Bear with me...

[GZ Jess]

I have a little mechanical knowledge but not much so bear with me while I try to explain my issues here.

I just bought a 2004 GZ250 with 830 miles. It appears to be well taken care of.

I understand that when you start a cold bike you need to pull out the choke. This bike has issues starting. The starter sounds strong and battery appears strong. Some times it will turn over a couple of times and stall out and others times it won't start at all. Once I do get it running for a few minutes and turn it off, it will start right back up no issues.

I did find a screw that seems to adjust the idle and that is how I get it started. When I get it started and running if I move the choke lever it stalls out whether it has been running or not. I thought originally that if I could get the bike warmed up enough I could put the idle screw where it needed to be to run smooth warm and then be able to just open the choke to start then close as it warms. But if the choke is moved it doesn't up the RPMs like I think it's suppose to and it just stalls the bike out!

I'm stumped now. Any ideas?

Thanks, Jess

[alantf]

I suppose you DO know that the GZ is supposed to idle at 1200 - 1400 rev/min? The "screw" you "found" (if it's the one with the big white knob) is not meant to be used as a starting aid, but used to set the idle when the engine is HOT.

Right - get the engine running by whatever means you can, then let it get really HOT (go for a ¼ hour ride, not just let it get hot while it stands)
Get the choke off as soon as you can, & if it stalls, screw up the white knob a little, until it's running. When it's nice & hot (& ONLY when it's nice & hot!) adjust the white knob until the bike sounds as though it's doing 1200 to 1400 revs. This is your starting point. On subsequent days, when the bike is HOT, you can tweak the knob SLIGHTLY until you get it running to your liking.

A lot of idle problems seem to be caused because people think that a bike idle should be as slow as a car. :) :2tup:

[GZ250]

good reply and i agree with alantf. starting even during summer mornings you will need choke. either half or full choke start the bike and decrease as needed. for GZ the battery should always be strong to get a good crank otherwise in 4-5 tries the battery drains so keep a battery tender handy.

as suggested earlier adjust idle when the bike is real HOT. i cannot measure the revs as i do not have any tool for that but i personally keep it to minimum as it gives me more smooth ride and gear shifting (its just personal).

i can't say for other bikes but if GZ is cold it will stall and ride is not smooth. only when the engine is real warm it runs great.

[Easy Rider]

Once I do get it running for a few minutes and turn it off, it will start right back up no issues.

But if the choke is moved it doesn't up the RPMs like I think it's suppose to and it just stalls the bike out!


Welcome; hope we can help you out.
It sounds like several things might be going on here.

The choke is NOT an all or nothing device and needs to be changed a little at a time; not all on or all off. My GZ started best with about 3/4 choke; do NOT open the throttle until after it starts, that messes up the choke action. Then when it does start, you need to keep the choke partly ON for a while until it warms up.

Having said all that, if slowly moving the choke while it's running does NOT increase the engine speed any and eventually makes it die, then your choke linkage may not be working right.

AND regardless of what else might be wrong, you need fresh gas and some good carb cleaner for a tank full or two. I like Berrymans B12 Chemtool. If you drain the gas, drain the float bowl too.

While we would LOVE to help you find a solution to your problem, sometimes there is a "failure to communicate" and it might be best to visit a dealer or find another experienced rider to show the problem to. There should be some good clues available even when the bike is hot and running good.

Have you checked the air filter yet ??

[GZ Jess]

Thank you everyone, I have not checked the air filter which I should do ASAP (thank you for the reminder) and carb cleaner is another excellent idea! However, I do think that there may be an issue with the choke linkage, as was suggested, because it doesn't seem to do what other bikes do when the choke is adjusted. Even when the bike is hot and running nice and smooth, if you adjust the choke just to see what will happen it stalls the bike out.

Thank you all very much, I am glad I found you all!

[blaine]

Thank you everyone, I have not checked the air filter which I should do ASAP (thank you for the reminder) and carb cleaner is another excellent idea! However, I do think that there may be an issue with the choke linkage, as was suggested, because it doesn't seem to do what other bikes do when the choke is adjusted. Even when the bike is hot and running nice and smooth, if you adjust the choke just to see what will happen it stalls the bike out.

Thank you all very much, I am glad I found you all!


Hi,Welcome.If choke stalls the bike when it warm than it is working.

[Water Warrior 2]

About the air filter. Be sure to look at the inside of the filter. It is opposite air flow to what is the norm so crap collects inside and not on the expected outside surface.

