Bike wont start!/ fouling plugs?

[feltner58]

My name is Dan I'm new to the forum, I just recently bought a 2001 gz250 with 6k on it, it hadnt been ridden much, I believe the previous owner let it sit for a good while, so like anything I buy that hasnt been run alot, I brought it back to life, ran seafoam through the fuel system, changed the oil and filter as well as the air filter, got the idle set just right and had it running great started right up everytime didnt even need the choke. But last week I rode it to work and when I got home I parked it in the garage. That next morning I went to start it to ride to work again, and it wouldnt start, the starter just kept turning over and over. so I used the choke and it still wouldnt start. I started to look the bike over to see if there was anything out of place, and i noticed that where the choke cable goes into the carb there is a little metal elbow with a rubber gromet that holds the cable in the carb and this whole assembly had come out of the so much that I could see the actual choke cable. so I put it back in as far as it would go and turned the choke off. tried to start it again, no start. so then I took the plug out and looked it it, it was a little black but not overly dirty, I literally wiped it off with my thumb and put it back in and it started right up like nothing was wrong. This would lead me to believe that the bike is fouling plugs or not getting a strong spark. I did accidently run the bike with the choke on when i first got it but it didnt foul the plug and that was over a month ago and it hasnt had any problems until now, it keeps not wanting to start after a undetermined amount of time, the battery is not the original or manufactures recommended size and power (all the lights stay lit and the starter never starts to slow down so no obvious problems with the battery) I dont know if that could be it, I modified the exhaust but I dont think that should effect the starting aspect or the spark plug..............should I get a new plug maybe thats it, a new battery? new coil? Im a technician at goodyear so Im pretty mechanical but bikes arent really to familiar to me... Please help I love riding this bike its my favorite bike Ive ever owned and I would like for it to run for some time to come.

[blaine]

Welcome to the forum.I would bet that after you used the SeaFoam that the plug is fouled and you need a new one.I would also have the battery checked .A good investment ia a 2a trickle charger.
:cool: :)

[JWR]

If you can, use booster cables on it the next time it does not start.

The battery may be good, but see if a little extra is needed.

[blaine]

If you can, use booster cables on it the next time it does not start.

The battery may be good, but see if a little extra is needed.
Just make sure that the vehicle that you are boosting from is shut off.If you leave it running you will fry the electronics.
:) :2tup:

[feltner58]

Ill try a new plug and do a load test on the battery, the gap is .6mm to .7mm correct?

[BillInGA]

Welcome aboard!

[blaine]

Ill try a new plug and do a load test on the battery, the gap is .6mm to .7mm correct?
Yes,that is correct,or 0.024 - 0.028. :cool: :)

[Water Warrior 2]

After the bike has been parked all night or a number of hours you will need to use the choke to start the fire in the GZ. You probably flooded the engine and fouled the plug at the same time. A new plug is probably in order.

[mrlmd1]

The bike needs the choke to start first thing in the morning and if it's sitting for many hours in between starts. Do not apply any throttle when you try and start it - you will flood it. There is this macho thing to start the bike without the choke but that's not how it is designed and is wrong. That's only for a warm engine or if it's really hot outside. Put the choke at least 1/2 -3/4 the way up and then start the bike and slowly turn it down as the idle speed increases or within a minute or two or a mile or so of riding.
You probably flooded it trying to start it without the choke and cleaning off the plug and opening up the cylinder helped it start. Changing the plug is OK and maybe a good idea, but if you run it, it may not need that. By wiping it off with your thumb you did nothing to clean the contacts where the spark arcs, so the plug is not the problem.
FYI - the idle speed should be set when the engine is fully warmed up.
Get yourself an owner's manual and read it, especially about starting and troubleshooting. You can download one off here.
Get yourself a 2 amp trickle charger/battery maintainer or whatever you want to call it, attach the pigtails to the battery so you can easily hook it up when you need it. There also is probably nothing wrong with your battery so don't go replacing things here and there in a shotgun approach to solve this problem.The only way you know if a battery is bad is to fully charge it and have it load tested, but if you charge up the battery and the bike starts, the battery is fine. It will not charge at idle speed, the bike needs 2500-3000 rpm to put out any decent charging current, so if you leave it sit at idle for an extended period of time, like 10 min, you are depleting the battery more in starting it and running the lights, etc, then you are replacing into the battery. It needs to be run on the road to charge the battery.

