# Problem with Snowblower



## ayb97 (Feb 4, 2014)

Hello All,

New to the site but seems like a winner. Looking for a little help with my Sear Craftsman Snowblower with 8.5 HP engine. I was using it yesterday and I did 3 driveways and it worked great. Later that day I went out and did a little more clean up. This time it was working fine throwing 2-3 inches of snow but when I got to the heavy stuff at the end of the driveway it would start to bog and choke itself out. While it was dyeing it would backfire and shoot flames out of the muffler. I would start it again and it would do the light stuff no problem but then once I hit heavier snow the same problem would occur. I should also mention that the muffler was getting glowing red hot. Any ideas? I appreciate any thoughts. 

Mike


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## motorhead64 (Dec 15, 2013)

Hi Mike,
Welcome to the forum. Sounds like your exhaust valve is either "sticking" or is out of adjustment. This is causing you to lose some power under load and also letting hot gases ignite outside the cylinder heating up your muffler. A valve adjustment will cure this, but it will take a few hours to do it. There is also a possibility that a buildup of carbon on your exhaust valve is preventing it from fully seating. A decarbonizing of the head would cure that. MH


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## Mr Fixit (Nov 19, 2013)

Sounds right on the money Motorhead. There is two great videos to diagnose the fix the problem available to you.


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## Shryp (Jan 1, 2011)

Uh oh, the 8.5 HP engine. Is this a Briggs OHV? There were a couple other threads from people complaining about those engines running poorly. I think the main was was by scipper77.

This might be an interesting read for you.
http://www.snowblowerforum.com/foru...ll-212cc-predator-have-enough-power-swap.html

Found the other as well.
http://www.snowblowerforum.com/forum/craftsman-snowblowers/13225-stalls-when-wet.html


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## scipper77 (Dec 4, 2013)

Yup. I've seen flames shoot out of my muffler when it was bogging and then backfiring as it failed. I have had my head off and did check to make sure that the valves were clean and adjusted properly. I'm starting to sound like a broken record concerning this engine but I have given up on mine for now. If someone else who has the bogging and stalling issue fixes theres for certain I will then take the time to do whatever they did to fix theres.

There are at least 2 other members on this forum and a whole bunch more on a link that is in post #15 of the link Shyrp posted who have bad experiences with this exact motor running fine and then bogging and stalling for no apparant reason. One member put a 212 cc predator on his and was very happy with the results. Of course his had a failed motor on the same tractor unit as ours (27 inch path right?)


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## ayb97 (Feb 4, 2014)

Thanks for all the input it is very much appreciated. When I got home from work today I drained the gas and cleaned the carb Bowl and main jet. Put all back and started it and it ran smooth for 15 minutes. Just letting it sit at idle. Then it bogged out and stalled. Started it up again and had a couple backfires with the blue flame but she started and ran another 3 minutes before bogging out again. Not what I needed before a big storm.


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## ayb97 (Feb 4, 2014)

Hello again guys. I thought I would post an update. I have cleaned and rebuilt the carb. I put in a new spark plug and gas. I did a valve adjustment. I did a compression test with the electric start and it read 90 psi. Starts right up, have to keep choke in middle or it will stall. Muffler gets red hot after 5 minutes. After stall when I restart I still get blue flame out of muffler. Anymore information or suggestions would be welcome.


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## motorhead64 (Dec 15, 2013)

If your valves are correctly adjusted, I would say you are running very lean causing your engine to run very hot. The lean condition is the reason you have to apply choke to keep it running. If you can rule out an obstruction of some kind in your muffler ie. collapsed interior, then your carburetor is not adjusted properly. Of course if it has fixed jets, adjustment is not possible. Some more detail on your engine and carburetor would be helpful. MH


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## Mr Fixit (Nov 19, 2013)

Long shot. Timing would overheat your engine's top end. Then per-ignition occurs, loss of power. Look at your plug closely and compare with overheating photos here. If you think it's similar to this one photo, then check your flywheel key. You've addressed just about everything else. Running on choke being a new problem?
Spark plug reading

NGK Spark Plugs USA


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## ayb97 (Feb 4, 2014)

The engine is an 8.5 hp Briggs & Stratton. What kind of info do you want about the carb? I pulled it off last week and my buddy cleaned and replaced all gaskets and fixed a float issue. I had the muffler off when I adjusted the valves and it looked clear. Being that were expecting over a foot of snow tomorrow night can I still use it until it stalls out?


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## motorhead64 (Dec 15, 2013)

Your call on running a machine that is running hot and lean, glowing cherry red. What I was trying to find out is do you have an "adjustable" carburetor, specifically, the high speed jet? If so, you can richen your mixture...if not, you are stuck. MH


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## scipper77 (Dec 4, 2013)

Mine blew a head gasket. I am assuming this was from running to hot. These motors are junk. Until someone figures out what causes them to run hot and stall out I'm standing by the junk comment. Sorry, its kind of known around here at this point that I'm pretty frustrated that I have a motor I can't figure out. It just happens to be this Briggs 8.5. If mine blows up it would be a blessing cause then I would have ne reason not to repower my machine. And don't get me started on the plastic chute.


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