My Tractor Forum banner

Craftsman only mows 1/2 of yard

9K views 122 replies 11 participants last post by  Jonvh 
#1 ·
I got a Craftsman mower cheap, so I figured I'd try to get it going again. After replacing the:
Starter
Ignition coil
spark plugs
battery
fuel filter
air filter

and cleaning the carb, I can get it to mow about 1/2 of my 1 acre yard. But then it stalls and won't start again for about an hour. Any thoughts? It's a model number 917.270781.

Thanks in advance for your help!

-Jon
 
#7 ·
Is the choke closing all the way on start up? That could be the hard cold starting.
Try holding a rag slightly over the intake to see if it smooths out or close choke slightly. Most rough running issues are lack of enough fuel or intake air leaks.
Many have the small solenoid on bottom of carb. Those can get hot and close off fuel abs often the ones with rubber tip will get loose and the tip will vibrate up the plunger and starve the fuel off.
 
#8 ·
Is the choke closing all the way on start up? That could be the hard cold starting.

Try holding a rag slightly over the intake to see if it smooths out or close choke slightly. Most rough running issues are lack of enough fuel or intake air leaks.

Many have the small solenoid on bottom of carb. Those can get hot and close off fuel abs often the ones with rubber tip will get loose and the tip will vibrate up the plunger and starve the fuel off.


I might have stumbled across the problem by pure dumb luck. The oil was sludge, and there was about 1/2 quart too much oil in there. After changing the oil it seems too run much better. Its raining right now, so I can't tell conclusively, but I'll give it a shot when the weather clears up. Fingers crossed!


Sent from my iPhone using Tapatalk
 
#11 ·
I had a similar problem. The diaphragm fuel pump on the carb was bad.
 
#13 ·


I went to follow your suggestion, and since the diaphragm is pretty cheap I figured I'd just get one, only I noticed something. The carburetor/fuel pump isn't the same as the manual shows. The manual shows two ports on the fuel pump and none on the carburetor, mine only has one on the fuel pump and one on the carburetor. How do I go about finding out which carburetor I've got so I can get parts for it?


Sent from my iPhone using Tapatalk
 
#15 · (Edited)
I went to follow your suggestion, and since the diaphragm is pretty cheap I figured I'd just get one, only I noticed something. The carburetor/fuel pump isn't the same as the manual shows. The manual shows two ports on the fuel pump and none on the carburetor, mine only has one on the fuel pump and one on the carburetor. How do I go about finding out which carburetor I've got so I can get parts for it?
I've seen at least one tractor that came with an external fuel pump and a "variation" of this carb.
What would normally be the fuel pump, was basically just a cover piece.
A couple more pics maybe helpful, like the back side of the above pic.

Do you see an external fuel pump?
 
#14 ·
That's the opposed twin type.
I usually just have to take them apart and spray them off with carb cleaner and wipe off the diaphragm and put them back together to make them work. But that is your fuel pump.
That carb should have a large plug in the bottom of the bowl that allows you to drain the bowl and then reach in with a fairly large screwdriver and unscrew the main jet to take it out and clean it. I have had quite a few of these clogged up and not run properly. Sometimes cleaning out the jet fixes them but usually I have to take the choke cable off and the bolts on the very top of the carb just to remove the thin top layer of the carb.I've always been able to reuse the gasket underneath it when I put it back together. I spray all the passages out good with carb cleaner and compressed air.
 
#16 ·
That's the opposed twin type.

I usually just have to take them apart and spray them off with carb cleaner and wipe off the diaphragm and put them back together to make them work. But that is your fuel pump.

That carb should have a large plug in the bottom of the bowl that allows you to drain the bowl and then reach in with a fairly large screwdriver and unscrew the main jet to take it out and clean it. I have had quite a few of these clogged up and not run properly. Sometimes cleaning out the jet fixes them but usually I have to take the choke cable off and the bolts on the very top of the carb just to remove the thin top layer of the carb.I've always been able to reuse the gasket underneath it when I put it back together. I spray all the passages out good with carb cleaner and compressed air.


The diaphragm and one of the gaskets are torn. Is this the right kit to replace them for my model?

Briggs & Stratton 694056 Carburetor Overhaul Kit https://www.amazon.com/dp/B0038U3IRG/ref=cm_sw_r_cp_api_9c5kzbB9G1CZ8


Sent from my iPhone using Tapatalk
 
#37 ·
This is correct. It is listed incorrectly in the Craftsman parts manual, but Briggs & Stratton has all of their manuals online and I was able to find the one for the engine. They list this as a variation of their pump and they do list part number 693502 as a rebuild kit for the fuel pump.

I want to thank all of you for sticking with me so far. I'm new to engines and thought this would be a fun project to work on to see if I could get it going. I can say without a doubt that I would not be as far along as I am now without you fine folks!
 