What did you do to "modify" the exhaust?

[feltner58]

2 inch chrome drag pipes, no baffle......I know the battery is fine did a load test at the shop and the previous owner had the gap way to open on the plug, I cleaned the plug and put it back in......seems to be running fine now I made the mistake of opening the throttle up with no choke when Ive been trying to start it, like you said I think that was the issue. Motorcycles are new to me so I appreciate the help........on another note what is the average lifetime of the gz motor, how many miles?

[JWR]

..on another note what is the average lifetime of the gz motor, how many miles?


A rider in Nashville had over 30,000 miles on his, then made a 9,000 mile Alaska trip.
Far as I know he is still riding it.

[Water Warrior 2]

A GZ engine will last a long time if you treat it like a friend and don't abuse it. You can not run them wide open throttle and expect a long life engine. Proper maintenance and some TLC will get you a long way on a GZ.

[mrlmd1]

Glad you got it running and the problem is resolved. Most of the time it's operator error, not the bike's fault.
Every 3 or 4 tankfills, put 1 oz/gal of gas of Seafoam or Berryman/s B12 Chemtool (1/3 the price) into the mix, and your carb will stay clean and you won't have to fuss with that.
Your bike should outlast you with oil changes and valve checks at the recommended intervals and the only other maintenance thing you will have to do is renew brake pads and tires when needed. You should think about replacing your tires if they are the originals as they are 10 years old and the rubber gets hard and brittle and doesn't have the same grip on the road as fresh ones. Check the date stamp on the sidewalls in a little rectangular box, it gives the week and year of manufacture and if they are more than 6-7 years old, replace them for safety. You will also need new tubes and probably rim strips inside the wheels.There are innumerable threads on here about replacement tires.

[feltner58]

sometimes it sounds like it misses once or twice at idle, but Ive heard that this is just because it has a carburetor and one cylinder, I actually didn't notice it until my buddy told me to listen really closely, is it just me being paranoid or could it be an actual problem, its only at idle and you really have to pay attention to hear it

[Water Warrior 2]

The miss every so often is okay. Just a side effect of a single cylinder and lean jetting. Don't sweat it. Always buy your gas from a major chain as they tend to have a better quality refining process and additives that will keep the carb system a little cleaner.

[blaine]

I don't think it's a problem.Just keep some SeaFoam in the fuel for the next couple of tanks and I think you will be fine.
:cool: :)

[feltner58]

Now its running at a really high idle even when the idle screw isn't even touching the throttle its almost like its running with the choke on but I have the joke completely off please help, is my choke sticking this is driving me nuts

[bonehead]

Make sure your throttle cables are'nt binding anywhere and are moving freely thru the cable housings.

[jonathan180iq]

All those cables do need to be lubed once in a while to make sure they don't bind or stick. Since your bike is now a decade old and it didn't get used that much, I'd say it's time for a good old fashioned "Maintenance Saturday!"

For lubing cable, I personally prefer the tiny oil feed from bicycle cable lubes, which you can find at Wal-Mart for about $4.58.

Properly adjusting throttle play and clutch cable tension should be something you do at this time, since I'll bet money your high idle is caused by a sticky cable.
(Bookmark this service manual link. It's a God-send.)

http://www.gz250bike.com/gzfiles/manualserviciogz250.pdf

Just reading the words, it can sound complicated to a beginner but it's really not.

Basically, all you are doing is loosening a lock-nut, twisting the adjuster one way or another to set proper tension/play, and then retighten the lock-nut to hold everything in place.

It really should only take maybe 10 minutes total to do both. Also, don't freak out when you realize you don't really know how to gauge 1/8" of play or whatever. Don't get caught up in the numbers. Just snug it up a bit. Then shoot some lube down under the cable covers and you'll be set.

Good luck.

