Sears Craftsman Snow Thrower Dying

I am having this similar issue w/ an 11hp Craftsman snowblower. This thing works great until I need it and then something else goes wrong. Currently It's been dying out after a few min of running. The primer bulb also got stuck in today and torn when I tried to pull it back out. I immediately thought the thing was getting too hot and would like to try this heat shield idea I see a few talking about. Any chance you can post a picture? Also any advise on replacing the primer bulb? I live in Japan and do not have access to alot of parts...snow is getting deep and more is on the way. Please advise!
~Jon

 

I have the exact same snowblower and the exact same problem as you describe. The last time it stalled, I pulled the sparkplug out and check for spark as has been suggested elsewhere in this thread. Spark looked just fine, so I don't think it is the coil / module / key. I'm still struggling with the problem. I cleaned the carb completely. It runs well for about 15 minutes but then stalls and stops and won't restart until it cools. I tried the heat shield idead posted here and that didn't work either.

 

My 15/22 Craftsman blower dies after 15-20 minutes; HOWEVER, unlike others in this thread, it starts right back up, so the spark is fine. My neighbor suggested it could be heat-related, and the coil. The guy I bought it from says clean the carb, which seemed not to help anyone else.

So, should I replace the coil? How standard is that? How hard a task?

 

larssa54, before you replaced the coil, was your snowblower dying but starting right up again (without having to wait for a cooldown)? That's my symptoms with a 536-886122.

 

Have had same issues. This year it would not start at all. Problem was flywheel key sheared. Cause of this was valve timing was off. Reset valve timing, engine started fine. Was told last year that timing may be off causing the engine to backfire and than eventually shutdown during snowthrowing. Have yet to try it out under load but will be sure to post. My local briggs and stratton service guy informed me that Overhead Valve engines need to be checked for adjustment of the valves everyyear. Hope this helps. If you need directions on how to adjust valves please let me know.

 

may be valve timing, very easy to do, if you need help let me know

 

I haven't noticed backfiring...it just gets weaker and weaker before dying. Again, it starts right up. But I'll play: how to adjust the valves?

 

Remove spark plug. Engine must be cold

1) Turn crankshaft counterclockwise until piston is at top dead center on the compression stroke.
2) Insert a narrow screwdriver or rod into the sparkplug hole as a guage, than slowly turn crankshaft counterclockwise until the piston has moved down the bore 1/4"
3) Using a feeler guage adjust rocker nut to obtain correct clerance. Exhuast Valve:
.009 to .011inches Intake Valve: .004 to .006 inches. This is between the spring and rocker arm.
4) Hold rocker nut and tighten the rocker ball setscrew
5) Re Check clearance and readjust if necessary.
6) Repeat for other valve

The valve settings are for Model# 15a114-0342-e1

If you have another model I could get you these setting also.
Hopefully this will help

 

Hello everyone,

Thanks for all the info. A few of the posts such as ChuckS and Geoff3316 have been very helpful. I have a 2006 536.881850 . It has the same problem. 10 minutes and stalls, can't restart until some time, several hours. I did some tests today about when the problem "is" and "is not". Here are some results.

Completely dry, it will run forever. I tested 40 minutes until I stopped it, then successfully restarted it. I did this several times. I then was intrigued by the heat shield idea and disconnecting the ground for the kill plug. I disconnected the ground and it started and ran. My next step was the heat shield. Before I did the heat shield, I took some snow and put it on the top shroud to cool it and it died in 10 seconds after the snow started to melt. It took several hours to restart. I then did the same test again, as soon as snow is built up on the shroud and starts to melt (moisture), it stalls. I then waited again several hours, started and began to clear snow. Snow kicked back onto the shroud and it stalled. I believe my problem is snow/moisture which will melt after 10 minutes of the engine being hot. This would then identify the electonic ingnition as a probable cause. I belive the heat shield is not working as a heat shield but as a snow/moisture shield. I have concluded it will run forever as long as there is no moisture (this correlates to a previous post about it running great when it is dry). I will try to obtain an ignition modele and replace it. I may also test a moisture shield with plastic first as temporary fix to see if this works.

