Just a few questions....

[GZ Jess]

Here is what I have noticed about my bike after riding a couple of weeks.

It will only start if the choke is closed (pushed all the way forward) and I turn the idle screw up. Ig I touch the choke at anytime it will either not start or stall out. After it runs for less than a minute I can back the idle down half and after the first couple of blocks I back it down more.

It tends to idle very high after a stop, especially a quick one, even after I have back it way down. I notice this even more if I have ridden a longer distance/time.

If I ride the bike hard or at speeds above 45 it will back fire every time I turn it off. Why does it do this?

I think that the back firing is more common with a carbed bike but I may be mistaken.

Do you think that my choke cable may need replaced? It seems that this is kind of common on these bikes (from what I've read).

Okay thank you, any and all opinions or advice is welcome!

[Easy Rider]

Originally Posted by GZ Jess

It will only start if the choke is closed (pushed all the way forward) and I turn the idle screw up.

Okay thank you, any and all opinions or advice is welcome!

How does it happen that you figured out that specific combination ??
If the "choke" is working right, it should also make the idle speed increase a bit.

NONE of that is "normal". Sounds like it is running VERY lean for some reason.
Continuing to ride it like that might harm the engine.

Is it all stock, as far as you know ??
Specifically, is there a stock air filter in place ??
A low restriction filter or an air leak around the rubber boots on either side of the carb can cause what you are describing.

A gummed up carb can cause it too. Have you run any carb cleaner through with the gas yet ??

Is this the first post you have made about how your bike runs ??
It is best to keep all of those kinds of questions together in ONE thread because they likely are all related. It looks like you are doing that; maybe it was someone else that has it spread out.

[mrlmd1]

The idle is supposed to be adjusted on a warm engine, not to start the bike. First set that right and leave it there. If it is idling very fast at a stop after it warms up, the idle is set too high. Or the choke (an enricher circuit) may be sticking in an engaged position (too rich a mixture). The idle and choke really have nothing to do with each other and if you start adjusting more than one thing at a time, you (and anyone on here) may never figure out what's going on.
And it's hard to follow you - what is back down, the choke or the idle screw when you stop and it idles fast? I just want to be clear.
The "choke" may need to be on a little to start the cold bike, that is, the lever pulled back towards the rider, slowly pushed forward as the bike warms up until it's completely off. I assume you are operating this correctly, or are you reversing the operation and pushing it all the way forward when you start it up?

Isn't backfiring (an explosion inside the muffler) caused by an overly rich mixture?

You would benefit from carb cleaner like ER suggested and also try and lubricate the choke cable and linkage if you think this is binding.

[GZ Jess]

Okay Easy, lets see, I had one other thread about the starting it when I first got it, since then I have notice the rest.

First off I could not get it started to save my sole. The guy had it started when my hubby went and looked at it and he turned it off and restarted fine. I tried using the choke like we do on the other bike bike but it didn't help at all. I found the screw under the seat, close to where my husband's choke is and messed with it. I noticed that it started to want to start so I moved it some more until it finally did. It has a very chug chug sound when it starts for a couple of seconds then revs very high. That is when I back off that screw. I tried giving it a little gas (and another time using the primer) before I started it as well but it just flooded.

When the bike is warm and running I have moved the choke to half to see what . It will at first rev slightly but then go back to normal idle speed.

It is an '04 and had 830 miles when I bought it. As far as I can tell it is completely stock, however I have not looked at the air filter, I had planned on doing a complete service on it but got to riding and forgot, I've only had it 3 weeks or so. The guy that sold it claimed to be a mechanic and said he serviced it at the beginning of the season but I don't know why you would do that and then sell it so I had intended to do it myself.

I have not run carb cleaner in it. Is seafoam a good one to get?

Thank you for your free advice I hate going to a shop and being taken advantage of. I like to have an idea of what I need before I take it.

[Easy Rider]

Originally Posted by mrlmd1

Isn't backfiring (an explosion inside the muffler) caused by an overly rich mixture?

Yes....no.....maybe. :biggrin:

A real "backfire" is through the carb and is something you almost never see these days.

So, the modern "backfire" that sounds like a gun shot, is indeed caused by raw gas getting into the exhaust somehow (too rich).

A little popping on decel, which many riders call a backfire but isn't, is most often the result of a too LEAN condition. I think that's what we have here.....maybe.

[Easy Rider]

Originally Posted by GZ Jess

I have not run carb cleaner in it. Is seafoam a good one to get?

Berrymans B12 Chemtool is better, I think.

And to echo what others have said:
You need to leave that idle adjustment knob ALONE when trying to start it. Opening the throttle just a tiny bit does exactly the same thing......but you should not do that when starting either, at least not until you hear it fire.

It sounds to me a lot like you have the operation of the choke backwards. Read the post just prior to this about which way is ON and which is OFF. This time of year, it should not need to be more than half ON.....but it's OK to have it full ON until it fires if you need to. After that, you should be able to listen to the engine and as it runs faster, reduce the choke just a bit.

The little beasts are cold blooded and it may take a full 5 minutes or warm up or riding before you can take the choke completely off.......and it the carb is dirty, it might take a LOT longer than that.

[GZ250]

do you know where is the air filter, open the left side cover and remove the air filter, smell it, if it has a lot of gas smell then your choke is kind of stuck and needs replacement, oiling sometime helps otherwise it is good to replace.

all starting and firing issues come under card or plug. did you check the plug. is it clean and new. if it is old replace it it is cheap and you will have a stronger spark. as Easy said use the additive and use a little more and do not completely fill the tank that way you can have fresh gas and new additive for faster cleaning.

when the bike is real hot after 30 mins ride (running) adjust the idle then to the minimum or slightly up and your high idle issue after stopping will go away. if idle is high i experience even a bad shifting in gears on my gz.

good luck

[Water Warrior 2]

When checking the air filter it has to be removed and visually inspected on the inside. The GZ design is kinda strange b/c the air travels from the inside to the outside of the air filter.

[GZ Jess]

Ok I will head to the garage to check the inside of the air filter, the plug and run some carb cleaner and report back after my 3 hr ride this afternoon!

Oh and it has never backfired through the carb as described, it is just a little poof when I turn it off. The hotter the bike the louder the poof.
I do have the choke operation correct it just does not seem to help to move it half or all the way open at all.

Thanks everyone!

[blaine]

Originally Posted by GZ Jess

I do have the choke operation correct it just does not seem to help to move it half or all the way open at all.

Suzuki's had a bad habit of the choke sieging up at the carb end.Dissemble with a 14mm wrench.Clean spring,plunger,and cavity.Check for proper movement of cable and reassemble.
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