Howdy,

My craftsman lawn tractor has served me well for many years now with nothing more needed than checking the oil and putting gas in her... so I guess I'm due.

Anyhow, I'm not so great with diagnosis, but I can change parts if I know what's wrong, thus this post...

I'd just filled the gas on the machine which has about 120 hours on it. I started mowing, and only a few minutes in the machine seemed to be losing power. Very shortly afterward (15-30 seconds maybe) there was a pretty bad crunching from the engine. If I hadn't been stopped with my foot on the break at the time I'd have thought I hit a heavy branch or something. The noise stopped the engine. Small puffs of smoke or steam came from several places all around the engine compartment. Flipping up the hood, I check the oil quick to find the same smoke coming right up the dipstick tube. Incidentally the oil level looked fine. :rolleyes:

So... my questions are:

What was the most likely cause? A friend suggested a 'spun bearing'.

I have a feeling this is most likely going to need a replacement engine. If that's the consensus, where should I look? What's the most cost effective option (including not having to replace the thing again in the near future; putting an engine in it every year would not be my idea of funzies. Lol) The emphasis will be on getting the machine up and running as cost effectively as possible, so I have a feeling that taking it down to the nearest craftsman repair shop and saying, "fix it, I'll be back later", isn't really an option. Heh.

Thanks,
James

Hi,
There is no bearing as such to spin in most Briggs. Sounds like the connecting rod. I would check by manually turning the flywheel/screen in both directions. If it is engine-related, it will either stop turning in both or spin in both fairly freely. The first would have the rod in the way of turning and the latter would have it in a position that did not interfere with anything.
If it turns and feels like it has compression, check the deck spindles. Actually you can check them first since they are relatively visible. They too can break with an awful crunch.
Tell me what you find and give me the engine numbers and I will provide links for short blocks and engines; and part numbers.
Peace,
Clarke

First, thank you for your reply.

I checked out the deck spindles as you mentioned, though I had a feeling I wouldn't be off the hook that easy. Everything seemed to be in working order there. The parts and pulleys seemed to be in place and the belt would spin everything with some effort.

As far as turning the screen on the top, that was a no go. The fins underneath looked like I could get much more traction on with my hands, so I popped the 4 star drive screws out of the top and pulled out the screen. Gripping the fins I tried it in both directions... counter-clockwise nothing, but with great effort I could get it to move clockwise about 1/4 turn. Regardless, it seems from your text I should be able to spin the gizmo from the screen alone, so it seems to me your hunch was pretty much on target?

As far as the engine numbers, I'm not sure what you need. I can see its an 18.5 HP briggs, etc, as the subject of this says, and it's in a DYT 4000 from sears. If you need something other than that please tell me where about to look, and apologies for making you work with a newbie. :)

Hi,
Never any problems from willing learners; look on the top of the engine for a black and silver plate about 1/2" x 3" that has Model, Type and Code on it. Alternately there is a tag under the seat with a 9 digit number beginning with 917.
Peace,
Clarke

From under the seat:

Model #: 917. 273643
Serial #: 050304C007615

From a white tag on the engine with briggs logo:

31P7770348E1
040428ZE43698

Hi,
Apologies for delayed answer, but had to research your options. Normally I would go with a short block since it replaces all the moving components in the engine. Labor is higher by a factor of 2 1/2 but often is still cheaper. I may be wrong in this case!
You can generally expect 1-1 1/2hr for engine replacement and 2 1/2-4hr for short blocking. The price of labor must be added to the price of the parts (plus shipping) and weighed together. Often there are inexpensive engines available (would be a long discussion there, though I think of passing it on) and it is cheaper just to go with an engine; you end up with the busted part and lots of good parts to sell, trade, give away, etc.
Okay, let me tell you about your engine. It is a 31 cu in with series of P. The 3 "7s" are bearings, carb and starter. The "0348" is the person (vendor) it was specified and made for and the "E1" is the factory, shift and color. That horsepower tag may or may not lie as they can change them with the carb (actually the diameter of the venturi of the carb) and there is no reason why Briggs cannot legally rate an engine below its actual horsepower - just not above, that is fraud.)
Now you want ot actually know the answer (don't you - do not use contractions here usually) and I can tell you that I found some good and not so good options. I will not even mention the latter. I will say to look here:
Briggs & Stratton Replacement Vertical Engines
For the 31Q777-0592 as it is the best price/option I could find. There is also another 31G777-0559 that I think fits slightly cheaper. I can give more sites. I have no affilliation with this site (or any other.) I did find another with slightly higher prices, and a bunch with significantly higher prices.
What I am saying is that it is your choice, and your pocket book, and I am willing to give my input and help. I cannot make your choice, would not want the option. I am simply here to help!
Peace,
Clarke

Clarke,

Your leg work is so very much appreciated and no need at all for expedience. Indeed, I don't know if I'll be able to scrap up the money this late in the season for the replacement. To the non-initiated trying to find this information is near gibberish. Its like throwing your penny in the fountain and hoping Google will grant your wish... I'm just really glad the above-mentioned wishing well brought me to this place!