EDIT: One more thing, with straight pipes coming off that little 1 cylinder, you might want to have a mechanic friend make sure it's properly been jetted. Lots of people get the jetting part wrong and then wonder why their bike doesn't act the same after they put new pipes on...

[feltner58]

Where would it most likely be sticking it only idles high after I give it gas, could it be in the carb

[blaine]

Where would it most likely be sticking it only idles high after I give it gas, could it be in the carb

Possible,but not likely.As stated you have a cable binding.When you say"it only idles high after i give it gas" reinforces that.If you unhook the cables at the carb,you should be able to tell which cable is binding.Also you will be able to see if the bike will idle & rev freely without the cables hooked up, eliminating the carb as the problem.
:) :cool:

[Water Warrior 2]

What Blaine said. You might also want to check for a vacuum leak. That can give you a fast idle too.

[feltner58]

Removed both throttle cables, throttle is disabled, stills idles way high but only when i turn the throttle, choke sticking maybe? help

[blaine]

Removed both throttle cables, throttle is disabled, stills idles way high but only when i turn the throttle, choke sticking maybe? help
Did you check for a vacuum leak? Just unhook the choke and try it, its possible that it may be sticking.
:) :cool:

[alantf]

Removed both throttle cables, throttle is disabled, stills idles way high but only when i turn the throttle,

If you removed both throttle cables, and disabled the throttle, how can you turn the throttle grip & make it work???? :cry:

[blaine]

Removed both throttle cables, throttle is disabled, stills idles way high but only when i turn the throttle,

If you removed both throttle cables, and disabled the throttle, how can you turn the throttle grip & make it work???? :cry:
I think he means when he revvs it from the side of the carb.
:2tup: :cool:

[feltner58]

There is still a throttle directly on the carb

[alantf]

Ah....... My mistake :blush:

[feltner58]

Any ideas of what it may be?

[alantf]

It would appear to be something sticking in the carb. How's your skills at stripping the carb? Or would you be happier letting the shop do it for you? Either way, it seems like it needs doing straight away. :)

[feltner58]

removed the choke, still doing it, are there vacuum hoses i only see one that could potentially be a vacuum?

[Water Warrior 2]

I wonder if the rubber boots on each side of the carb are tight. Check for loose clamps holding the carb in place. I can't remember if there are 2 or 1(intake and discharge sides of the carb)but some one will chime in to correct me.

[feltner58]

took the carb off stripped it cleaned all the needles and passages with carb cleaner and blew them out with air, reassembled the carb and put it back on hooked everything up and its still doing it.........what could it be now, its really starting to get annoying I want to Ride!!?????

[blaine]

There are two clamps,one on each side of the carb.There is only one vacuum hose to check.Starting to look like the carb will need to come off the bike.On the bright side,you done things step by step,eliminating problem spots as you go.
:) :cool:

[feltner58]

I already took it off and cleaned it all out, both clamps are tight all hoses are tight, vacuum hose is tight.......Could it be the float?

[blaine]

I already took it off and cleaned it all out, both clamps are tight all hoses are tight, vacuum hose is tight.......Could it be the float?
If the float was set to high,the bike would flood,plus you would see fuel comming out the over flow.When you had the carb off,did you notice if the throttle plate in the carb was closing tight when you snap the throttle? Also have you checked your air filter to see if it's clean?
:??: :)

[feltner58]

no I didnt really look at it to closely, I did notice some build up around the throttle plate, could that be it?

[Water Warrior 2]

no I didnt really look at it to closely, I did notice some build up around the throttle plate, could that be it?
That could be it. The throttle plate may be hanging up on the deposits just enough to hold it rather than letting it close more to an acceptable idle. Oh yeah, before I forget. Did anyone mention the air filter has to be removed to check it. Reason being the air flows from the inside to the outside of the filter. Opposite of what we normally find with an air filter. If it is really dirty on the inside you can tap it on the floor to dislodge the grunge as much as possible. If a flashlight will not show through the filter material it is probably in need of replacement.

[feltner58]

what about about the float sticking, is that something that would cause this?

