Tecumseh 4HP head gasket inspection - Snowblower Forum : Snow Blower Forums
 
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post #1 of 5 Old 11-01-2018, 09:58 PM Thread Starter
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Tecumseh 4HP head gasket inspection

I have an old Toro 421 (HS40 engine) that seemed low on power, so I pulled the head to check valve clearances. I am new to inspecting the heads and valves on these motors, so just wondering what others think of this one. A quick check of clearances showed 0.013" on the intake and 0.010" on the exhaust. The specs (I think) are 0.004" and 0.008 respectively". I can see alot of buildup on the intake side. Just wondering if this was a too-rich condition? or what other problems there may be. I don't see a gasket leak, but again, I am new to this analysis. I will clean off the head and valves, and recheck the clearances.

Thanks for your input.
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Paul
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1995 Toro 724, 1988 Toro 521
1980 Toro 421, 1995 Craftsman 524
1997 Toro CCR 2500 & 1994 Toro CCR Powerlite
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post #2 of 5 Old 11-01-2018, 10:21 PM
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Heck, for a hunnert bucks get a 6HP predator motor and you're good to go. (Never thought I'd be saying that but I'm convinced now.)

Joe

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post #3 of 5 Old 11-01-2018, 10:43 PM Thread Starter
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Joe: I would certainly get a predator if I needed a strong engine right away. This is to learn a bit and to do in my spare time. I actually was kinda hoping something was broke inside, then I would maybe justify buying new. I still haven't tried the predator motor.

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Paul
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post #4 of 5 Old 11-02-2018, 12:27 AM
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Garage
It might be a little on the rich side. Was the plug dark or the engine idled a lot?

If there are a lot of deposits on the valve stems I'd say the guides are a bit worn, especially if it smokes when throttling down. The exhaust valve looks pretty good to me though. Did it have a history of using oil?

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post #5 of 5 Old 11-02-2018, 09:50 AM Thread Starter
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Aveteam: I picked up the machine last season, and only got to use it once or twice, so I don't know the history. But it is 28 years old. It didn't seem to smoke or burn oil. And yes, the exhaust valve to me looks very clean. I will pull the valves, clean everything, and re-measure.

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Paul
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