As far as options, I really think you steered me right here. I'll be doing whatever it is that needs doing for labor myself. I think I can handle changing parts, even the engine in this case, but not being very in the know about mechanical work, "short blocking" might very well be over my head. Referencing my own past I've changed a manual transmission in a small car and assisted changing the auto transmission in my old truck. Still, I truly was just changing parts. When I called someone to ask a question, he asked me a question about the throwout bearing, and I had to have him describe it in good detail to even know what it was.

If the level of difficulty weren't actually that much harder the extra labor would be worth it to me even if it saved me a hundred bucks...
... but like I said I don't really want to get over my head.

I couldn't find 31Q777-0592 on that site. I tried changing a few things like the Q to a G and dropping the hyphen, but nothing that looked like it fit the bill came up.

31G777-0559 does indeed look like it fits the task, and I'm not at all worried about the horse power factor. I'm very likely to go with a lower HP rating if it's cheaper, but I'll want to know it's going to fit up right also. As far as I can tell, 18.5 HP is more than plenty to power that machine (read: overkill). I've seen older machines of a similar size with 7HP or less under the hood that worked just fine. If you told me there was an even smaller one that would power the machine just fine, I wouldn't have a hard time believing you.

I bought the machine for it's cup-holder. ;)

So I guess next is, how do I find out for sure if 31G777-0559 is going to fit my machine? I see the description that says less fuel tank and muffler. Fuel tank is obvious since it's on the rear of the machine... but muffler... do you think I'll have trouble salvaging the old one?

This is an unrelated question: usually I sharpen lawn mower blades with a 4" grinder with an abrasive blade. I have not sharpened them on this machine since I've gotten it. I just didn't see an easy way of getting to them. Thus, they are overdue for some TLC as I can notice a difference now from when I first got the machine in the cut quality.

Like I mentioned above, no rush on helping me out here. Beggars can't be choosy as they say, I'm in no particular hurry, and I'm very grateful for your expertise and help. :) Thanks!

James

Re: blades

They actually come off quite easily. Raise the deck as high as it will go. Take a 9/16 socket & wrench, reach under with both hands, and find the bolt in the center of the blade. Once you have the socket on, use the other hand to immobilize the blade (watch out for the sharp edge!). Wear leather gloves if you have them. You might have to scrape some crud off the bolt head to get the socket on. Pull the bolt out and the blade drops right off. When you reinstall the blade, make sure it slips over the five-point spindle and seats correctly. Blade bolt torque is 27-35 ft lbs, if you have a torque wrench. If not, put it on as tight as you can with an 8" socket wrench without straining.

If you don't quite have enough room to operate, and you don't have a jack handy, drive the front wheels up onto something sturdy, like a railroad tie or flat rocks. Chock the back wheels.

If you prefer, you can instead remove the deck and turn it over. Drop the deck to its lowest position. It's held on with three pins, one in the front and two on the sides. You also will need to disconnect the clutch cable at two points. Slip the fanbelt off. Slide the deck out sideways and turn it over.

Replacement blades, if you need them, run about $15, and can be found at a number of places, including searspartsdirect dot com. You probably want mulching blade 134149 for a 42" deck.

Tim

Re: blades

Oops, forgot to mention, if you're going to remove the deck, there are also two struts in the front that have to be unpinned as well, but it will probably be obvious.

Actually, before I completely decide upon buying an engine it would probably be logical for me to break open the broken one and see for certain what's wrong with it?

Look at the sticky by clicking on "tools and power equipment" at the top left of the page. Blade sharpening and removal is there.

The 4" grinder is not the way to go and I'll bet you didn't balance the blades?

Minimally, you probably have a broken rod. From there there is the possibility of a scored piston walls and a bent valves.

Briggs has service manuals available for you engine probably for $15 each, so you can get an idea of what your in for.

A piston ring compressor, torque wrench and a feeler gage set will be minimum new tools. You may need a flywheel puller and a large band wrench. Sometimes you need the latter, sometimes you don't.