[blaine]

what about about the float sticking, is that something that would cause this?
If the float was set to high,the bike would flood,plus you would see fuel comming out the over flow.
:) :cool:

[feltner58]

cleaned the throttle plate and float, still doing it, is the black plastic cylinder inside the carb the choke?

[blaine]

cleaned the throttle plate and float, still doing it, is the black plastic cylinder inside the carb the choke?
I'm not sure what part you are talking about,but it is not the choke.The choke (enricher) is the plunger on the end of the clutch cable that unscrews from the carb.If you download the manual,there is a exploded view of the carb with instructions for disassembly.This view is from BikeBandit,it may help.
http://s1.postimage.org/1zt7sa1xg/canvas.jpg (http://postimage.org/image/1zt7sa1xg/)

[jonathan180iq]

Just to clarify, when you give the bike some gas (throttle up) the revs stay high before finally coming down to normal?

If so, that sounds more like an air leak than a sticking throttle. If you've taken stuff apart this many times to clean them, its more likely that we're just overlooking an air leak somewhere.

From personal experience, something as simple as 4 little holes in the back of your muffler (for noise purposes...don't do it) can cause the idle to "hang" before dropping back down to normal.
Also, there is an "S" tube that runs from the top of the crank case into the bottom of the air box. It acts as a breather tube for crankcases cases. I accidentally slashed a gash in mine one time with my shoe and it wouldn't let the bike idle right.

You need to pull off the gas tank and go over every single rubber hose to make sure that they are not gouged or cracked or not properly connected at the ends. I'm really starting to feel that it's an air leak. And to find it, you'll have to check more than just one hose. Worst case scenario, you buy 6 feet of rubber hose and replace the 2 or 3 hoses just to be sure.
Remember, this bike is 10 years old.

[feltner58]

it doesnt go high then go back down it stays high until i turn it off

[Water Warrior 2]

While you are digging around you should check the air box drain tubing. It should have a plug in the bottom end and is only unplugged to drain moisture out of the air box.

[jonathan180iq]

What about the black rubber diaphragm under the carb top...
If someone has tried to rejet the bike and that black diaphragm was not centered properly, it would cause an eternal air leak that no amount of adjusting the idle or cables would ever solve.

When removed the carb for cleaning, did you remove the black plastic top?

[feltner58]

Yes I removed the black top

[jonathan180iq]

Did you verify that the rubber diaphragm was centered correctly and sealed? Even being a little bit off will mess everything up.

[feltner58]

Ill check it again, Its frustrating because it runs really smoothly but its just at a high idle like it runs at enough rpm to take off in first, I can ride it but its just not right

[jonathan180iq]

And even if you crank the idle adjuster all the way and loosen then tension on the throttle cable it stays high, right? ....

This is one of those that would be a lot easier if we could see it in person.

[blaine]

And even if you crank the idle adjuster all the way and loosen then tension on the throttle cable it stays high, right? ....

This is one of those that would be a lot easier if we could see it in person.
He had all the cables disconnected,as was suggested. :)

[feltner58]

yeah it stays high no matter what, I read something about a "hunting idle" which is cause purely by loss of air pressure, apparently it pretty common, does anyone have access to a blow up of the air hoses and vacuum hoses, so that I know where to look and can start checking all of them again.

[jonathan180iq]

It may be time for the poor man's air leak test.

Grab a can of something aerosol and flammable and spray it on hoses and other places where air could get into the intake system. At some point, I'll wager, you'll hear the idle change in one direction or another. The liquid will either plug the leak for a few seconds and the idle will drop down or the leak will be so bad that the liquid gets into the system and the idle will increase.

I used WD-40 to find an air leak on my Geo Metro and my 85 Saab 900S.
Good thing about WD-40 is that you can smear it around afterwards to make everything nice and shiny. :) and if that doesn't work, you can always spray it off.

Don't use anything with a solvent...like brake cleaner

[feltner58]

Ok so I took all the hoses off and checked for leaks with wd40 and theres none, so I reassembled it all and its still idling high, but on the right side of the bike (side where the exhaust is) there is what looks like a vent hose that I had checked for leaks and every time I put my thumb over the end of the hose it idled down its not a smooth idle but its not real high like it is when I don't block the hose, what could that mean? If the choke is disconnected could it still be stuck inside the carb because this all started the last time I used the choke when it was running and driving great.
??????????