I will let you know the results of my testing.

Kind regards.

 

What do you mean by ignition module (coil)? I adjusted my valves, big snow expected tomorrow, so I will know if valve adjustment did the trick. I will let all know

 

Today I had trouble keeping it running from the get-go. I consulted with my neighbor, who suggested (and brought over) dry gas. He also showed me where the drain is to let pooled gas/water out. It ran smoothly for a couple hours with no hitches.

 

Well big snow here in New Jersey today, and after adjusting my valves as previously posted I would like to report I had absolutely NO problems. Was running for 1.5 straight, 4 driveways and sidewalks in my neighbor and not one problem. I recommend having your valves checked and adjusted

 

Thanks, but easier said than done. I don't have a vehicle to carry the snowblower in.

 

I also have the 536.881850. It "used" to be a good snowblower. Now it basically dogs down in even 3-4 inches of snow and eventually stalls out. Once it stalls, the electric start won't turn over until the unit sits for a good period of time. However, I can get it started again by putting the choke on full...pulling the starter rope which lets out one or two backfires, then move to half choke and it will start. However, from that point on it just drags and I basically can't blow snow beyond the 1 traction drive setting and having to back off and clear the auger every few feet or it will stall again. Now we have more snow coming in the next week again and it looks like there are a few good leads here. Any ideas on what I should try first? the heat shield? carburetor clean? safety key override? Thanks!

 

Put some SeaFoam or Chevron Techron in the fuel tank and let it and run for an hour, let it set for 30 minutes and do it again, either product will desolve the built up varnish and hopefully a carb rebuild will not be required, I would use a little more than is recommended on the container. Have a good one. Geo

 

Geo, thanks for the reply. Since I wanted to take a little more of a peek to see what I could find, I decided to take the carb off and give it a look. To be honest, it was pretty damn clean. I sprayed all the areas with gumout. I took off the fuel tank and checked for clogs. I could not find a fuel filter in the tank that I could see so I just sprayed everything with compressed air and ensured flow. I then reassembled the carb and put it back on. It took a long time to get it started after that which after tinkering with the screw at the base of the bowl I attribute to the bowl being too tight???
Anyhow, once it was started it would not stay started. It will run for a few minutes only at 3/4 choke. if I put it on full run (no choke) it backfires like crazy and runs very erratic (the bar controlling the other end of the carb has a lot of movement). So, I am inclined to still do what you said on the seafoam, but cant keep it started. Any thoughts?

 

When you disconnected the safety key wires did you just unplug both of the wires or just one of them?

 

This thread has so many posts I get confused as to what has been suggested, did you clean the tiny hole at the top of the bowl nut(main jet) it is almost invisible on some styles, I use the wire from a twist tie to clean it. Have a good one. Geo

 

Yes, I did that tonight. I also spoke to a local repair shop today and they said this carb has 4 generations of replacements after it. Clearly sounds like B&S knows of a carb issue and can't seem to get it right. I hate to spend $55 for a simple problem and at this point I am not convinced it is the carburetor. It still will only run at 3/4 choke though.

 

Well, it looks like it was the gaskets on either side of the spacer. Replaced them and used permatex to seal the new gaskets and I just powered through week old snow and ice about 18 inches high for about 20 minutes with no hesitation. Hopefully I will get a chance to run it for a good hour or so in the near future to really give it a test. Good thing is there is plenty of snow here to work on!

 

I had the same problem. Snow blower would run for about 10 minutes then die. If I let it cool down for about 20 minutes it would start back up, but then die again.