Hi,
It would not hurt to have a look, but I for one do not do anything less involved than short blocks except on the early Intek singles with bad cams. If going to the expense of rod and crank; you might as well get all the internals.
Removal of the engine should only be 2-3 wires, 1-2 cables and 5 bolts (one on the double stack and four on the base of the engine.)
Peace,
Clarke
PS added the picture of the base. All 31 cu. in. are the same.

Model Number 303777-1165 16 HP Vanguard series

"V" twin
Is the one to go with. Keep away from those single cyl. Intek's

Well, summer came around and I finally bought a briggs 31G777-0559 from the site Crigby mentioned. I put it in today, and was rather pleased with myself for being able to get it on the machine. After charging the battery, and filling the oil and triple checking everything I did to put it on, I started turning her over... but that's all it would do. After only a few tries, the newly charged battery was out of juice, so I hooked it up to jumpers. I tried a bit more, turning her over, trying to check if it was getting fuel, etc. Nothing was in the fuel lines until I tipped it down far enough so it started to run out a little, so I popped it back on and secured the clamp. Anyway, curtailing what could be a very long story on the process, I got frustrated enough to check the web. One of the tips I saw was on getting water out of it from bad gas by blocking off the air intake briefly and repeating between some steps. I decided that was easy enough to run out and give it a try right away. Doing that, the engine started right up! Yay.

So, I let her idle for half an hour. There were no problems, so I put it in reverse, backed up no problem. Tested the mower, again no problem. Half an hour later, the main lawn I've been keeping up with while the machine was down was done. I decided to start on the taller grass on the back half, and within 10 feet of getting into it, the mower sputtered. Hitting the break I turned off the mower deck, and the engine came back up. I was about to start the mowing again, figuring a hickup or something, when it sputtered again and again until finally stalling. Turning it over wouldn't start it back up, until I blocked the air intake again for a second, but then after a full rev up, it'd sputter and stall again.

More looking around on the internet suggested perhaps bad gas, so I drained it all down and put in less than a gallon of new gas (the old gas was ~2.5 gal, and after putting it in some plastic jugs I've not idea what to do with it). Fresh gas has not helped... it mowed fine for about 5 min, and then returned to its previous ill behavior. Thus, it seems to be some sort of heat problem?

I have not yet contacted Small Engine Suppliers - Your online source for Replacement Small Engines, Tools & Parts where I purchased it, as I still don't know if this is a problem with the engine, or something I may or may not have done.

Edit: The machine cooled for an hour and a half while I made supper, composed this and tried to do some other reading. I went back out to see how it behaved while cold. It wouldn't start without putting my hand over the air intake for a second. It started, but continued to do its cycle of sputtering and stalling. The machine doesn't have a fuel pump, but its almost as if needs one? Then again, it also wouldn't make sense for it to have run just perfectly fine for the first hour of its life if it did need a fuel pump. I don't believe there is any fuel line obstruction, because when I drained the fuel take down I took it right off the fuel filter and dipped it into a bucket which filled up plenty quickly considering the size of the line. Taking the cap off the fuel tank makes no difference, so I can safely assume it isn't a plugged cap's breather hole. I don't know, not knowing much about small engines, or engines in general for that matter, I'm a little perplexed.

This could be your engine parts list: http://www.briggsandstratton.com/mai...=MS9727_LO.pdf

I used a trim code of -01

The sputtering does sound like a mixture problem. You might try moving the mixture screw, but keep track of how far and which direction you moved it. Move the screw until the engine smooths out.

Also pick up some Seafoam engine cleaner. Add to the gas.

After your happy with the engine again, you can add seafoam to the old gas. It will get rid of the water.

Always use the highest octane gas.

I took a look at that pdf. It seems I had a fuel pump which I'd mistaken as something that split the gas to two different places. The old engine had gas tubes that went in both sides, where this new one had only one. It never dawned on me that it might be a fuel pump. So, it looks like I need to get my hands on the part referenced at 387, part number 808656 - Fuel pump. I think I'll give that a try first. Thanks much for the pdf link.

Sounds like a good plan.

I stopped at the local parts store that carries Briggs, and they actually had the part...

... the only problem is it looks exactly like the one that came off the old engine, and I don't really need another working part. The issue with the old one is I don't know how to install it.

The old part has an inlet for the gas, and 2 tubes. One split off and went to the carb area, and the other connected to a nipple on the other side of the engine. This new engine doesn't have that extra connection. Thus I'm still a little stuck...

Why don't you call the company that sold you the engine.

One of the lines looks like fuel and the other lines looks like vacuum. Vacuum operates the pump.

Sounds like you got a engine that was set up for gravity feed gas,check the valve cover on your old engine,and see if there is a small line on it for the suction line of the fuel pump.