[Easy Rider]

If choke stalls the bike when it warm than it is working.

Not necessarily.

Most bike's I've had will increase the idle speed enough that it keeps running even with the "choke" completely operated. This is with modern engines with an "enricher" instead of a "real" choke.

If it doesn't increase the idle speed at all and then it dies before the choke is fully operated, then something is definitely wrong, probably with the fast idle cam.

[Water Warrior 2]

If choke stalls the bike when it warm than it is working.

Not necessarily.

Most bike's I've had will increase the idle speed enough that it keeps running even with the "choke" completely operated. This is with modern engines with an "enricher" instead of a "real" choke.

If it doesn't increase the idle speed at all and then it dies before the choke is fully operated, then something is definitely wrong, probably with the fast idle cam.
Whoa Easy. That may be true in general and almost a rule of thumb but Lynda's bike ran it's own rules and we never had a problem with it. After partially warming up a little more choke to increase the idle would KILL it dead with a terrible mechanical last gasp. The fast idle worked and only the actual idle was ever adjusted after we got it. Maybe that is what Suzuki intended.

[blaine]

If choke stalls the bike when it warm than it is working.

Not necessarily.

Most bike's I've had will increase the idle speed enough that it keeps running even with the "choke" completely operated. This is with modern engines with an "enricher" instead of a "real" choke.

If it doesn't increase the idle speed at all and then it dies before the choke is fully operated, then something is definitely wrong, probably with the fast idle cam.

There is no fast idle cam on the G.Z.The "enricher" when closed richens the mixture by letting in more fuel,therefore speeding up idle.When my bike was stock it would act as you stated because of lean condition.When I done all three carb mods it takes much less choke to start the bike when cold.When warm the "enricher" will increase idle,and stall bike out because of richer mixture.

[GZ Jess]

I am so trying to follow all of this LOL! Just about everyone I talk to has a different idea of what, when and how to use the choke! And it is probably different on every bike.

[Easy Rider]

I am so trying to follow all of this LOL! Just about everyone I talk to has a different idea of what, when and how to use the choke! And it is probably different on every bike.

Sorry. We tend to get side-tracked sometimes. :roll:

A choke always works the same way; it is NOT different on every bike.
You need SOME choke to start the engine when it is COLD.
You need progressively LESS choke as the bike warms up.....until eventually it is completely off.

That assumes a stock bike that does not have a major malfunction......like a clogged air filter, for instance, or bad fuel or a dirty carb. :biggrin:

[Easy Rider]

After partially warming up a little more choke to increase the idle would KILL it dead with a terrible mechanical last gasp.

You said "more" and I think he meant "any"......at least that's what I understood.

IIRC, my GZ would take a good bit of choke when hot and would speed up a bit until about half choke where it started to stumble a bit. Don't think I ever took it farther than that. I don't doubt that full choke or too much would make it die.

I still think that applying just a LITTLE choke (enricher) should NOT cause the bike to die.....unless maybe it is running too rich already......in which case you might not need the choke in the first place. It can be tricky.

[Easy Rider]

There is no fast idle cam on the G.Z.

Nothing inside the carb to accomplish that function either ??

If you leave the choke on too long, the idle speed will go up quite a bit.
I just can't see that happening without letting in a little more AIR too.
It should not speed up much on gas alone.

[blaine]

There is no fast idle cam on the G.Z.

Nothing inside the carb to accomplish that function either ??

If you leave the choke on too long, the idle speed will go up quite a bit.
I just can't see that happening without letting in a little more AIR too.
It should not speed up much on gas alone.

That is true when bike is cold,will stall out when bike is warm due to more fuel than air.On older vehicles the choke accomplishess same thing by reducing the flow of air to enrichen mixture,therefore the need for a fast idle cam.Fuel enrichment system has less moving parts.

[alantf]

when and how to use the choke! And it is probably different on every bike.

It sure is. My European model is set up richer than the American version, from the factory.(due to less stringent emission regs). This means that it is slightly faster, & the only time I need to use the choke when starting is when it's been standing for 2 or 3 weeks when I've been on holiday. :)

[dannylightning]

yeah you want the choke to be pushed in completely when the bike is warmed up. it will stall out if you pull it out after warm up.

that bike is made to idle fast, when i first got mine i put it down to a low idle and found out that is bad for the engine. so look up some gz videos on youtube
and try to judge your idle speed by those, that is what i did.

