Craftsman snowblower engine sound

ratkindler

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Hi folks. I have a Craftsman snowblower with a 4 HP Tecumseh engine (model 143.754122). It starts easily on first pull and works well without bogging down at all in the snow. The engine sounds like it's "skipping" occasionally. I don't know how else to describe it. I need someone with an experienced ear to tell me if there's an issue or not. It's more noticeable running on fast than idle. The other snowblower videos I've watched on Youtube don't sound like this. I've got 2 videos with the engine running on idle and fast.

Sears Craftsman Snowblower - fast - YouTube


Sears Craftsman Snowblower - idle - YouTube
 

reynoldston

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It doesn't do that under a load does it. If sitting there free wheeling it sounds normal to me.
 

X-man

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I know what you mean about the skipping. It should be fine, I've seen a few snow blowers that run like that but no problems.
 

EngineMan

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To me its running lean, or you have a problem with a valve.
 

ratkindler

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To me its running lean, or you have a problem with a valve.


I've tried adjusting the mixture screws on the carb and this was about as good as it gets. I was concerned that there was a deeper issue like a leaky valve or something like that but I really wasn't sure if running this way was normal.
 

ratkindler

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It doesn't do that under a load does it. If sitting there free wheeling it sounds normal to me.


It's kind of hard to tell since the engine sounds very different under load, but I don't think I notice it happening. Like I said, it's working great but doesn't sound as smooth as others I've heard so I wondered if there was an underlying problem that could get worse.
 

EngineMan

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Did you adjust the mixture screws under load.
 

PhilsSmallEngine

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Both of my Tecumseh snow throwers do that when they aren't under load. How much depends on the temperature and humidity. When it's below 25F, they don't sputter at all. When it's above 25F+, it tends to happen more. One has 300 hours and is 8.5hp and the other has 700 hours and is 11.5hp. They've been doing it for years. No level of carb or valve adjustment has ever completely stopped that little stutter when they aren't under load. It's nothing to worry about. Tecumseh never designed their machines to be quiet or smooth. They designed them to be worked hard.
 

reynoldston

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I have notice that same sound on other engines as well. Then as soon as they are under a load they run just fine. You can rip the engine and carburetor apart, do a valve job, install a carburetor kit spend money but don't be surprise it runs the same when your are done. If I was to do anything with that engine it would be a valve adjustment. I say use it and don't worry.
 

reynoldston

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Did you adjust the mixture screws under load.

Just wondering how do you adjust a carburetor under a load? I would think it might be a little tricky blowing snow and adjusting the carburetor at the same time.
 
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