Craftsman Lawn tractor with B&S won't start.

I have a Sears 48" lawn tractor model 917.272264 with a 25hp B&S engine model number 446777-0165-E1 that will not start. I had finished mowing and as usual was using my leaf blower to clean the deck and exterior of the mower. It started sputtering and shut down a few seconds later. Fuel is new and full tank, filter checks good, plugs are good and both are getting spark. Battery is fully charged and turns starter just fine.

After reading many posts I can tell that when manually turning the motor, it turns way too easily....seems to have little or no compression. When using the starter, it turns rather fast but shown no sign of starting.

I would appreciate any ideas.

Thanks,
Rudy81

 

Try a splash of fuel in the carb and see if it will fire. If so, it would seem you have a fuel restriction.

 

The fuel did not do anything at all. There is fuel in the fuel filter. However, the motor just turns over, but no start.

 

Look for a wire loose, I suspect that your leaf blower somehow blew a wire off of one of the safety switches.

 

I will take another look. Will a safety switch allow the starter to even engage if not properly set?

 

No. But to be sure, unhook the kill wire from coil and try starting.

 

So far everytime I unhook a wire, it won't even engage the starter, but I will keep looking.

 

Well, so far nothing seems to help. I guess I will have to see what the Sears mechanic says tomorrow.....only $88 bucks to take a look.

 

If you have spark, (you stated you did in your first post) and fuel in the carb does not offer to fire, you can check for compression easy enuff by removing the spark plug and cover the hole with your finger, turn the engine by hand if possible and you should feel pressure build and blow by your finger.

You didnt mention how you tested for spark? These twins will generally run on one cylinder almost un-noticably different except for lacking power under load.

 

My guess is that you will have a valve adjustment issue on one, or more, valves (four total). If you're willing to have a go at an adjustment, call off the Sears tech and we'll walk you through the procedure to check and adjust such. If, on the other hand, this is within warranty then let the technician take care of the trouble. But, based on the fact that a service call is going to cost you $88 (and possibly more - depending on what they find) I'd say you are not within the warranty period and if you'd like to save some loot then let us help you check the valve train.

 

Well, it was very bad news according to the tech. Based on the speed at wich the motor turns over he is sure that "the shaft" is sheared. Indicated it will need an engine change....approx $1300.

I don't think so, I can get a new mower for a few hundred more. This stinks, the mower only had 130 hours and had been well cared for. Frankly I don't understand how a shaft can shear like that on the B&S engine. I guess that explains the perceived lack of compression when I turn the motor over by hand.

Would the compression valve problem produce the same symptoms? Any ideas on what to do from here? I think my next mower will be a John Deere, although they too have the same or similar engines.

 

Did the technician remove the rocker covers to inspect for valve train movement? Did he remove either cylinder head to inspect for piston movement? Did he indicate what the shaft is that he is sure is sheared? Sounds like you got a crackball technician and you need a second opinion or let us walk you through a diagnosis.

 

Thank you very much. This tech has been doing this for over 30 years, but that is all I know. I was not home when he looked at it, and I am sure he did not do anything to the engine other than turn it with the starter and/or manually.

Since I have no other choice, I would greatly appreciate any advice. I will be out of town the next three days, but will work on it when I return. If you would be kind enough to piont me in the right directions I will get started ASAP.

 

My thought here is why does this require a new engine? I have never in my 30 years of small engine work seen a Briggs or any other engine have a sheared shaft. I would definately have some other technician take a look. Sound to me like somebody loves to sell replacment engines.

 

I'll bet he "just happened" to have an engine to sell you for a "good deal".

 

The shaft sheared? Naaaw, I doubt that. Never seen a crankshaft or camshaft shear, although I've seen a few bent or broken because of a broken rod or balancer. It does sound like you have a blown engine. Was it low or out of oil? If the engine is blown, it still may be repairable.

 

Again, thanks for the interest and responses. The oil has always been at normal levels and I have been the only user of the mower....which had been cared for well. I look forward to ideas on where to start taking it apart. I am not a mechanic, but have taken apart my share of gadgets.

 

First before tearing it down, I would pull the spark plugs out and check for piston movement by turning the engine over manually by hand and see if you get air coming out of the spark plug holes by lightly holding your finger over the hole. If you feel air, then remove the valve covers and check for valve and rocker arm movement. Report back your findings and we will tell you what to check next.

 

Thank you. I will do that on Monday. I am currently out of town. I will report back.

