Very High Idle

[teufel_hunden_rider]

Hello everyone. I'm new to the site and new to riding motorcycles. I have only had my 2000 Suzuki gz250 for a few months. But ever since I got it it has been idling very fast once it warms up. Typically it runs well once I start it for the first time that day but after a matter of minutes it idles and runs very high. If I take it past 50mph it goes really high. I turned the black cylindrical, screw like, throttle adjustment that is right next to the throttle handle all the way to the low end as far as it went but that just lets me start it in a somewhat normal rpm but it creeps back up quick.

I've got a few months to fix up my bike before I go to boot camp for the marines and I want to leave a well running bike for my girlfriend to start learning how to ride on since I'm going to get a new bike when I get my first duty station. Any help you guys can give me would be very much appreciated. I would love to get it fixed before I go so I can teach her a bit myself before she does STARS.

[jonathan180iq]

The cylindrical thing beside the throttle handle isn't the idle adjustment. There are some gross throttle adjustment knobs there, but that's for taking the slack out of the throttle cable.

Are you using choke when you start the bike? Are you turning the choke off after it's started?

Let the bike get warm, and then turn the actual idle adjustment screw until you reach a stable and low RPM at idle. "chugchugchugchugchugchug" It should not sound like a constant "chuuuuuuuuuuuuuuug", if that makes sense. Listen to some of the videos on YouTube of other GZs to get it dialed in, since we don't have a tach or anything.

If, after adjusting the proper idle adjustment screw it's still not working for you, then we can diagnose what some other possible issues might be.

Never fear, though. This will be an easy one.

PS: Adjust this thing:

Ignore the red arrows. It's that white knob.

[blaine]

Turning the white knob counter clockwise increases the idle,clockwise decreases it.

[alantf]

Originally Posted by blaine

Turning the white knob counter clockwise increases the idle,clockwise decreases it.

???? Screwing it in (clockwise) increases the speed. Screwing it out (anticlockwise) slows it down. This is because, screwing it in, pushes the throttle quadrant, thus opening the throttle further.

[blaine]

Originally Posted by alantf

???? Screwing it in (clockwise) increases the speed. Screwing it out (anticlockwise) slows it down. This is because, screwing it in, pushes the throttle quadrant, thus opening the throttle further.

Yes....But to turn the knob in you have to turn counter clockwise (Right hand threads)

:cool:

[JohnC]

Originally Posted by blaine

Yes....But to turn the knob in you have to turn counter clockwise (Right hand threads)

:cool:

Only if you live in the southern hemisphere.... "Lefty loosey, righty tighty..."

[jonathan180iq]

...just turn it whatever way you need to until you feel the idle move up or down, and then keep going whichever direction you need.

[teufel_hunden_rider]

That's very informative, thank you. I will go to the grocery store in a few minutes and try that out. Hopefully it fixes the problem. Thank you so much for all of your fast responses.

[alantf]

Originally Posted by blaine

Yes....But to turn the knob in you have to turn counter clockwise (Right hand threads)

Errrrrr....No you don't. Grab yourself a screwdriver, and try to put a screw into a piece of wood. Then tell us which way you had to turn the screw. At the same time, find a clock to look at, so you know which way is clockwise. :whistle:

[teufel_hunden_rider]

Hey that worked great. Went to and from store with a nice purr that I could actually count the rpm and not just hear a constant roar. I'll take it out on the freeway next week to fully check it but it seems good so far. Thanks guys for this simple fix and the picture made it super easy.