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  • 1 Post By heidenberg
  • 1 Post By Taffy
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December 20th, 2020, 09:20 AM   #1
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Joined: Nov 2001
From: Long Beach, CA

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I Ride:
2000 FC 501 Auto decompression cam spring

Please look at the attached photo after reading below.

I had the bike apart forever after breaking an exhaust pivot arm. When I put it back together I think I either did not set the auto decomp spring correctly or it is broken.

With engine off the spring should always keep the auto decomp cam tight against the cam shaft, correct?

It only opens up by centrifugal force when spinning up, correct?

Note, the pictures are with the cam lobes pointing up, so not at TDC.

Also, would this make bike impossible to start? I have clean carb and good spark

Help is appreciated, thank you!
Attached Thumbnails
2000 FC 501 Auto decompression cam spring-20201220_084503_resized.jpg   2000 FC 501 Auto decompression cam spring-20201220_084556_resized.jpg   2000 FC 501 Auto decompression cam spring-20201220_084701_resized.jpg  

Last edited by Hakan; December 20th, 2020 at 09:36 AM.
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December 20th, 2020, 04:49 PM   #2
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Joined: Jul 2019
From: southwest

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I Ride: 99 FE501e, FX600e, FC501
Yes the spring needs to be wound so the centrifugal sledge is tight against the cam and snaps back when pulled. Not too tight or it won't be able to swing.

This will in fact make the bike damn near impossible to start
Thanks from Hakan

Last edited by heidenberg; December 20th, 2020 at 04:54 PM.
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December 21st, 2020, 01:29 AM   #3
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From: Ely, England

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I Ride: Husaberg FE501e 2003
you need to spend a few dollars there if you can afford it. those valve springs are way too hard. go to dual springs. already, your inlet valves will be distorted.

if you have the half moon decomp then do as above requests. if you have the rowing boat decomp - forget it. they are too soft.

the dilemma is that to upgrade to the 2004 decomp, you need a steel cam sprocket and the end shoulder of the cam grinding down 2mm. almost too much to ask you to spend that when you're ona budget.

the w/p impeller looks like dog shit too.

don't clean your carb, get an easy start kit. renew, refresh, upgrade.

Thanks from Hakan
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  Husaberg Forum > Mechanical and Technical > Mechanical

2000, 501, auto, auto decompression, cam, decompression, spring

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