# Flywheel torque question



## AL- (Oct 27, 2014)

I'm having problem reinstalling flywheel - see "kickback" thread below for details. Today since I noticed flywheel nut is larger on the solid state ignition model as compared to the older points behind flywheel model parts I had, I decided to recheck the torque values in the Tec manual and it says HM80 ext. ignitions have 58 ft llbs spec., and other HM80 have - 40 ft lbs. My question is, "does the solid state and ext ignition mean the same thing and requires the higher 58 ft lbs torque?"

larger nut, threads and hole in rewind cup is bigger


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## Shryp (Jan 1, 2011)

I know the old engines had the coil under the flywheel and the new ones have the coil above the flywheel. I would think ext ignition would mean external coil?


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## Kiss4aFrog (Nov 3, 2013)

:smiley-signs009: I'm not sure either but that makes sense to me.


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## AL- (Oct 27, 2014)

In the Tecumseh Tech,s Handbook it describes a "Fixed Timed System (External coil)" 

" This system has the contact points and condenser mounted under the flywheel with the laminations and coil mounted outside the flywheel. This system is identified by the square hole in stator, the round configuration of the coil. andon older coils , the word "Grey Key" is stamped on the coil to identify the proper flywheel key to be used."

So I guess I don't have an external coil. The larger nut and threads with 40 ft lbs of torque may compensate for magnets being located on the rim of the flywheel as compared to the older points type where every thing is under the flywheel.

Also wondering if anyone has some experience with an External coil system?


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## bad69cat (Nov 30, 2015)

Does this help at all: https://books.google.com/books?id=-...AU#v=onepage&q=tecumseh external coil&f=false


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## AL- (Oct 27, 2014)

bad69cat said:


> Does this help at all: https://books.google.com/books?id=-bEBXd7oUokC&pg=PA101&lpg=PA101&dq=tecumseh+external+coil&source=bl&ots=dl98ivFVYh&sig=uaIuQTSr7iAKtAyVYWiz_feoT_c&hl=en&sa=X&ved=0ahUKEwidzuem7LHLAhUFTCYKHUpmAQ44ChDoAQgwMAU#v=onepage&q=tecumseh%20external%20coil&f=false


Looks like a good book but I think we'd need a really thick book to cover it all in detail. my favorites so far for these is "Tecumseh L head engines" by Clymer and "Tecumseh technicians handbook' by Tecumseh. 
Here is pic of the different sized nuts used on the HM80's , the larger is for the newer solid state ignition. The socket sizes are 15/16" and 3/4" is a smaller for older point type. Both spec. at 40 ft lbs torque.


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## Grunt (Nov 11, 2013)

Hello AL. Since you are inquiring about flywheel nut torque settings, did you find a sheared key when you removed the flywheel or ?


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## AL- (Oct 27, 2014)

Grunt said:


> Hello AL. Since you are inquiring about flywheel nut torque settings, did you find a sheared key when you removed the flywheel or ?


Hi ! Not sheared or bent and in the grove very tight. I replaced it and torqued to 40 ft lbs,. I haven't ran it yet as I'm first trying to improvise something for the throttle lever unit - little thin bent spring washer rusted/wore and a broke half was missing. Will post


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