Author Topic: What compression on your 500?  (Read 3157 times)

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Offline I_Duddits

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What compression on your 500?
« on: January 06, 2008, 04:04:40 PM »
I know my engine needs a rebuild but I'm running it while I rebuild my spare.
So on the bench (it's difficult to get a good kick on the starter) I get about 115psi. Is this going to be enough to start the beast? I reckon all assembled, when I can get a good purchase on the kick starter and kick it like I stole it, I should get a 135'ish out of it.

So is 115 to 135 gonna be enough?
How much is yours? I'm trying to get a feel for the average.

Offline CR480R

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Re: What compression on your 500?
« Reply #1 on: January 06, 2008, 08:57:22 PM »
Are you holdin the throttle open?

Offline I_Duddits

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Re: What compression on your 500?
« Reply #2 on: January 07, 2008, 03:14:27 AM »
Are you holdin the throttle open?
No throttle on the bike as yet, why would it make a difference to the reading?

Offline bigbellybob

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Re: What compression on your 500?
« Reply #3 on: January 07, 2008, 04:17:29 AM »
Are you holdin the throttle open?
No throttle on the bike as yet, why would it make a difference to the reading?


yes it will make a difference and 135psi is low even for a 125.
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IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

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Offline I_Duddits

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Re: What compression on your 500?
« Reply #4 on: January 07, 2008, 05:49:44 AM »
Are you holdin the throttle open?
No throttle on the bike as yet, why would it make a difference to the reading?


yes it will make a difference and 135psi is low even for a 125.

So how much should I be looking for then?

Offline bigbellybob

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Re: What compression on your 500?
« Reply #5 on: January 07, 2008, 06:13:13 AM »
some ware in the 190's
IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

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Offline I_Duddits

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Re: What compression on your 500?
« Reply #6 on: January 07, 2008, 06:50:17 AM »
some ware in the 190's
And that's with a BIG kick and the throttle fully open ?

Offline bigbellybob

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Re: What compression on your 500?
« Reply #7 on: January 07, 2008, 07:16:59 AM »
some ware in the 190's
And that's with a BIG kick and the throttle fully open ?

several big kicks and throttle fully opened dont stop kicking tell the gage stops moving
IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

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Offline bigbellybob

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Re: What compression on your 500?
« Reply #8 on: January 07, 2008, 07:18:09 AM »
also the green cases look awesome

what is the elevation your testing @

you can expect a 3-5% drop on the gage for every 1000 foot in elevation
« Last Edit: January 07, 2008, 10:21:12 AM by bigbellybob »
IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

sponsor
http://www.steelmx.com/

Offline I_Duddits

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Re: What compression on your 500?
« Reply #9 on: January 07, 2008, 01:42:44 PM »
also the green cases look awesome

what is the elevation your testing @

you can expect a 3-5% drop on the gage for every 1000 foot in elevation
I'm at sea level. I'm going to change pistons and barrel and see if I can up the compression.