[GZ Jess]

I'm back....

I have put around 600-700 miles on my bike since I used the Berrymans. Right after the tank of cleaner I checked the plug and it was loose so I tightened it. The bike seemed to be running fine until recently.

Symptoms:
*Hard to start but can be started and kept running with the throttle just slightly twisted until warm
*Choke placement on, 1/2 or off does not make a difference in starting
*Choke turned on (out of curiosity) when egine is warm causes a momentary fast idle then back to normal
*When bike isn't ridden for a couple of days and I get it up to highway speed there is a hot smell for a minute then it is gone
*Started to have a popping or flapping noise from the exhaust when I let off the throttle
*Air Filter and box smell of gas

What I have done:
I got a new plug and used a gapper before installing it
Drained black air box hose (almost 2 ounces of dark gas smelling liquid came out)
Filled tank with more Berrymans

I want to empty the float bowl but haven't found a thread that showed or explained well enough for me to try. (I have never messed with a carb and am a bit scared to do the wrong thing) Any other suggestions or input would be great. Thank you.


Sorry I just noticed that I did not post this on my long thread before like I had intended.

[Easy Rider]

I want to empty the float bowl but haven't found a thread that showed or explained well enough for me to try.

Go here:
viewtopic.php?p=3814#p3814 (http://www.gz250bike.com/forum/viewtopic.php?p=3814#p3814)

Scroll down to the pictures labeled: "Empty the float bowl".
One shows the drain screw with the drain hose OFF and the next one shows it from the other side with the drain hose ON.
Put a can below the end of the drain hose and loosen the screw until gas comes out of the hose; a couple of ounces at most. Leave it open and switch the petcock to "PRIme" for a few seconds to drain some more through the bowl. Tighten the screw; don't over-do it. Switch to PRIme again for a minute or so to re-fill the bowl.

How much B12 did you put in this time ?? You may need to double up.

It sounds a lot like you might have a vacume leak though. If it doesn't perk up after about a half tank we can check that out. Your air filter IS still firmly in place, right ??

[GZ Jess]

Thank you Easy! I did just as your wonderful instructions stated and I drained the bowl. The gas that came out was clean. I don't know why I was so afraid of that!

So I put everything back together and she fired right up with proper use of the choke! This is the first time the choke has done what it is suppose to do for me! I still had some popping when I let off the throttle but last time I used the Berrymans that stopped. Last time I did the recommended ounce per gallon or rather I put 4 oz in a full tank. This time I had just and ounce left after the 4oz so I dumped it in for a total of 5 oz on this full tank.

You must be a mind reader, my air filter is back in but I noticed that I am missing one of the 4 mounting screws. Could that be a problem?

I will let you know after I get through some of this tank of gas.

[Easy Rider]

You must be a mind reader, my air filter is back in but I noticed that I am missing one of the 4 mounting screws. Could that be a problem?

Not likely. Any Jap dealer or hardware store could match it close enough for a replacement.

Just as a review: THE BIKE WILL NOT RUN RIGHT WITH THE AIR FILTER OUT !!!

That clear stuff that came out of the carb might not all be gas.

Keep us posted.

[GZ Jess]

I didn't try to run the bike with filter out. I didn't think that was smart but maybe I am wrong.

The clear liquid smelled like gas and was clear but I don't know how to tell if it was something else too.

Thanks, Jessica

[Sarris]

Just another suggestion. Take it out and run the crap out of it. Mine runs bad after it sits and seems to benefit from a good hard run.

After it warms up, I find a 55 mph road and run it hard to the red line in all gears a few times and it seems to blow the crud out of it and it immediately runs better.

Just my 2 cents worth. :)

[alanmcorcoran]

Just another suggestion. Take it out and run the crap out of it. Mine runs bad after it sits and seems to benefit from a good hard run.

After it warms up, I find a 55 mph road and run it hard to the red line in all gears a few times and it seems to blow the crud out of it and it immediately runs better.

Just my 2 cents worth. :)

:plus1:

[GZ Jess]

After draining the air box hose, draining the float bowl, putting a new plug in, putting 5 oz Berrymans in a full tank and changing the oil I ran the bike for about 30 miles last night, half of it pretty hard. It runs so much better. There is no popping/flapping on deceleration and it seems to start easier with the use of the choke. I think that I will just monitor the gas smell and liquid in the air box hose and see how it goes. Thanks everyone. Jessica