2005 GZ 250 idling problem

fairweatherrider · 07-15-2014, 04:52 PM

I have adjusted the throttle cables, and set the idle adjustment. It idles ok for a while, then speeds up. If I let out the clutch a little it slows down, then when I engage it, it speeds up again. It does this when I ride and stop. I noticed what looks like a crack in the intake tube so I ordered a new one. Does anyone know if I can replace it without removing the gas tank?

**jonathan180iq** · 07-15-2014, 05:57 PM

Are we talking about the tube between the carb and the engine?

You CAN remove it without taking off the tank. But, honestly, it's going to be much easier to just pull the tank and do your work without having to cram your fingers in tight little spaces.

Removing the tank takes all of 2 minutes. It's just 2 bolts, the gas line, and 2 vacuum hoses.

Water Warrior 2 · 07-15-2014, 06:08 PM

Quote:

Originally Posted by jonathan180iq

Are we talking about the tube between the carb and the engine?

You CAN remove it without taking off the tank. But, honestly, it's going to be much easier to just pull the tank and do your work without having to cram your fingers in tight little spaces.

Removing the tank takes all of 2 minutes. It's just 2 bolts, the gas line, and 2 vacuum hoses.

Absolutely remove the tank as Jonathan suggests. Why fight for a little finger room when you can create lots more and also improve the ease of the repair. Just the added visibility is a bonus.

fairweatherrider · 07-15-2014, 11:32 PM

I would like to thank you Jonathan, and Water Warrior for your reply. That's what I wanted to know. I will remove the tank. Plan to do it tomorrow or Thursday. I'm hoping that's the problem, the tube between the carb and engine. I'll check a few other things as long as I have the tank off.

**jonathan180iq** · 07-16-2014, 09:19 AM

They either age and crack around the intake neck, so a vacuum leak here isn't unheard of. I've not seen a crack on one, but it's withing the realm of possibility.

While you're in there, check out the condition of your vacuum hoses. If they are brittle, go ahead and replace them to avoid having to search out another vacuum leak in the future.

Water Warrior 2 · 07-16-2014, 09:24 PM

Vacuum hose should be available at any auto parts store. Take in the old hose to get the right diameter.

fairweatherrider · 07-18-2014, 01:17 PM

Well I changed the tube and O ring. What I thought was a crack was just a deep scratch possibly from some tool used before I bought the bike. I checked the hoses and they seem fine. I took it for a ride and it was still messed up. When I'm moving it's fine but when I stop it either speeds up or slows down so much it stalls. Not too happy.

**jonathan180iq** · 07-18-2014, 01:28 PM

Don't fret yet. This is going to be an easy fix once we nail it down. There is only so much that could be causing the vacuum leak, which is causing the hunting idle.

Check to see that the drain tube out the bottom of the air box is plugged. It is supposed to be plugged to keep unfiltered air out and to keep oil blow-by and other crap contained until the rider can properly drain it.

Take come WD40, while the bike is running and spray different parts of the intake system. Feel free to be liberal with the application. If you spray the WD40 over any area that is sucking in air and it shouldn't be, the idle will change. This can help you zone in on where the leak it, at best. And, at worst, you have a clean and shiny carb and hoses

Have you had the carb removed or worked on lately. There is a thin rubber diaphragm in the top of the card that often gets squeezed or pinched when people are messing with their carbs. (How me how I know. And ask me how 3 hours and some epoxy took care of it.

Start there - it'll tell you a lot. Let us know.

fairweatherrider · 07-20-2014, 02:58 PM

Well I tried the WD-40, checked the hoses again. The plug is on the end of the drain hose.While it was running okay I turned on the choke to see what would happen. It raced and when I turned the choke off it still raced until I turned off the ignition and restarted. Then it was fine again. I AM PUZZLED.

Water Warrior 2 · 07-20-2014, 09:14 PM

Quote:

Originally Posted by fairweatherrider

I have adjusted the throttle cables, and set the idle adjustment. It idles ok for a while, then speeds up. If I let out the clutch a little it slows down, then when I engage it, it speeds up again. It does this when I ride and stop. I noticed what looks like a crack in the intake tube so I ordered a new one. Does anyone know if I can replace it without removing the gas tank?

