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Main Area => General GS500 Discussion => Topic started by: 1990dtgl98 on June 27, 2015, 02:18:17 PM

Title: Carbs unsyncing? (2002 issues)
Post by: 1990dtgl98 on June 27, 2015, 02:18:17 PM
Hey everyone!

Wealth of info on here. A little background. I bought my wife a '02 GS and have slowly been fixing issues with it to where she's comfortable actually riding it more than 20 minutes around the area.

I re-jetted it, as well as cleaned the carbs. However it still shudders and bogs down coming off from a stop (even with it revved to 5k and slipping the clutch). So I decided to check the carb sync. Did it the redneck spark plug pull and adjust ( as well as used a temp gauge to see the difference on sides), and found the right side barely changed when the plug wire was pulled where as the left side would stall the bike. Got it pretty close and ran it twice and it seemed to help, but not eliminate, the problem.

However with the I get a decent "tick" on the right side now. Almost sounds like a lifter tap on a car (worked on cars for 15 years, new to bikes, especially air cooled ones). Could it be a tight valve? Check shims? It's intermittent, but only seems to do it once its warmed up, and mainly at idle.

Secondly...checked it about an hour ago (synced the carbs about 2 months ago), and its back to the same as before. Pull right plug and no change, left plug stalls the motor. At idle the left side cylinder right by the plug runs roughly 220 degrees, right side is at about 170. How did it revert back to the same as it was in a 6 ride and 2 month span? Am I doing something wrong syncing these things up? It's basically exactly the same as when I first thought  I "fixed" it. Any idea as to what's going on? Am I syncing them wrong? Can I use loctite on the sync screw?

Thanks for the help in advance!

Title: Re: Carbs unsyncing? (2002 issues)
Post by: Big Rich on June 27, 2015, 04:58:52 PM
Check the valve shims first. Any change in intake / exhaust flow can change the flow thru the carbs (and change the carb sync).
Title: Re: Carbs unsyncing? (2002 issues)
Post by: Suzuki Stevo on June 27, 2015, 07:42:51 PM
Quote from: 1990dtgl98 on June 27, 2015, 02:18:17 PMAm I doing something wrong syncing these things up? It's basically exactly the same as when I first thought  I "fixed" it. Any idea as to what's going on? Am I syncing them wrong? Can I use loctite on the sync screw?

Thanks for the help in advance!

The screw isn't loose, the balance drifts over time, I usually sync once a year, I have bought new bikes that needed a sync as soon as I got them home.
Title: Re: Carbs unsyncing? (2002 issues)
Post by: bmf on June 28, 2015, 12:04:32 PM
+1 for valve clearances.

Sent from my SGH-I337M using Tapatalk

Title: Re: Carbs unsyncing? (2002 issues)
Post by: 1990dtgl98 on June 29, 2015, 07:22:25 PM
I'll check the clearances my next free weekend. Any recommendations to find a fast shim if something is off? Would like to have this done within 2 weekends.

My main concern is the apparent lack of chance or reverting back to the left side cylinder being the most used one without any work.

Basically, synced carbs (via ear and temp tests), rode about a dozen times in 6-8 weeks,  now reverted back to what is was in the beginning. Nothing (besides an oil change)  was done within this time frame (jets were last year). Is that still normal? Doesn't seem like I should have to sync carbs once a month?