Temporary high idle at stop lights

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Madbuffalo
To the on ramp
Posts: 463
Joined: Thu Feb 17, 2011 8:55 pm
Country: USA
Suzuki 2-Strokes: GT750
Location: Grand Rapids, Michigan, USA

Temporary high idle at stop lights

Post by Madbuffalo »

I don't know how else to put it other than that. After cruising (typically low throttle opening) I pull in the clutch and coast to a stop light and the bike (GT750M) will idle high at about 2,200 rpms for about 20 seconds and then calm down to 1,500 rpms (where I have it set). Is this normal or does it indicate a problem with my fuel mixture? The bike has chambers, has been re-jetted (+7.5 mains, otherwise stock), and had an engine rebuild last winter and I honestly can't remember if it was doing it before I did the work.
No really... it's supposed to smoke.

1974 Suzuki Nomad 340
1975 Suzuki GT750 Waterbuffalo
2018 Kawasaki Z900rs
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Coyote
Moto GP
Posts: 3404
Joined: Tue Oct 21, 2008 2:41 pm
Country: USA
Suzuki 2-Strokes: GT550x2, GT750, GS1000
Location: Tulsa, Oklahoma

Re: Temporary high idle at stop lights

Post by Coyote »

I had the exact same problem on my 550. You need to go +1 or +2 on your pilot jets. I had to go all the way to +3 on mine before the symptom finally disappeared. I am running chambers and pods.
I was born with nothing and still have most of it left.

.
1978 GS1000C
1976 GT550 ongoing money pit.
Madbuffalo
To the on ramp
Posts: 463
Joined: Thu Feb 17, 2011 8:55 pm
Country: USA
Suzuki 2-Strokes: GT750
Location: Grand Rapids, Michigan, USA

Re: Temporary high idle at stop lights

Post by Madbuffalo »

Thanks Chris. I figured as much but just wanted to be sure before removing the carbs to switch the pilots. Suzuki sure didn't make it easy to change jets did they. My '00 dirt bike was designed to change jets with the carb still in the bike but i guess nobody thought of that back in the 70's :(
No really... it's supposed to smoke.

1974 Suzuki Nomad 340
1975 Suzuki GT750 Waterbuffalo
2018 Kawasaki Z900rs
User avatar
Coyote
Moto GP
Posts: 3404
Joined: Tue Oct 21, 2008 2:41 pm
Country: USA
Suzuki 2-Strokes: GT550x2, GT750, GS1000
Location: Tulsa, Oklahoma

Re: Temporary high idle at stop lights

Post by Coyote »

Yes, those carbs are a major PITA. It's about a 6 hour job just to change the needle clip position. The BS carbs on the 750 are a lot easier to deal with. Just pop the top, lift out the diaphragm and slide, change the clip position and drop it back in.
I was born with nothing and still have most of it left.

.
1978 GS1000C
1976 GT550 ongoing money pit.
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