrived fast and came packaged well. Some engines even have free shipping. http://www.smallenginewarehouse.com/

TAS

Thx cheese, sounds bout like any typical conversion and I luv Metal fab :D

Thx Tas for the link, looks like good reference/resource.

Thanks all ... very helpful. Looks like I've got some great options ... knowing that I might be able to get a new engine (or short block) will enable me to dig into my current engine and explore without worries (if I mess it up).