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Main Area => General GS500 Discussion => Topic started by: scratch on June 12, 2005, 12:21:47 PM

Title: Check this out...
Post by: scratch on June 12, 2005, 12:21:47 PM
I just finished a valve adjustment after 1000miles since my last at 24,000miles:
From:
Measured:
No. 1 Cyl / No. 2 Cyl
Ex: .05 / Ex: <.04 (< this is why I'm doin' the valve adjustment, I was waiting for shims to come in)
In: .08 / In: .04

Ex: 262 / Ex: 270
In: 255 / In: 260

To:
Ex: 260 / Ex: 265
In. 255 / In: 260

Measured:
Ex: .08 / Ex: .08
In: .08 / In: .04

And, when I perform the vacuum synch I find the No. 2 Cylinder drawing an inch more mercury than the left cyl. while before I had them synched perfectly.
Title: Check this out...
Post by: groff22 on June 12, 2005, 02:29:16 PM
Woa. Right over my head  :oops:
Title: Re: Check this out...
Post by: John Bates on June 12, 2005, 03:12:09 PM
Quote from: scratchI just finished a valve adjustment .................

Just curious, why did you change the exhaust shims when the tappet clearance was within spec. (0.03 - 0.08 )

:cheers:
Title: Check this out...
Post by: scratch on June 15, 2005, 12:54:08 PM
Sorry, I haven't replied for the last couple days, I've been in the hospital with food poisoning, or a stomach virus, or something.

The reason I changed the No. 1 exhaust was because I prefer to have my exhaust valves loose is to maximize the amount of time the valve has contact with the head to ensure more heat transfer from the vavle to the head, keeping the valve cooler and ensuring longer valve guide life.

Sorry, Groff, what all this means is that I did a valve check 3 weeks ago and while within spec, I was not comfortable running those valves that tight, so I ordered the shims I needed and performed a second valve adjustment 1000 miles later (3 weeks after the first one), instead of waiting another 4000 miles as suggested in our service manuals.
After the valve adjustment, I always re-synchronize my carburetors, because a valve adjustment can affect the amount of vacuum being drawn into a cylinder. In this case, it caused the right cylinder to draw more vacuum (or, more fuel/air mixture) than the other one, and would have worked harder than the other cylinder to produce power.
Title: Check this out...
Post by: John Bates on June 15, 2005, 01:58:48 PM
Thanks Scratch, I understand now.:thumb:

Hope you're feeling better.

:cheers:
Title: Check this out...
Post by: scratch on November 14, 2005, 12:37:24 PM
I've just finished the 28,000 mile tune and service and I didn't have to adjust any of the valves.

Measured:
Ex: .08 / Ex: .06
In: .06 / In: .04

Now, this time I pulled the carbs off and fiddled with them so I don't know how the vacuum was before, but they are now synchronized from idle to redline once again  :) , and boy, is the bike Sooo smooth!  :)
Title: Check this out...
Post by: pandy on November 14, 2005, 02:20:59 PM
Quote from: scratchbut they are now synchronized from idle to redline once again  :) , and boy, is the bike Sooo smooth!  :)
Duh....has nothing to do with synchronization...it's smooth cuz it's PURPLE!!!!!!!  :mrgreen:
Title: Check this out...
Post by: Alphamazing on November 14, 2005, 02:27:59 PM
After reading this I figured I might as well sync my carbs this weekend. Thanks for the idea!
Title: Re: Check this out...
Post by: scratch on May 30, 2006, 10:56:52 AM
I've just finished the 32,000 mile tune and service and I only had to adjust one valve.

Measured:
Ex: .08 / Ex: .04
In: .04 / In: .04

Ex: 260 / Ex: 265
In: 255 / In: 260

To:
Ex: 260 / Ex: 262
In. 255 / In: 260

Measured:
Ex: .08 / Ex: .08
In: .04 / In: .04

I didn't get to synch the carbs due to a sudden invitation to go fishing for my nephew's birthday.  I will be posting results for V8Pinto.
Title: Re: Check this out...
Post by: Kerry on May 30, 2006, 11:54:24 AM
Gotta love those odd-sized shims!  ( 2.62mm)  :thumb: