Tuesday, 12 April 2011

Husqvarna not starting

I hit start and all I hear is the gears spinning around and no engine turning over.  What could it be.

Starter clutch
At first I thought the problem was with the starter clutch.  This is permanently connected to the starter and has friction plates in between the teeth below.  As you can see I removed the starter clutch and checked it out.  I didnt service it as the problem was found to be elsewhere.  The freewheel sprag clutch was not working as it should.

'A sprag clutch is a one-way freewheel clutch. It resembles a roller bearing, but instead of cylindrical rollers, non-revolving asymmetric figure-of-eight shaped sprags are used. When the unit rotates in one direction the rollers slip or free-wheel, but when a torque is applied in the opposite direction, the rollers tilt slightly, producing a wedging action and binding because of friction. The sprags are spring-loaded so that they lock without backlash.':ride:

What happened with mine was the garter spring (which is like the type of spring in an oil seal) snapped and it stopped working . (No spring loading so it would not lock) the freewheel would spin both ways.





 

Here are some shots of the freewheel sprag clutch.





The sprag clutch is easy to remove.  But an air gun can make all the difference in assisting the undoing of the 27mm nut.


Primary trasmission driving gear disassembly
Place an aluminium shim between the teeth of the free-wheel gear (in order to
prevent its rotation) and loosen the fastening nut (27 mm wrench, left side
thread nut).


All I did was fit a new garter type spring around the pull bearings.  I removed the spring from an old fork 52mm seal.  Worked a treat.

I rebuilt the gears etc, and yes, shes running great.

3 comments:

  1. my bike has the same problem super helpful, where can i buy this spring? what should i look up to find one. live in US

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  2. is there anyway you could tell me the detentions of the garter spring, would 25mmx52mmx10mm work?

    ReplyDelete
  3. Excellent post. Thanks for sharing this. My 2005 TE 510 has just suffered this malady

    ReplyDelete