After reading the other posts I thought it might be an electrical problem. I tried disconnecting the ground wire from the safety key, but that didn't help. Then I noticed the spark plug wire rests on a metal edge.... that part of the plug wire insulation had worn down just about to the wire. I wrapped a piece of electrical tape around the plug wire to re-seal it and also protect it from wearing again. After I did this it started up and ran without problem. Then I noticed as snow fell around the choke knob the engine would sputter.... The air intake (wire mesh) is right below the choke knob. I think as the snow melted the water was falling onto the air intake and then pulled into the fuel stream. I pulled the choke knob out and placed electrical tape over the hole. Cut a slit in the electrical tape and reinserted the choke knob. The electrical tape acting as seal around the choke knob seemed to do the trick. After making these adjustments it ran for an hour as I cleaned off the driveway without problem.

 

I follow fish770tim's solution "choke knob not sealed" , it works great! Thank you very much, do you have more engineering solution more perminent than just put the tape on the hole?

 

hi all
i had purchased a used 536.881850 did not have any problems until i started reading this forum go figure anyway i made the heat shield the one guy mentioned and disconnected the extra key ground. i have run it 3 times since and have no problems i really feel the fix was the heat shield. i think the fuel line is just to close to the exhaust system and it is causing the fuel to boil and vapor lock. anyways my .02cents
THANX FOR THE HELP
LATER SCOTT

 

I too have had this same problem of the B & S engine dying when putting it under a load. For over 5 years I put up with it and then read this thread and tried everything mention (plug, gas cap, heatshield, etc.) but nothing worked... in the end I ordered a new carburetor and now it works like a champ. The carb has been redesigned and lukily we still had deep snow in our backyard for me to go out and give it a half hour torture test and all is fine. I ordered my carb through sears and paid $60 including shipping and tax.

 

The new designed carb just improved water protection. What I did is putting a rubble washer on choke knob hole, the size of hole exactly sealed the water from choke knob. The machine keeps ever dying.

 

no, r_pan, the carb has a bigger gas bowl and shorter gas tank travel distance and has solved the gas starvation problem that so many people complain about... my problem is solved... how about yours?

 

Mine works great and only spent $1.25 from HomeDepot.

 

Well this is interesting, I have been fighting this problem now for a couple of years and was just about to give up on the snowblower. Sears told me the same thing (coil might be bad, carb might need replacing?) so I will try the fixes that are listed here first and see, too bad I won't be able to check it until next year seeing as Spring should be right around the corner here. Great thread, thanks to everyone that has given advise.

 

i had the same problem with my 8 horsepower craftsman snow thrower. i removed ground wire. made a heat shield from
insulation i got at a plumbing supply tell them it will get hot. i used tape and a o ring at the chock knob. dont know what
really fixed it but i used it twice in pa. total of 4 hrs. and did not shut down. thanks to every one on forum.

 

I own the '06 version of the 8.5 H.P. engine. The symptoms are very similar to those noted above i.e. stops running after ~15minutes under load, electric starter will not turn over after that, finally the unit will start again after completely cooling ~45 min. I have replaced the spark plug and rebuilt the carb - no improvement. I disconnected the ground wire from the red safety key, adjusted the valves, and then installed two o-rings around the choke shaft. I also tested for spark after it died (used the pull cord to turn the motor over). No improvement! The only thing that I have not done is to fabricate and install a heat shield. If anyone has fabricated one, would it be possible to post a picture of this fix? Thanks

 

I just bought a used Sears snowblower (1yr old)with the 8.5 engine and after reading these posts I checked my engine and there is a heat shield on my model between the block and fuel line. Has anyone else seen this? I haven't used it since its spring and the snow is gone. I hope it works next winter. Great forum and thanks to all.

 

Let me start off this post by saying I am not a mechanic by any stretch of the imagination but I do tinker. I have read this post a couple times and have had all the problems that are listed here. I bought the unit in Sep 2005 and it worked fine the first two winters. The unit had a recall and technician was here in Sep 2007 to add the spark arrester. There was little snow that winter and so I never used the snow thrower that year. Starting in the winter of 2008 until the fall of 2010 I had the same problems as everyone else, would start right up and run for 15-20 minutes then die. Would restart, sometime right away and sometimes after a while, but would only run on full choke and had no real power to throw the snow.

