Forum - Briggs & Stratton Racing
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Registered: 07/13/14
Posts: 11
Reply with quote  #1 
I've read that the clutch must be installed on the LO206 with no end play or float, otherwise the key will tear up the crankshaft.  I have been running the Briggs flathead (with a Horstman clutch) for years with a little (0.015-.030") clutch endplay, with absolutely no issues.  I'd like to continue this practice with the LO206.

So my question is, what is the difference between the flathead crank and the LO206 crank that makes floating the clutch a problem?  Is the LO206 crank softer?  
Thanks in advance for your advice...Ken

Registered: 06/22/11
Posts: 189
Reply with quote  #2 
      What happens when a clutch is not tightened down is the entire force of the engine is transferred across too small of area (only the key itself).  If you look at our output shaft the key way runs the entire length of the output shaft.  This is for a reason and with many clutch designs use a small key.  By locking the hub down to the taper of the crankshaft, we are essentially overcoming a design issue and increasing the transfer of power across a wider area (the key way and the area of the hub locked against the output shaft).

The power band of the Raptor is a LOT different then the Animal and that is why you could get away with a lose clutch.  At Animal engagement you have 3 foot pound plus of additional torque to pound through the clutch.

We use a premium grade of carbon steel in our OHV racing crankshafts but even so the pounding overtime could cause damage.  With a sealed engine like the 206 the end result is money we don't want you to have to spend.  

Registered: 07/13/14
Posts: 11
Reply with quote  #3 
Thanks for the quick, detailed, response. Does the (recommended) washer between the clutch and radius on crankshaft have a Briggs part number?

Registered: 08/21/12
Posts: 39
Reply with quote  #4 
Id like to follow up with this too. I got a new short block (thanks fastermotors) i pulled the the old.engine and the keyway on the crank is chipped away. I put it on the new engine with the spacer on the inboard side and the crank still protrudes past the clutch about .020. Is there another spacer?

Registered: 07/13/14
Posts: 11
Reply with quote  #5 
Helix, I think you can use standard washers between the clutch and shoulder washer.
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