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Main Area => General GS500 Discussion => Topic started by: VTNewb on August 08, 2004, 01:08:08 PM

Title: Causes of a high idle?
Post by: VTNewb on August 08, 2004, 01:08:08 PM
Now this isn't a GS series bike but its air cooled and carbureted so I'm just curious what causes this. The bike, when the idle is turned at a bout 1,200 will catch at 3 grand and stick if revved to that area or above. The carb boots are fine, done a wet test several times. The plugs read fine and the air filter is clean. Diaphragms are sealed properly and jets are at specification

BTW this is a Yamaha Maxim 700. I'm just wondering if someone could point out something for me to check.
Title: Causes of a high idle?
Post by: Jabba on August 08, 2004, 01:09:21 PM
set your idle screw at 1200 when the bike is fully warmed up
the best time to do this is after a long <more than 50 mile> ride on a hot day
Title: Causes of a high idle?
Post by: Jared on August 08, 2004, 02:11:16 PM
You have a lean condition....  Double check everything...vacuum leak.. mixture setting...float levels etc...

It has a factory exhaust on it?
Title: Causes of a high idle?
Post by: VTNewb on August 08, 2004, 02:29:59 PM
It is factory exhaust. I don't think it's lean though cuz my plugs vary from looking fine to a little black.
Title: Causes of a high idle?
Post by: Jenerator on August 08, 2004, 04:55:17 PM
Check my reply here: http://www.gstwins.com/forum/viewtopic.php?t=11321
Title: Causes of a high idle?
Post by: scratch on August 09, 2004, 11:34:31 AM
Is the screw over the vacuum balance tube there? Yamaha's Maxims, both the 700 and the 700X (5-valve Genisis motor), have a long tube at the back of the cylinder block, below where the carb boots mount; this is where this tube is. It balances/equalizes the vacuum between all four carbs. When you do a carb synch you have to use this four-section rod to seperate the vacuum between carbs, so you can balance the carbs properly. It's a special tool.