Had a pretty reputable local shop work on the unit, the tech cleaned up the carb, replaced the priming tubing, replaced the fuel cap, and ran it for 30 minutes in the shop without issue. The first snowfall of 2010 it worked fine so I thought I had it licked. The second and third and fourth snowfalls, it was back to its poor running ways. This fall I tried adding the fiberglass heat shield mentioned here without any luck. It ran for 15 minutes then died, it was also a dry day. Today I replaced the carburetor needle and seat, B&S p/n 398188, $4.89. So go back to my first sentence above! Ended up having to remove the carburetor from the unit to get at the needle seat. It is only held in place by the pressure of the needle when assembled but I needed a meat skewer to get it out, so much for having the right tool! I also sprayed Gumout every where I could on the carb and what I thought to be the jets and ports. I reassembled the unit, no parts left over, another success! I filled it with new gasoline and it fired right up. It ran very well, at least by my untrained ear, for just over an hour then died. Oh boy, here we go again, I thought! Checked the gas and it looked like it ran out of fuel. I refilled the tank. It fired right up and ran for about 20 minutes until I shut the unit off. I will not claim success until the unit works in the first snowfall this winter when it is cold outside and the unit gets wet, but it looks promising.
I will be the first to admit that I am unsure if replacing the carburetor needle and seat or just cleaning the carb, or replacing with fresh gas did the trick, I left the heat shield in place, but I kind of don’t care as long as it runs when the white stuff flies. Hope this helps any of you still struggling with this snow thrower engine.

 

i also would add an o ring at choke knob. the person who said that
was right.if water leaks there it will get sucked into carb.

 

So far so good, we got about 10" of very heavy, wet snow in the Lehigh Valley, PA last Saturday, October 29. So much for Trick-or-Treat for the kids. The snow thrower started right up and ran well for an hour on Saturday and another hour on Sunday to clean the driveway, although it was more like spitting water than throwing snow, as the snow was heavy and temperatures right around 32 deg. The engine, or at least the muffler, definitely runs hotter than I remember when I first used it in 2005/06. So hot that the plastic shrouds melt and burn a bit until a gap opens up between them and the muffler. I put in the aluminum and fiberglass heat shield mentioned elsewhere in this post but not sure that is the issue. I melted my nylon gloves on the muffler last year. I am wondering if the engine just runs hotter now that gasoline has 10% ethanol in it. I do not thiink there was much or any ethanol in the gas in 2006. Any thoughts?

 

Well, we had 4-5 inches of snow in the lehigh Valley last Saturday. Started up my snowthrower and it ran for an hour or so until I shut it down. I'll never know for sure what finally did the trick but I am pretty much convinced that replacing the carburetor float needle seat is what did the trick. Seems to fit the sysmptoms, unit would run for 145 minutes then die suddenly. Did the carb bowl empty and the needle was stuck closed. Would restart but only run at full choke, with no real power, like it was starved for fuel. It is alos running hotter, I've melted my nylon covered gloves on the muffler twice now. That didn't happen before. My advice, for what it is worth, if you aer still having the same problems as I did, replace the carburetor float needle seat and see if it helps... and keep your hands away from the hot muffler!

 

Newbie here....

This is a great thread. I am so happy I found it. I too have a craftsman 536.881800 that has been doing this for 3 years. I'm so annoyed. I leave my shoveling for last so that I have something to do while it 'rests'. So lame.

In short - I believe there are some crappy design issues. No doubt. But in the end I think the issue is your snow blower's serviceman's error. If you are truly a DYI-er, that is YOU! Bare with me...you'll be happy you found this post.

The problem you all are describing is interesting because I believe the outside environment is the most important part. Last weekend I was blowing and put it aside while I cleaned my truck off and it stalled 2 minutes later just sitting there idle. So stalling during a load condition is not the issue.

