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Discussion Starter #21
Good luck, keep us posted. Haven't had any snow worth blowing here in S.E. PA yet. I did start mine up and it fired on the first pull! We'll see!
 

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looks more and more like carb icing

Conditions for stalling on craftsman 8HP/27" :
Temp has to be cold enough, there has to be enough moisture in the air, either a wet snow, or a lot of dry snow blowing onto the engine, and the dumb gap in the plastic chute contributes, no doubt.
snow is dumped through the gap in the upper chute, right onto the motor.

I've run it in 50 degF for an hour no problem (but of course, no snow!)

I doubt that vapor lock is an issue:
Would think higher ambient temp would help cause vapor lock.
If vapor lock, then the carb and 4 inch fuel line should cool off within minutes, not take up to an hour to allow restart.

On the other hand, ice built up inside the carb would take a long time to 'receed', and even when the ice is gone, the carb body will still be quite close to freezing temp.
It is my understanding that the high-speed, low pressure, flow of intake air will lower the overall temp as part of the Venturi effect . (those who know better please correct me if I am off track).

At 50 degF spraying water all around (snow hood off) did not affect running: directly into the intake (no effect AT ALL), sprayed heavily onto the ignition wiring (hi voltage and the cut-out). Tried to get onto the coil as best I could.

So still possible that coil/spark plug has some cold/hot sensitivity, but again it ran fine on a 50 degF day.

Carb icing restricts flow of the mixture to the engine, ie the throttle passage is smaller! This means only idle speed would run ,and any kind of applied load would not be met by increased throttle from the governor (engine has not separate throttle control), and the engine would die because it could not work against the extra load of the drive and/or auger (in my case the auger with snow would bog the engine down ).

I'm gonna try to jam a temperature probe through the intake next time this happens. (Engine not running).
 

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Discussion Starter #23
Another update. Just got through the 2016 Northeast blizzard. The snow blower would run like a champ and then just stall like it ran out of gas. I'd have to wait 10-15 min and it would start back up and be fine for another 15min. I'm considering replacing the coil. Any other feedback would be appreciated.
 

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have you updated the carb or not ?

I'm guessing that you have not yet installed carb kit
(mentioned elsewhere in this thread)

Available from Sears, Jacks Small Engines etc.

You can replace the coil, but the failure mode indicates carburetor icing

I have same engine and have finally run the motor in moist/snowy conditions,
motor has not stalled once.


You can also isolate to carb icing by making the motor run just a bit hotter:

Place Duct Tape (or a cloth, or cardboard) over the vent holes at the rewind starter. Leave one or two unblocked.
You will not overheat the motor if running outdoors in the winter.
In fact John Deere has published this procedure as a service bulletin.
The extra heat should keep the carb warmer, preventing icing inside the throttle body.

If this changes the operation in any way, ie allows the motor to run 10-30 minutes longer, then the issue is not the coil.

 

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I'd be surprised if it was the coil - but it's possible. I like the idea of blocking off the airflow and see how the heat changes things? I just looked back through the thread and you certainly have had a battle! Spraying the water when it was 55 out and that didn't kill it sure makes me think moisture is not the problem. The carb icing is starting to sound like the best theory at this point - although it was suspect from early on....

The only other thing might be that something is opening up as it heats up - like a gap in the intake area perhaps?

Perplexing one for sure!
 

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Carb kit 'should' fix carb icing problem.
Remember that even folks (like me) are 99% sure that carb icing is the issue,
I cannot promise anything.

I am 100% sure that my machine runs a lot better since I installed it.
AND... when refitting the plastic snow shield, be sure that the top and bottom pieces fit into their slots, to keep a good air tight seal near the carburetor.
 

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Discussion Starter #28
Thanks for the info, I will post back any results good or bad. Also are there any instructions on the carb replacement or is it pretty straight forward
 

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In #20 of THIS THREAD, I show a picture of the kit and indicate which pieces I used, and what I connected. Before you dismantle the carb, get a good photo of your existing governor linkages.

Also in this thread is the post from another member about covering the recoil housing...

