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  #1  
Old 01-12-2002
Bowls Bowls is offline
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Unhappy Auto Decomp.

I have an 02 YZ250f and was wondering if its possible to get a auto decomp conversion??? If so how much would it cost? if anyone just so happens to have prices thanks
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Old 01-12-2002
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WRDave WRDave is offline
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Havent exactly priced it myself, but it is around about $300 - $400 for the exhaust cam, and about 1 hours labour (assuming they can get to the engine), more like 2 hours if not.. But that is a bit of a ballpark figure. (round $500)

Dave
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Old 07-12-2002
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My dealer quoted me $250 odd for the cam but no stock till new year.
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Old 11-12-2002
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i ordered mine it is $250 plus 1hour to fit
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past rides 1980 TS185,1990 TS200R, 83 RG250, 83 Z250, 93 RM250, 97 KX500, 98 CBR900, 99 YZFR1 x 2, 00 Across, 02 TTR250, 98 TTR600, 02 WR250F, 03 GSXR1000, CT110, 04 YZFR1, 05 WR450F, 07 WR250F, 05 250EXC, 2008 GSXR1000, Grizzly 660
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Old 12-12-2002
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Can somebody tell me what an auto decomp does and if does what i thick why do u need it on a 250 . MUCH TO MY MATES DISBELIEVE, i can start his 426 without using the decomp lever. I,ve been able to do this since it was new, also can do the same on another mates dr350 but it is alittle tiered.

just kick the thing
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Old 12-12-2002
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hi dude cant answer for the 426 but i cant kick my 250 with out the decomp.
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past rides 1980 TS185,1990 TS200R, 83 RG250, 83 Z250, 93 RM250, 97 KX500, 98 CBR900, 99 YZFR1 x 2, 00 Across, 02 TTR250, 98 TTR600, 02 WR250F, 03 GSXR1000, CT110, 04 YZFR1, 05 WR450F, 07 WR250F, 05 250EXC, 2008 GSXR1000, Grizzly 660
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  #7  
Old 12-12-2002
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How the hell do ya start a 250 wif out using the decomp lever???
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Old 13-12-2002
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If you do the starting routine without using the decomp lever, you are risking breaking the kick start shaft. If your engine is in good nick and there is still a lot of compression, there will be a lot of force placed on the internal components of the starter mechanism when you push through TDC.

Wild horse
Using decomp opens the exhaust valves. Therefore when the engine gets to the compression stroke you can release the built up air in the cylinder.
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Old 13-12-2002
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i allways use the decomp lever anyway
I couldnt start it wif out it
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  #10  
Old 16-12-2002
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FastHakka FastHakka is offline
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Hmm.. I got a quote of $309 for the cam, no installation.

A while back my engine was down on compression due to leaking valves/ worn piston rings. I could start it without the lever but after rebuilding it I had to put my whole bodyweight on the kickstarter for about 5-7 seconds to push it through the compression stroke.
If you are starting a healthy motor without the decomp lever you will break something.

Wildhorse- to start the bikes without the auto decomp you need to find the compression stroke with the kickstarter, depress the manual decomp lever to push the motor just past the compression stroke, and then let the kickstarter back up to the top of its travel and kick it hard. If it doesn't start you go back and do it all again.
With an auto decomp you just kick it like a two stroke.
In the time you spend going through the drill once with the manual system you could kick the auto 3 or 4 times.
Another advantage of the auto is that when you stall under brakes coming into a corner, as soon as you let out the clutch the motor will fire right back up.
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