I remember always seeing a lot of moisture on the top of the blower's plastic housing (above the spark plug and carburetor). That never sat well with me.

At first I thought it stalled only when it was snowing/raining or the trees/wind dumped snow on me. But then it stalled on a dry and calm day. I then realized I can't stop snow from falling on the top because the chute spits out a constant bit of snow where the two halves meet. Great design. I hate that chute - never stays where I set it. Cheap plastic craPsman.

So after reading this post, I grabbed a beer (that's probably the most important) and marched down to the garage and I took a much closer look. On mine, there is already a rubber washer on my choke knob. However, it was not flush with the plastic housing. So water was dripping directly onto the carburetor. Most blowers don't put these controls on the top. Great design. I took a small flat head screwdriver and shimmied it down flush.

Also too...the two plastic parts on the top that meet together right next to the muffler....there was a space/gap there. A few millimeters but large enough for melted snow to drip down directly onto the spark plug and wire. Hello? Another great design. So I loosened the two plastic housing parts and made sure there was as little space/gap as I could and tightened up the screws. Pretty tight fit.

This morning we had 8". It ran like a champ - no stalls. I've never been able to clear the entire driveway without it stalling at least 2-3 times.

My conclusion is that when I service it in the spring, I never pay much attention to these details when I put it back together. So excessive moisture was my major issue. I could also have a spark plug wire that is marginal....it is 10 years old.

Also too, the engine now runs great on "RUN"...I used to have to adjust it a little towards choke. The plastic housing parts next to the muffler got wet but the plastic is pretty warm so it dries off much faster. I'm guessing that this more closed-in/drier environment in the carburetor area is beneficial to the air intake so that's why it runs better without a little choke. I'm not an expert - I just enjoy tinkering and not paying somebody to fix things for me.

One great test would be to open those two plastic parts and with the engine running, mist some water onto the spark plug area and/or the carburetor and see if it stalls and then see if it will NOT start again. Then spray some wire-dryer (get it at any auto parts store) on those areas and see if it starts. My guess is it will start right up.

As far as water not being a good conductor - That poster was partially correct. Water is a very poor conductor when the voltage is low. However, in high voltage environments it conducts pretty well. That's why it's not a good idea to stand in water when working with live electricity. Also why static electricity (shock your cat) is prominent in dry days, but very rare during humid days. This sounds confusing right...The dry air acts like an insulator and you get charged up. During humid days the moisture in the air becomes a conductor and helps discharges you.

I hope this helps somebody. I usually don't take the time to respond with answers but I wanted to with this post because nobody had any real conclusions. Tons of great ideas. You guys are awesome DIYers!

Any comments and/or questions are welcome!

 

got2solder, you know the product you are bashing and calling a "craPsman" wasn't made by Sears or Craftsman, it was made by Murray. It lasted you 10 years! So this alleged crappy piece of junk that was about the cheapest thing you could find still lasted you 10 years and is still running strong and you are giving the Craftsman name grief about it?

I knew a guy with a 12 year old craftsman riding mower who swore he would never buy a craftsman mower again. I serviced it through the years and watched the abuse it went through. It mowed 5 acres of tough bahaia grass, it lived outside in the rain. It was used to pull limbs and tree trunks around. It never had engine trouble, but it had 3 transmissions because he operated a tree service and used his 42" craftsman mower to pull sections of cut tree trunks around. The last time the transmission tore up, he was snatching a telephone pole around the yard. He cussed it and swore to never buy another piece of Craftsman junk. To me, Craftsman should be proud of the abuse that thing put up with for so long. The engine still ran good when the mower got shoved into the bushes on the back of the property.

 

I have a 47 yr old Craftsman [Murray], and it's still runs great, strong like bull. I hope to get an other 20 years out of it. Of course i maintain it very well , too many things to mention. The most durable part is the solid rubber disc.
Sid