[Water Warrior 2]

Ok so I took all the hoses off and checked for leaks with wd40 and theres none, so I reassembled it all and its still idling high, but on the right side of the bike (side where the exhaust is) there is what looks like a vent hose that I had checked for leaks and every time I put my thumb over the end of the hose it idled down its not a smooth idle but its not real high like it is when I don't block the hose, what could that mean? If the choke is disconnected could it still be stuck inside the carb because this all started the last time I used the choke when it was running and driving great.
??????????
You might just have found your problem. Trace the other end of the hose. I think you will find that it leads to the bottom of the air filter box. If it is indeed attached to the air box it is actually a drain tube that is normally plugged. You are just missing the plug. Plug it with a small bolt or screw which ever is handiest for you. You have just found your major vacuum leak. Then try to set your idle and other adjustments. Lottsa luck and good on you for noticing this.

[jonathan180iq]

A golf tee and a zip tie should work wonders :)

[feltner58]

Its not from the air box I checked that one its sealed with the stock plug and not leaking, this hose is coming from the carb (right side), is it possible for the carb to stay choked even if the choke is disconnected from the carb. when I do plug this hose it idles right but the throttle response is little or nothing, basically when the hose is plugged and I give it gas it bogs out or just has a really delayed response......any thoughts?

[geezer]

your chock is easy to remove and inspect takes a 14mm wrench and thats it. remove it from the carb and take a look, there is a spring in there that might be rusted up. i had to cut a bit off of mine to make it work again.

[geezer]

r u talking about your vacuum diaphram tube? it goes to the back of the petcock

[blaine]

Its not from the air box I checked that one its sealed with the stock plug and not leaking, this hose is coming from the carb (right side), is it possible for the carb to stay choked even if the choke is disconnected from the carb. when I do plug this hose it idles right but the throttle response is little or nothing, basically when the hose is plugged and I give it gas it bogs out or just has a really delayed response......any thoughts?
That is the air vent hose.It remains unplugged.When you plug it you get a delayed response,and bogging.If you have the choke disconnected it is not possible for the choke to be on.
:) :cool:

[blaine]

r u talking about your vacuum diaphram tube? it goes to the back of the petcock

Vacuum for petcock is on the left side. :) :cool:

[blaine]

your chock is easy to remove and inspect takes a 14mm wrench and thats it. remove it from the carb and take a look, there is a spring in there that might be rusted up. i had to cut a bit off of mine to make it work again.
He has the choke dissembled from the carb. :)

[feltner58]

spring for the choke is inside the carb?

[blaine]

spring for the choke is inside the carb?
The spring is on the end of the choke cable with the plunger.
:cool:

[feltner58]

there was no spring when i pulled it out

[blaine]

there was no spring when i pulled it out
Just so there's no confusion,the choke cable in the manual is referred to as the "starter plunger".The choke will still work without the spring.You will have less resistance at the choke lever.
:)

[5th_bike]

there was no spring when i pulled it out
It's item # 32 on the drawing of the carburetor, for instance see:
http://www.mrcycles.com/fiche_section_detail.asp?section=432067&category=Motorcycles&make=SUZUKI&year=2003&fveh=10117

[blaine]

there was no spring when i pulled it out
It's item # 32 on the drawing of the carburetor, for instance see:
http://www.mrcycles.com/fiche_section_detail.asp?section=432067&category=Motorcycles&make=SUZUKI&year=2003&fveh=10117
Items 31-35 are mounted on the choke cable. :)

[geezer]

you sure there are no exhast leaks? spray around the carb again try hitting the intake manifold from differednt angles. and hook your chock back up before you do this

[jonathan180iq]

Where do you live in SC? Someone needs to actually see this thing
...or just take it in to the shop.

[feltner58]

there's a ripple in the rubber diaphragm could that be causing air to escape causing the high idle?

[geezer]

did you ever instal that spring?