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Main Area => General GS500 Discussion => Topic started by: mike24 on December 15, 2005, 03:23:15 AM

Title: lowering RPM?
Post by: mike24 on December 15, 2005, 03:23:15 AM
hi,

my RPM on idle is 1500. how do i lower it? (pics might help)

thanks.
Title: lowering RPM?
Post by: sledge on December 15, 2005, 05:54:44 AM
Between the carbs is a a small vertical shaft with a circular handle. Its difficult to see but if you reach under you will feel it. Just turn it slightly till you get the required speed, think its 1200 max, can anyone confirm this?
Title: lowering RPM?
Post by: buzz on December 15, 2005, 05:54:51 AM
Look under the carbs. You should see a little white plastic nut. You can turn it by hand.
Title: lowering RPM?
Post by: JamesG on December 15, 2005, 05:55:27 AM
The question is why did your idle go up?

How many miles are on the bike? When did the idle go up? Gradually or just all of a sudden?

There could be a lot of reasons why the idle has gone up. From valve clearances going off to just the carbs needing a sync.

The direct answer to your Q is that its a PITA.  You have to reach between the hot engine and the airbox and turn a screw between the carbs. Taking the tank off helps.
Title: lowering RPM?
Post by: Badger on December 15, 2005, 08:24:05 AM
Quote from: sledgeBetween the carbs is a a small vertical shaft with a circular handle. Its difficult to see but if you reach under you will feel it. Just turn it slightly till you get the required speed, think its 1200 max, can anyone confirm this?
I'm not sure I understand why there would be a "max idle" limit...does the engine overheat if it idles too high with no airflow?  I was talking to someone who sets their idle much higher (admittedly on a liquid cooled bike) becuase he spends a lot of time in stop & go traffic and it's more convenient to not have to run up the throttle to move up 6 feet.  I think he said he keeps his RC51 idling over 2200.  I thought it was odd, but it made me curious.
Title: lowering RPM?
Post by: scratch on December 15, 2005, 09:03:24 AM
It would help if we knew what year model you have. Here's a picture of the idle screw for '89-'00 models: http://gstwins.com/forum/viewtopic.php?p=162473#162473
Title: lowering RPM?
Post by: sledge on December 15, 2005, 12:20:10 PM
The figure I quote for idle speed is something I think I remember reading somewhere in some GS related topic or manual. I dont think its a maximum figure as such, just the figure Suzuki quote and someone with a manual needs to confirm it but the true figure wont be far off. Highly tuned performance engines are not happy ticking over at low speeds, something to do with the cams and timing and I think and that may be a factor in the case of your mates RC51. However a stock GS will happily manage a steady tickover and be able to pull away cleanly at a much lower engine RPM than 2200, so why set it any higher than it needs to be. Think of all the wasted fuel, excessive noise and uneccesary wear to the engine and clutch.
Title: lowering RPM?
Post by: Roadstergal on December 15, 2005, 12:28:02 PM
Idle screw location and appearance is essentially unchanged up to current.
Title: lowering RPM?
Post by: scratch on December 15, 2005, 12:31:45 PM
Quote from: sledge...think its 1200 max, can anyone confirm this?
Yes, 1100-1200. Set after a good long ride. Edit: May be too low when cold, use throttle to keep up the rpm's.

RG - I was confused by the mention of little white knobs.
Title: lowering RPM?
Post by: Roadstergal on December 15, 2005, 01:00:14 PM
Ja, the newer ones have a little white plastic knob, but it's the same shape and in the same place.  Just adjust it with a glove on.
Title: lowering RPM?
Post by: calamari on December 15, 2005, 04:33:17 PM
ride for a while. when bike is warm, reach the white knob and turn it to lower rpm's. put on glove to avoid burning your hand, unless you are manly enough and do it bare skin like I do.
Title: lowering RPM?
Post by: buzz on December 16, 2005, 07:14:10 AM
QuoteRG - I was confused by the mention of little white knobs.

Sorry I will be more careful about mentioning little white nobs. :roll: