Power loss

1Rogue · 05-21-2007, 03:24 PM

Hey guys,
Thought I would see if anyone had any ideas on this.

When I have been riding the GZ a little while and I get the appx. 45-50 mph the bike starts occasionally losing power for a split second. It will come right back strong and I don't hear any unusual noises, it is like it justs skips out for a split second. Any thoughts on what may be the problem?

Thanks for all help!

**jonathan180iq** · 05-21-2007, 04:38 PM

Does this happen during acceleration (opening the throttle) or just while cruising?

Badbob · 05-22-2007, 05:42 AM

It could be electrical. A bare wire or loose connection that is only a problem when there is more vibration causing a weak or no spark for a short time.

How long has it been since you changed your spark plug. My GZ250 is very sensitive to this. The plug will look fine but not work very well.

1Rogue · 05-22-2007, 09:28 AM

Quote:

Originally Posted by jonathan180iq

Does this happen during acceleration (opening the throttle) or just while cruising?

I think it is happening more when I am increasing throttle.

As for the spark plug, I was told it was changed shortly before I got it, but that is something I will check.

**jonathan180iq** · 05-22-2007, 10:49 PM

If this happens while you;re accelerating, I'd think it was a problem with jetting. Did you buy this bike used? If not, where are you located? If someone tampered with the intake or something they could have made minor adjustments to the mid-range jetting that are not allowing proper fuel flow.
If your bike is stock, you might simply have a problem with the altitude where you live.

Aside from that, you may just need to clean your carbs out. Some old gunk could be holding the little moving parts back or gunking up some flow passages.

All gas has detergents in it. These detergents leave residues inside the carb that will collect if the bike ever sits for awhile or isn't used regularly.

Let me know,
Jonathan

1Rogue · 05-22-2007, 11:43 PM

I did get the bike used but the previous owner only did basic maintenance on it. Oil change, front brake change, brake fluid fill that kind of stuff. He said he did not know enough about motors to mess with anything else other than basic and did not have any modifications done. He rode it regularly until he bought his new Shadow 750 so it didn't sit for any length of time and it has about 4300 miles on it.

I am located just outside of Dallas, TX and the previous owner was in Ft. Worth, so I don't think it is a problem with altitude. He did tell me he was starting to notice something like what I am getting. I am a new rider and until recently I have been riding in lower speed areas getting comfortable with the bike. It is just in the past week or so that I have getting on larger roads with a little higher speeds. I did not get this problem at the lower speeds. It is only when I get in the area of 45-55 that it happens. I was trying to pay more attention tonight when I was riding and it did seem to do it some when I was holding speed and not really throttling up.

You mentioned it might be gunk in the carb. Would running some kind of fuel cleaner through help get any possible gunk out, or will I need to breakdown the carb to clean it? I was also thinking it might possibly be clogged fuel filter. I was going to look and see what it would take to get to that.

I am waiting on the parts to get in but I am going to do the needle shim and 16t sprocket change when they do. Will the shim affect it any or with that area of the carb open could I maybe spray a cleaner or something in that would help at that time?

Thanks for all your help!

Dupo · 05-23-2007, 01:29 AM

If you want to try to clean out the fuel system/carb ... pick up a can of SeaFoam at an auto parts store. Read the directions carefully and only put in whatever oz per gallon. Run that tank down and that will clean out your carb/jets fuel system better than anything else.

**jonathan180iq** · 05-23-2007, 04:18 PM

If it happens more when cruising then I'd say that it's not jetting. It sounds more like a gunk problem. You may just be getting occasional chunks stuck in some important places. (these aren't really CHUNKS, but you know what I'm saying.)

Run some SeaFoam as Dupo suggested and let us know what happens.

Take care,
jonathan

racinnuts · 05-23-2007, 09:30 PM

I have a similar, but more serious power loss problem. Occasionally my bike will lose power while running down the road at a steady speed. After pulling over it will idle steady and smooth, but will still not have power uned thottle. After cutting off the ignition and restarting the engine it will run fine This may happen two or three times in one day, or go two or three month between mishaps. Anyone have an idea?

racinnuts

**jonathan180iq** · 05-24-2007, 04:23 PM

That sounds pretty wierd. Only time that I've ever had anything happen like this was when I let my Ninja sit for about 3 months and I didn't prep it. However, after it stopped running completely one time I just drained the gas tank and cleaned the carbs and I never had another problem.

I'd suggest the usual; carb clean, maybe a valve adjustment, and check for any leaks or faulty hoses. It's also possible that BadBob's suggestion might be happening to you.

Removing the carbs and studying them really helps you understand how they work and it gives you an opportunity to inspect for possible worn parts.

Sorry I can't be of more help.

Take care,
Jonathan

05-21-2007, 03:24 PM	#1
1Rogue Member Join Date: May 2007 Location: Sachse, TX Posts: 41	Power loss Hey guys, Thought I would see if anyone had any ideas on this. When I have been riding the GZ a little while and I get the appx. 45-50 mph the bike starts occasionally losing power for a split second. It will come right back strong and I don't hear any unusual noises, it is like it justs skips out for a split second. Any thoughts on what may be the problem? Thanks for all help! Login or Register to Remove Ads
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05-22-2007, 05:42 AM	#3
Badbob Senior Member Join Date: Aug 2006 Location: Tallahassee FL Posts: 945	It could be electrical. A bare wire or loose connection that is only a problem when there is more vibration causing a weak or no spark for a short time. How long has it been since you changed your spark plug. My GZ250 is very sensitive to this. The plug will look fine but not work very well. __________________ My GZ250 Blog Facebook Pinterest Google+ Tumblr YouTube Lumber Jocks Login or Register to Remove Ads
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05-22-2007, 10:49 PM	#5
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	If this happens while you;re accelerating, I'd think it was a problem with jetting. Did you buy this bike used? If not, where are you located? If someone tampered with the intake or something they could have made minor adjustments to the mid-range jetting that are not allowing proper fuel flow. If your bike is stock, you might simply have a problem with the altitude where you live. Aside from that, you may just need to clean your carbs out. Some old gunk could be holding the little moving parts back or gunking up some flow passages. All gas has detergents in it. These detergents leave residues inside the carb that will collect if the bike ever sits for awhile or isn't used regularly. Let me know, Jonathan Login or Register to Remove Ads
	0

05-23-2007, 01:29 AM	#7
Dupo Senior Member Join Date: Aug 2006 Location: Allentown, Pa Posts: 1,255	If you want to try to clean out the fuel system/carb ... pick up a can of SeaFoam at an auto parts store. Read the directions carefully and only put in whatever oz per gallon. Run that tank down and that will clean out your carb/jets fuel system better than anything else. __________________ Photography Gallery *updated url - new site! Motorcycle Blog Facebook
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05-21-2007, 04:38 PM	#2
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	Does this happen during acceleration (opening the throttle) or just while cruising?
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05-22-2007, 11:43 PM	#6
1Rogue Member Join Date: May 2007 Location: Sachse, TX Posts: 41	I did get the bike used but the previous owner only did basic maintenance on it. Oil change, front brake change, brake fluid fill that kind of stuff. He said he did not know enough about motors to mess with anything else other than basic and did not have any modifications done. He rode it regularly until he bought his new Shadow 750 so it didn't sit for any length of time and it has about 4300 miles on it. I am located just outside of Dallas, TX and the previous owner was in Ft. Worth, so I don't think it is a problem with altitude. He did tell me he was starting to notice something like what I am getting. I am a new rider and until recently I have been riding in lower speed areas getting comfortable with the bike. It is just in the past week or so that I have getting on larger roads with a little higher speeds. I did not get this problem at the lower speeds. It is only when I get in the area of 45-55 that it happens. I was trying to pay more attention tonight when I was riding and it did seem to do it some when I was holding speed and not really throttling up. You mentioned it might be gunk in the carb. Would running some kind of fuel cleaner through help get any possible gunk out, or will I need to breakdown the carb to clean it? I was also thinking it might possibly be clogged fuel filter. I was going to look and see what it would take to get to that. I am waiting on the parts to get in but I am going to do the needle shim and 16t sprocket change when they do. Will the shim affect it any or with that area of the carb open could I maybe spray a cleaner or something in that would help at that time? Thanks for all your help!
	0

05-23-2007, 04:18 PM	#8
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	If it happens more when cruising then I'd say that it's not jetting. It sounds more like a gunk problem. You may just be getting occasional chunks stuck in some important places. (these aren't really CHUNKS, but you know what I'm saying.) Run some SeaFoam as Dupo suggested and let us know what happens. Take care, jonathan
	0

05-23-2007, 09:30 PM	#9
racinnuts Junior Member Join Date: May 2007 Posts: 5	I have a similar, but more serious power loss problem. Occasionally my bike will lose power while running down the road at a steady speed. After pulling over it will idle steady and smooth, but will still not have power uned thottle. After cutting off the ignition and restarting the engine it will run fine This may happen two or three times in one day, or go two or three month between mishaps. Anyone have an idea? racinnuts
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05-24-2007, 04:23 PM	#10
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	That sounds pretty wierd. Only time that I've ever had anything happen like this was when I let my Ninja sit for about 3 months and I didn't prep it. However, after it stopped running completely one time I just drained the gas tank and cleaned the carbs and I never had another problem. I'd suggest the usual; carb clean, maybe a valve adjustment, and check for any leaks or faulty hoses. It's also possible that BadBob's suggestion might be happening to you. Removing the carbs and studying them really helps you understand how they work and it gives you an opportunity to inspect for possible worn parts. Sorry I can't be of more help. Take care, Jonathan
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