#24 ·
Yours is a four hole. You just count the number of holes that holds the front of the fuel pump on. Yours has one on each corner in the picture you posted. If you look at the diagrams or the kits for the other ones there will be two holes on one side at the corners and one hole on the other side right in the middle.
 
#25 ·
If this is the illustration I remember, the order of the parts shown in the 'blow up' image is incorrect.
On another series of posts it was noted the order was spring cup diaphragm cover. Or not, as you see fit.
tom
 
#26 ·
Now I have a different problem. I reassembled everything just on the off-chance that the gasket won't affect it significantly. I tried to start it, but in all the goofing around I've done with it there's no juice left in the battery. Can I jump it with my car, or better not to?


Sent from my iPhone using Tapatalk
 
#33 ·
I didn't think to mention this before, but in doing some research online it may be relevant. Could a sheared flywheel key be contributing to this? The reason I ask is that on my task list of things to repair are the bent tie bar and bent brake rod. It looks like some previous owner hit something big. I was going to tackle that once I got the engine going but do you think it's related?


Sent from my iPhone using Tapatalk
 
#34 ·
It happens on riding lawn mowers but not very often. Typically the belt will slip before the key will shear. I think I've seen more that had keys sheared from people turning the key on and off quickly and the ignition kicking back on jerking the engine or bouncing up off of the seat and triggering the kill switch on and off.
 
#45 ·
38:Ariens mower with Briggs and only a dual charging system.

You might consider using a full wave rectifier to turn the secondary, raw voltage system into either a charging system or to operate the PTO clutch. With a full wave, both 'bumps' of the AC produced are rectified to produce DC more efficiently than the more normal single-diode systems. A full wave has four connection points, two for the AC in & ground, and two for the DC produced. I have no clue as the the DC production as to amps or volts, but it could be sufficient to run the PTO without problem. Unless the voltage was too high, causing over-amperage flow through the electro-magnet, it should not be a problem. Might want to check what voltage is 'legal' to run through the PTO windings. You could also get a Kohler regulator that takes in raw AC and produces regulated voltage. I think it too contains a full wave rectifier. They are used to replace the selenium rectifiers in bikes like the Honda 350 of the early 1970's, being available and more efficient(reliable, also).
tom
 
#48 ·
I got this beast going! It sounds great. It has a hard time starting up, but once it gets going it does pretty good, except it backfires a little at low rpm. Does this just need to be broken in or is there still a problem? This morning I replaced the fuel pump diaphragm and the starter gear. Shame on me, I also noticed that I didn't reattach the throttle when I put the carb in. Onto the drive belt and mower deck for now, but can you let me know if there is something further I need to do on the hard start?


Sent from my iPhone using Tapatalk
 
#54 ·
I got this beast going! It sounds great. It has a hard time starting up, but once it gets going it does pretty good, except it backfires a little at low rpm. Does this just need to be broken in or is there still a problem? This morning I replaced the fuel pump diaphragm and the starter gear. Shame on me, I also noticed that I didn't reattach the throttle when I put the carb in. Onto the drive belt and mower deck for now, but can you let me know if there is something further I need to do on the hard start?


Sent from my iPhone using Tapatalk
I haven't read this full thread on your post... quiet lengthy... but I did fast-forward to the end to see how the story has unfolded so far kind of like reading the last chapter or last paragraph of a book but not reading the whole book to see how it ends without knowing how everything has unfolded.

One thing you mentioned in your post is your mower backfiring at low RPMs... Here is a link from Briggs and Stratton's website on backfire issues... hope it helps with at least that one issue you have remaining with your mower.

https://www.briggsandstratton.com/na/en_us/support/faqs/browse/engine-backfire-afterfire.html

Mikah
 
#50 ·
That only has a 3A charge system, so maybe with all your starts, the battery isn't fully charged?

Also make sure the choke is working so that starts are quick as possible.


Hmm, could be. The charger said it was at 100% though when I set it up to charge it. It ran great for about 1/2 hour. Then my wife wanted to try so I stopped and got off. When I changed out the starter gear I must not have gotten the retaining ring on very good because all the starter components were all over the engine. I fixed that but now it won't start.

So, just to go down the list,
Walmart says load testing is as it should be. Battery charger says battery is at 100%. Keeping in mind that this thing runs great once it starts, is it safe to assume that the starter is the culprit? The guy that sold it to me said he put a new starter in it, but this one is definitely not new.

On a separate but related note, I went to change the drive belt this afternoon. To do that I need to remove a pulley. I got the bolt out that holds it in place, but its stuck on there good. All the YouTube videos say to heat it with a propane torch, but I don't have one. Is there another way to get that thing off?


Sent from my iPhone using Tapatalk
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top