# Tecumseh HM80 info needed please...



## Mike C. (Jan 28, 2016)

Hi Guys,
I have an Ariens ST824 from 1987 with a Tecumseh HM80 engine.According to my tachometer, the engine speed is set rather low on the high end,thus the machine throws rather poorly.

I have the Ariens service manual that covers this machine and it lists 3600 rpm for the high speed setting.What is not given,and I can't find it in any Tecumseh manual I own,is what rpm is this engine supposed to IDLE at?

Any help would be appreciated.Thanks.


----------



## Shryp (Jan 1, 2011)

I think it is around 1200 rpm for idle.


----------



## RedOctobyr (Mar 2, 2014)

I guess 1200 sounds a bit low to me. I have my Tecumseh idling around 1700, I think, from looking at the tach the other day. I'm trying to remember where there might be a suggested spec for idle speed, most likely by Tecumseh, but I'm not sure. 

People have mentioned that you don't want the idle speed too low, or else the oil slinger may not do its job properly, and you could deprive the internals of proper lubrication at idle.


----------



## Opfoto (Jan 3, 2013)

I also searched high and low for RPM speeds for my tecumseh driven snowthrower. Everything referenced "page 30 of the Microfiche". Never did find it....


----------



## Mike C. (Jan 28, 2016)

Hi guys,

I just dug out another manual that deals with garden tractor repair.In the Tecumseh engines section it gives 1800 rpm for all VM,HM and HH 70-120.

Then I found the owner's manual for my Toro 521 that I thought got thrown out years ago.Surprisingly,this spec is given for the HS50 engine that originally was on it-1750 rpm.Strange that they never mention the high speed setting at all.

So it looks like 1800 is probably a good number.

Too bad someone who has access to the elusive "Tecumseh microfiche card 30" wouldn't make that info available here...


----------



## bad69cat (Nov 30, 2015)

If anybody does have a microfiche card(s) I have a machine at work that will convert them to PDF files...... I'd be willing to take and them available for everyone. Just throwing that out there.


----------



## Zedhead (Jan 1, 2016)

In my experiance, these engines hold together much better if you don't run them at full RPM. 3200-3400 RPM really extends their lives. 

If your really concerned about throwing the snow, do the impeller mod. It'll help more than running the engine at higher RPM.


----------



## AriensPro1128 (Nov 9, 2014)

Try this link:

Tecumseh Service Manuals


----------