Just to clarify the wording. When you let out the clutch you are engaging the clutch. Pulling the lever in will disengage the clutch. Proper terminology will keep us and you on the right path.
Have a question. Did you have the irratic idle before adjusting the throttle cables??

07-15-2014, 04:52 PM	#1
fairweatherrider Member Join Date: May 2010 Location: Bristol,CT, USA Posts: 73	2005 GZ 250 idling problem I have adjusted the throttle cables, and set the idle adjustment. It idles ok for a while, then speeds up. If I let out the clutch a little it slows down, then when I engage it, it speeds up again. It does this when I ride and stop. I noticed what looks like a crack in the intake tube so I ordered a new one. Does anyone know if I can replace it without removing the gas tank? Login or Register to Remove Ads
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07-16-2014, 09:19 AM	#5
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	They either age and crack around the intake neck, so a vacuum leak here isn't unheard of. I've not seen a crack on one, but it's withing the realm of possibility. While you're in there, check out the condition of your vacuum hoses. If they are brittle, go ahead and replace them to avoid having to search out another vacuum leak in the future. Login or Register to Remove Ads
	0

07-20-2014, 02:58 PM	#9
fairweatherrider Member Join Date: May 2010 Location: Bristol,CT, USA Posts: 73	Well I tried the WD-40, checked the hoses again. The plug is on the end of the drain hose.While it was running okay I turned on the choke to see what would happen. It raced and when I turned the choke off it still raced until I turned off the ignition and restarted. Then it was fine again. I AM PUZZLED. Last edited by fairweatherrider; 07-20-2014 at 03:03 PM.
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07-15-2014, 05:57 PM	#2
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	Are we talking about the tube between the carb and the engine? You CAN remove it without taking off the tank. But, honestly, it's going to be much easier to just pull the tank and do your work without having to cram your fingers in tight little spaces. Removing the tank takes all of 2 minutes. It's just 2 bolts, the gas line, and 2 vacuum hoses.
	0

07-15-2014, 11:32 PM	#4
fairweatherrider Member Join Date: May 2010 Location: Bristol,CT, USA Posts: 73	I would like to thank you Jonathan, and Water Warrior for your reply. That's what I wanted to know. I will remove the tank. Plan to do it tomorrow or Thursday. I'm hoping that's the problem, the tube between the carb and engine. I'll check a few other things as long as I have the tank off.
	0

07-16-2014, 09:24 PM	#6
Water Warrior 2 Senior Member Join Date: Dec 2006 Location: Squamish B.C Canada Posts: 11,409	Vacuum hose should be available at any auto parts store. Take in the old hose to get the right diameter.
	0

07-18-2014, 01:17 PM	#7
fairweatherrider Member Join Date: May 2010 Location: Bristol,CT, USA Posts: 73	Well I changed the tube and O ring. What I thought was a crack was just a deep scratch possibly from some tool used before I bought the bike. I checked the hoses and they seem fine. I took it for a ride and it was still messed up. When I'm moving it's fine but when I stop it either speeds up or slows down so much it stalls. Not too happy.
	0

07-18-2014, 01:28 PM	#8
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	Don't fret yet. This is going to be an easy fix once we nail it down. There is only so much that could be causing the vacuum leak, which is causing the hunting idle. Check to see that the drain tube out the bottom of the air box is plugged. It is supposed to be plugged to keep unfiltered air out and to keep oil blow-by and other crap contained until the rider can properly drain it. Take come WD40, while the bike is running and spray different parts of the intake system. Feel free to be liberal with the application. If you spray the WD40 over any area that is sucking in air and it shouldn't be, the idle will change. This can help you zone in on where the leak it, at best. And, at worst, you have a clean and shiny carb and hoses Have you had the carb removed or worked on lately. There is a thin rubber diaphragm in the top of the card that often gets squeezed or pinched when people are messing with their carbs. (How me how I know. And ask me how 3 hours and some epoxy took care of it. Start there - it'll tell you a lot. Let us know.
	0