Finally, I suggest that you re-read this thread from the beginning.
 

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I can back up what conwaylake is saying. I also have the 8.5 hp Briggs Craftsman 536.881850, and installed the replacement carb from Amazon at the end of last season. We have had a fair bit of snow in Nova Scotia this year, and the machine has not stalled once - complete satisfaction. Do yourself a favour and just install the replacement carb - easy job - just follow conwaylake instructions shown earlier in thread. Carb kit comes with everything you need and takes about 1 hr to install. I also changed out the coil but I don't believe that was the issue.
 

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HUH? That's interesting if it was truly what was going on - sounds like it is/was. I'm going to try and file this one in my memory banks because I have no doubt somebody will drag one in to me for repair and I would be chasing my tail too!! Thanks for the updates! Hope you don't have any more issues......
 

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Discussion Starter #32
Looks like I'll be doing the carb job in the near future. Also do you guys do anything special as far as fuel treatment? I usually burn off the remaining fuel once winter is over. Should I be using a stabilizer? or ethanol free fuel?

Thanks
 

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always use ethanol free fuel when possible. It sucks in moisture and eats the rubber.....
I would just drain it down at the end of the season and forget all that stabilizer stuff. Save yourself some grief...
 

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I am following this thread. I have a 2006 Husqvarna 8024STE with the same B&S engine and exactly the same symptoms and problems as the other posters. I have read everything I could find on how to fix it. I have done pretty much everything except for changing the carburetor. Some people claim to have renewed the carburetor withouth getting rid of the problems, while others claim that a new carburetor did fix the problem. I am being perplexed.......
 

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update: Carb kit has FIXED the problem

Today was the perfect condition for carb icing.
35 degF just after a 6" wet snowfall.

Machine ran for more than one hour non-stop.
No faltering or stalling.

And as owners of this type of snow blower know, the discharge chute
will dump a fair share of snow back onto the motor through the jointed section of the chute.

If you have done the carb upgrade, and your motor stills 'stalls when wet',
please post !!!!
 

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Today was the perfect condition for carb icing.
35 degF just after a 6" wet snowfall.

Machine ran for more than one hour non-stop.
No faltering or stalling.

And as owners of this type of snow blower know, the discharge chute
will dump a fair share of snow back onto the motor through the jointed section of the chute.

If you have done the carb upgrade, and your motor stills 'stalls when wet',
please post !!!!
Thank you for the update. If it wasn't my backup blower I would take action for sure. Right now I'm trying to decide between the carb upgrade or the bigger predator swap (I think it's 8 horse?) When my 8.5 briggs does run I feel that it boggs to easily.

How is the power from your 8.5 after the carb swap? Briggs did lose a class action suit because they over rated many motors including this one so I know it's really 8 HP at best.
 

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In my years of experience when a small engine is running and snow is sticking to it on top, you're likely to ice up. We run all Cat engines, tractors, small engines with a canvas heat housing around them. A small engine must also breathe warm DRY air. That's why they build a stove around the carburetor on a small winter engine. On your car they bring warm air from the stove around the manifold too.
I'm repeating myself but put a cloth in the path of the air going into the flywheel grill for 15 minutes. You'll see how much snow collects on the cloth. Your engine warms up also. Looks don't matter here if your life is at risk. Remember a warm carburetor does NOT ice up! I saw a driver on a timber jack, with an 18 mile run, battle wolves after he froze his engine in 1969. I saw this lesson live! My Sears 5 HP Tecumseh didn't run five minutes without it on. It becomes worse as the temperature falls.
 

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Congratulations and thanks for the detailed info on your other post.

You probably noticed the spacer between the carb and the motor.
The PLASTIC spacer, or at least, it is not made of metal and therefore does not conduct much engine heat.

Yes for me, the motor runs smoother and quieter and has no loss of power.
Does not bog down in a plow bank or End of Driveway.
Throws wet snow 10-15 ft, and dry snow 25+. As it did before the mod.
That flimsy plastic chute will probably hamper the throwing of wet snow.
 
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