# Ariens 20" hs40 4 hp basket case



## slx12001 (Dec 16, 2013)

I purchased an Ariens 20" 4 hp Tecumseh hs40 powered snow blower basket case. (no model on the sno throw to be found) After putting new points in and setting correctly, Rebuilding the carb, and soldering the leaky metal gas tank I had to build my own linkages as they were missing. 
First question...
What is the correct operation rpm of the engine? I usually set idle to about 800rpm and wot at 3400-3600rpm. I have not had much experience with these old Tecumseh point engines. This engine anything over 3200rpm it sounds like it's going to blow up. I ended up setting the wot rpm at 2200 rpm as it clears good and rev limits down to about 2000rpm under a good load. So what is wot for this old points Tecumseh hs40 4hp?
Second question...
The lever for drive is harder to pull. There is no "let off" spring in the system to hold a solid feeling engagement. It seems to be more pull lever to go and pull much harder to go in deep snow. I inspected the drive and all moving parts. All seem to move freely and in good order. I bought this for a project. It has been then some. Thanks for any help.


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## Shryp (Jan 1, 2011)

I would think 3600 RPM.


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## motorhead64 (Dec 15, 2013)

*Rpm setting*

Sounds like you have a 22000 series Ariens. All of the Tecumseh snow engines were set at 2000-2200 idle and 3600 WOT. However, I have seen a torque graph that shows that 3400 is the max torque rpm for the 4 hp. I set mine at 3400 and it runs good. MH


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## slx12001 (Dec 16, 2013)

Hello, Thanks for the replies. This sno throw has an actual throttle lever. I don't believe that at idle it would be 2000rpm but ?


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## slx12001 (Dec 16, 2013)

I talked to an old time Tecumseh tec. He stated the older points engines used on snow blowers should be set to run up to 2400rpm and 2000-2200 is how they should have came set from the factory. This seems to be true as I have mine setup this way and it seems to work great. Easily blows through 1 foot of powder with out bogging. Any more rpm and it sounds like its going to detonate. Thanks motorhead64 for helping me figure out this is indeed a 2200 series Ariens hs40 4hp 20" clear sno-throw. I believe about 1970.

As far as the other issue I had with having to pull the drive lever very hard to keep drive engaged through deep snow he stated that I need to check my drive wheel shaft bushings by lifting the right and left handle. If there is play in the wheel shaft the bushings are worn and this will cause this type of issue. I replaced the bushings and now the drive lever will fully engage with a lot let effort. I hope this helps someone.


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