 

Well, did as you asked and there is absolutely no air movement at all.....not a good sign.

 

Not a good sign indeed. You'll have to remove the engine and pull the sump cover off to see what went wrong.

 

My next project.

 

Well, that was fun! Pulled the engine off the mower and could hear noises from inside the crankcase once I drained the oil. Pulled the bottom of the engine off and....drum roll please....pieces and parts all over the place. The piston arms had disintegrated! The inside of the case is all dinged up, the cylinder walls on at least one cylinder are damaged. I guess that rules out repairing this one. Price of a replacement engine is $1700. For another $1000 I can get a John Deere X300.

Thank all of you for your kind help and patient guidance.

Rudy

 

just had to reply by saying thanks for letting us know what the outcome was

 

Do some checking around. Look on Ebay. Those engines can be had for much less. I get them new for less than half what you were quoted.

 

I have spent all afternoon looking for one. I did find a new one on e-bay for $700 plus shipping. Problem is that the part number is nowhere near mine. My dead engine is model 446777-0165, which is out of production. The one I found is a a 445777-0248. They both have the same shaft. However, I have no idea what differences exist that may prevent me from using the new one on my mower. I spent some time on the phone with B&S, trying to find out the specific differences, but to no avail. This is a no return item, so I can't afford to make a mistake at this stage.

 

Northern Tool has a 26hp B&S 44P777-0027 which is very similar to the 4467777-0027 that Briggs says is the replacement for my old one....but again, I have no idea if this will be a drop in replacement.

 

For the most part, the main thing to be concerned with is the crankshaft. If it is the same size, keyed the same, with the same threaded hole, then it should fit. The bolt pattern on all the engines in that series should be the same. There are small differences in many engines. Most differences are barely noticeable and do not affect fit. If you get an engine that is based on the same design as yours, and you find a small difference that affects the way it fits, you can remove the different part and install the one from your old engine. If the new engine doesn't have a fuel pump, but your old one did, take it off the old engine and put it on the new one. Etc, etc...

 

What specs should I look for in the shaft. Particularly the key and center bolt thread? Are the specs listed somewhere?

 

My 20 hp Murray has always had good oil levels, so I got lax in checking it. while mowing it died, similar to cutting very high grass and bogging down. I tried to restart but the starter would not turn it over.After topping off the oil level I took off the screen and tryed to turn it with a cresent wrench on the top nut. I took out the spark plugs and spayed penatrating oil and got it to unseize. but the starter still only turned it half the way and would stop, I then would get it over the tight spot with my ratchet and the stater would turn it thru the easy part. doing this for awhile it seemed to be getting easier, and then I burn up the starter silenode. I took the heads off and the piston cylenders seem smooth and all four valves go in and out. I now can turn it with just my hands and it seems even thru-out the entire cycle. I am thinking about putting it back togeather and seeing if the starter will now turn it over, but because I have not really done anything to it (other than spraying oil into the cylinder and turning the pistons in and out), I fear it will not turn over as before when the heads were on and it could build up pressure inside, (I'm thinking maybe it has too much pressure for the stater moter to overcome? and maybe the valves need adjusted???) I would appreciate any ideas.

 

SJ Harwick. - The biggest question now that you have loosen it up is where was the damage done. There is probably aluminum from the rods stuck on the crank journals and/or the main journals have aluminum from the block. You have it freed up and it may run for sometime or it could blow. How used was the engine before this happen also plays into how long it will last. What are you out other than time and head gaskets. Try it. I see a lot of smaller engines from the big box stores that the customer did not put the oil in and stuck it. With the engine being new and tighter it stuck early enough to not do a large amount of damage and when freed up, the engine ran for several seasons.

 

Rudy, the keyway should be the same across the board for all similar displacement engines. The diameter, length and thread size are what MAY be different. Since yours is apart it will be difficult to accurately measure the crank's PTO length since the measurement is determined from the point the sump mounts to the chassis, not the crank gear. You should reinstall the sump cover to accurately measure your crank length. You can then measure the diameter easy enough and the crank bolt can be measured for thread size. Be sure to buy an engine with the same dimensions so that you don't have to mess around with belt and pulley arrangements.

 

Camino Kid.. Thanks for the reply. I was hoping that only the piston rings had gotten stuck and released when I put the penatrating oil into the piston cylender. I also changed the oil and felt for grit in the old oil and could not find any, I suspose the alluminum might have been turned to power though???