Removing the Automatic Compression Release

[klrman]

Removing the Automatic Compression Release

Has anyone removed the Automatic Compression Release of the exhaust camshaft?
Just wondering if I should take it off since it looks like it is not needed anymore now with the electric starter. Looks kind of flimsy anyway if you ask me.

 

[Kuzzy]

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If it's not broke why fix it? They must have left it on for a reason. It would have been less cost to Kawi to build the engine minus these parts so it must do some good. Save your starter and leave it alone. (IMO)

 

[klrman]

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I have seen "leftovers" in the past on other engines and this just looks like one
of those. Maybe it will create less drain on the battery by releasing some compression, but I just get this "itch" to remove it and other than that, it seems like a piece of useless metal.

 

[Island Hopper]

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If it's anything like on my bike, the autodecomp is still working upon startup to reduce strain on your electric starter. Without the decomp in place your starter at times may not be able to spin the engine.

 

[klrman]

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I was just thinking about that too that it helps the starter. I was just was curious if anyone had actually taken it off and noticed any ill effects.

 

[klrman]

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Someone mentioned on the web that it is possible to make a mistake
reading the exhaust valve clearances if the Automatic decompression release
gets in the way of the measurements. Can anyone eloborate on this?
I just set my clearances, but I am a little confused as to how the ADR can get in the
way unless I am missing the obvious? That would be a Bummer after I just bolted everything back together.

 

[Island Hopper]

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I think I read something about that if you spin the engine backward to get to TDC that it could engage the autodecomp and give you a false reading. Dont know for sure but to play it safe I would spin the engine forward to arrive there and maybe a minor wiggle back to hit the mark if you slightly pass it.

 

[klrman]

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That would explain why on Mark's KLR website, he stresses to turn the engine counter clockwise when finding TDC. I was always wondering why he stressed that so much. Thought it must have had some importance. Thanks for that Island Hopper. Always an uneasy feeling if I did not do something correctly

 

[joker650]

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The auto decomp activates when the engine is cranked over. It releaves strain on the starter motor , this prevents wear on the motor and drive gears and a lower current draw from the batterie due to an easier turning motor. The starter may not have enough powet ot turn the engine past full compression, it may even back-fire and cause damage to the starting system.

If it's falling appart I would fix it but I wouldn't remove it.

 

[klrman]

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That makes alot of sense. Don't know why I was so eager to get rid of it. It really does look flimsy though, but I guess it holds up as I have not heard many issues
with it.

 

[ardyjay]

I removed mine because it grenaded, and it worked fine- until I overhauled the top end. Now I have to bump it past top centre on compression to get enough spin to get it to start.
Anyone have a burned up exhaust cam, engine or whatever, they want to sell. I'm putting it back on.

 

[DirtClunker]

I had a 08 KTM EXC and they had factory flaw - the auto decomp backwards and would not work. Starter would barely turn it over and would eat batteries. Yes auto decomp is needed for electric start too.

 

[offworlder]

I had a 08 KTM EXC and they had factory flaw - the auto decomp backwards and would not work. Starter would barely turn it over and would eat batteries. Yes auto decomp is needed for electric start too.

My 2012 Beta 450 RR had this issue. The brains at the factory completely screwed that up. IMPOSSIBLE to kickstart, and repeated attempts to e-start resulted in a dead battery. A pile of $$$ later, and its fixed (grrrrrr !)

Note the reversed position of the two decompression cams: