More idling issues.....

[osborne]

Ive read through several of the idle issue and vacuum leak threads here and it sounds like my problem is a leak. My question is.......

Apart from the large {aprox 2.5"} hose connecting the air box to the carb at the rear of the carb......I can only locate two other air lines connecting to the carb.

1. is at the top rear of the carb {right side} and that one runs back to behind the airbox and just stops there....open ended.

2. the other is thinner and is attached to the upper right side of the carb.......just above where the throttle cables attach to the rotating, spring loaded bit. This one is about 4" long and has a slightly widened end which for the life of me I cant figure out where it goes. Is there a diagram anywhere or can someone explain where it goes? Thanks

[mainlinecoffee]

If I remimber correct there is a fuel overflow line to the airbox there is a vaccum line to the Petcock and possibly a breather to the slide in the carburetor. Can you post a pic?

[osborne]

in the morning Ill have a pic up

[TrevorG]

Yeah. Having just worked on this exact issue myself, the one on the top going out over the air box is just an overflow line, and the one in the back of the throttle with the widened end is a vacuum line that attaches to a nipple in the back of the petcock. If it is a leak, it will be from one of the rubber boots attaching the carb to either the airbox or the engine, or it will be from that line coming out the back going to the petcock.

I solved my problem by pulling the carb and giving it a good cleaning, then spending extra time making sure the carb was properly seated in the two rubber boots on either side and clamping those suckers down TIGHT.

[osborne]

Thanks.......Ive been through the carb 3 or 4 times now.....cleaned the jets and orifi pretty thoroughly. I changed out the OEM petcock for an ebay aftermarket unit. I don't believe there is a tit for that airline.

its here....mine is the bottom left unit.
http://www.ebay.com/itm/171284715565

Gonna try closing off the air line soon as the sun comes up and see if that helps.

One other question......the choke lever on the left switch housing....the spring tension has it all the way forward. That is, one has to pull it back towards the rider seemingly to engage it. Its so damned awkward Im wondering if its somehow reversed?

[blaine]

Yep.Back towards you engages the choke. ;) :)

[jonathan180iq]

Yep.Back towards you engages the choke. ;) :)

Meaning yours isn't messed up. This is how it should be.

[osborne]

Really? That's got to be the worst bit of engineering Ive ever seen on a bike. You have to pull the clutch in and pull it back at the same time. Anyone ever try turn it around so your thumb pushes it forward to choke it?

[TrevorG]

What? You don't have to do it at the same time. Pull the lever forward and it should stay there on its own. If it snaps back into place when you let it go then thats a different problem.

[osborne]

Let me explain. On mine, it rests at the fully forward position....relative to the bike. I have to pull it back against spring tension and letting it go it snaps forward again. Using one hand to pull the clutch in while also pulling the choke lever back towards me is strange. To my way of thinking its counter intuitive.

[TrevorG]

Yes, the choke lever should NOT snap back into place. When you pull it towards you to engage the choke, it should stay in place until you manually push it back.

[jonathan180iq]

The choke and the clutch are two completely independent things. You do not HAVE to pull in the clutch to engage the choke lever.

Secondly, and to reiterate, if your choke is snapping back into place on it's own, then it is messed up. It should hold whatever position you put it in. Time to pull it apart and fix it.

[osborne]

I understand and agree Jon.......the choke and clutch are two independent things. But........with the clutch safety lock out on these bikes te clutch lever must be pulled back to start the bike. My point was that operating the choke while also pulling in the clutch {at least in the current state on my bike} is difficult at best. The "current state" in this case being the choke lever snapping back to the forward position. I'll open it up and have a look but from the feel of it there must be a fairly strong spring somewhere in the choke mechanism causing this to return so forcefully.

[TrevorG]

I just had my choke mechanism pulled out last night. There is a spring in there. Maybe yours somehow got stretched out, causing it to return more forcefully? Maybe see if you can compress it. I checked my bike this morning before work looking for some sort of tension adjustment on the lever itself and couldn't find anything. It may be inside the actual housing for the hand grip control though.

[osborne]

thanks Trev.....I'll open it up in a bit and have a look.

[osborne]

ok.......Ive gone through the carb 6 times at least. New needle and seat....new O-rings......checked and cleaned all three jet screws thoroughly. She starts up and runs fine at a high idle for about 5 minutes, then the idle will fall off and she wants to stall. I can keep it running by throttling up for a bit but eventually she does stall and then wont start for several hours. I've checked gas flow to the carb and its fine. Seems that once it warms up it dies out. Been working this bug for a few weeks. New, high test gas btw. Any suggestions would be appreciated .

[raul10141964]

check the valves if they are to tried will stay open when the engine is hot

[osborne]

Sorry....."tried"? And how would I check them?

[osborne]

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Ive read in a few threads here about an air line leading to the back of the air box needing to be closed off. Ive attached 3 pics to this post. can someone tell me if this is the line needing closing off please?

[Water Warrior 2]

The air line that needs to be closed off is located near the bottom of the frame. It should have a factory plug in it and is only removed to drain mung and stuff from the bottom of the air box. If it is not plugged you will allow unfiltered air to be drawn up the tube directly to the carb and into the engine.
For those who don't know yet: the air box is a sealed unit and the airflow is reversed compared to most engine configurations. The air flow is from the inside of the filter to the outside of the filter into the air box and on to the carb/engine.
Cutting an opening in the air box for better flow is a big no-no. The air will then bypass the filter entirely and shorten engine life dramatically.

[jonathan180iq]

http://www.ronayers.com/CARBURETOR--C227891.aspx

I don't remember exactly where that line runs but it is not the air box drain tube. I don't remember if it's supposed to be capped or connected to something. It's not one of the breather hoses that creates vacuum for the gas tank... Cap it off and see what happens. And someone who still has the bike, check to see where yours leads.

[osborne]

In pic 1 that I uploaded, you can see the hose and its attachment to the carb...{upper left}. It runs from the carb along the top right side of the airbox and turns down dead ending near the bottom of the air box. If the hose in my pics isn't the mung cleanout for the airbox, what is it and where does it go?

[TrevorG]

If I remember correctly, that's just an overflow line to drain excess fuel from the carb.

[osborne]

You mean like when the carb floods.....to keep it from filling the crankcase? The line im holding in the pic ISN'T the bowl drain on the bottom of the carb. Just wanna be sure of what your telling me bro. Thanks.

[TrevorG]

Yes, in case it floods. There's the line at the bottom with a screw to drain the carb manually, but the one on the top is an overflow. I could be wrong, but that same hose is not attached to anything or plugged on my bike, just dangles under the air box, and the bike runs fine so I have to assume that it is just an overflow.

[osborne]

Thanks bro.......that's what I was wonderin. preciate the clarification.

[gz4me +]

TrevorG is right. The small line in the upper right, by trottle cables goes to petcock. Since you changed petcock, close that one off. The upper left is overflow. Then there is the bowl drain hose. I then have hose at front of carb. that goes down to a canister on frame. The only other hose is the gas line from petcock to carb. Hope this helps.

[osborne]

It did help. Nailed down each and every line and hose perfectly. Thanks to the members here.

[osborne]

The three screw in jets in the carb......they don't get O-rings, correct? Man, Im stumped. This bike warms up and the RPMs come down and it dies. For the life of me it acts like fuel starvation. I tore apart the gas cap to make sure it isn't a plugged vacuum equalization hole. Thing is, it takes hours before it'll start up again once it dies. Far longer than you'd expect either from an overheating issue or a fuel starvation issue.

All the answers and posts Ive seen here touching on this don't seem to account for that excessive time factor before it'll start back up. And when it does start, it fires right up on one touch.....no choke, no throttle.

[jonathan180iq]

So from bone cold, you can thumb it once and it will fire right up and run. It will idle and operate just fine until it gets warm, then it will idle down, die and refuse to start after that for this long period of time, right?

And when it does this, how long does it run during this "warm up" phase?

[osborne]

It idles high during the "warm up" phase. And it'll run for 8 or 10 minutes or so.....{I can have a smoke while Im waiting} longer if I throttle it up when it idles down and tries to stall. Throttling and Feathering it only gains me another minute or two of running time though. Then it stalls and wont start up for hours.

Hoping someone here sees and understands the symptoms I'm having and can put their finger on the culprit.

[raul10141964]

I see 3 possible causes
Valves are to tight resulting on lost compression on hat
CDI or coil fail on hat resulting on lost of spark
restriction on the fuel flow

[jonathan180iq]

I was leaning towards the valves too, but if they were too tight then the problem should be with starting, not so much once it's running. And he's saying that he can start the bike no problem with a single flick of the starter switch and he doesn't even have to use choke.

Did you ever fix your broken choke switch? That's another clue in this mystery. If it's flinging back into the closed position then it's never actually engaged. And I can think of maybe only 1 or 2 GZs that have ever come through this site that didn't need choke at start up. So that's part of the problem.

I also thought about the spark fail problem at temperature. This is not the same bike that had the CDI randomly fail, is it? While that's a possibility, you can easily rule that out by waiting for it to go into one of it's shut down modes and then testing for spark. Then you'd know.

When it refuses to start for several hours, it does turn over and at least try to start, right?

[raul10141964]

I work on Chinese scooters and I see similar symptoms when the valves are to tight
Watt happen is on cold the valves close but wend they expand on hat stay open lowering the compression

[osborne]

jonathan180iq;79468]I was leaning towards the valves too, but if they were too tight then the problem should be with starting, not so much once it's running.
That's kinda what I was thinking as well.

And he's saying that he can start the bike no problem with a single flick of the starter switch and he doesn't even have to use choke.
True, it fires up no choke, no throttle.

Did you ever fix your broken choke switch? That's another clue in this mystery. If it's flinging back into the closed position then it's never actually engaged.
I haven't bothered yet as it seems to work fine apart from a stiffer than usual return on the switch. The spring tension is toward the open choke position. While running, if I move it to or toward the closed position it chokes it out as one would expect.

And I can think of maybe only 1 or 2 GZs that have ever come through this site that didn't need choke at start up. So that's part of the problem.

I also thought about the spark fail problem at temperature. This is not the same bike that had the CDI randomly fail, is it?
No, it isn't.

While that's a possibility, you can easily rule that out by waiting for it to go into one of it's shut down modes and then testing for spark. Then you'd know.
Ill check that next. Assuming I find there's no spark while its in "shut down mode", what would that point to as a possible suspect?

When it refuses to start for several hours, it does turn over and at least try to start, right?
Yes, let it sit a few hours and it fires right up like nothing happened.

[jonathan180iq]

True, it fires up no choke, no throttle.
Did you ever fix your broken choke switch? That's another clue in this mystery. If it's flinging back into the closed position then it's never actually engaged.
I haven't bothered yet as it seems to work fine apart from a stiffer than usual return on the switch. The spring tension is toward the open choke position. While running, if I move it to or toward the closed position it chokes it out as one would expect.

Here you go: If the spring tension is keeping the choke in the OPEN choke position, then it's never turning the choke off. This would explain why your bike will start without problem and not need any choke - because it's always on - but it also explains why your bike starts running rough and will idle down and die once the bike is warmed up. Once warm, the stuck open choke is over enriching the circuit and keeping the bike from starting again.

I did this on accident one time and kept thinking I was running out of gas or that something terribly maleficent had embodied my bike and going to come next for my nuts. I then looked down, saw that my choke lever was left open because I'm basically an idiot, and closing it remedied the problem. (You also said it would idle high but stay running, which is another sign that the choke problem is the problem)




When it refuses to start for several hours, it does turn over and at least try to start, right?
Yes, let it sit a few hours and it fires right up like nothing happened.

What I mean to ask is that it's not like you have an electrical lockout. You can turn the bike over, it just won't crank, right?

[osborne]

sorry this took so long to get back. Here is my choke cable. In the 2nd pic you can see the choke plunger extended out because of the spring in the line. That corresponds to my choke switch being in the open {or default} position.

In the 1st pic you can see the plunger retracted, thus compressing the spring. This corresponds to me sliding the choke lever to the full "on" position. letting go of the lever allows the spring to decompress and pushes the choke lever back to the open {or off} position.

As I said earlier, this cable seems to be functioning properly. Is the spring supposed to be there, that is, is it a stock from the factory part? People keep telling me here that my choke lever shoudnt return to the open or "off" position by itself. Yet, that seems to be exactly what the spring is meant to do?


"What I mean to ask is that it's not like you have an electrical lockout. You can turn the bike over, it just won't crank, right?"
Correct......the starter cranks the motor but it wont fire up.


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[chromedome195]

I am no expert my any means....but my choke works like this. I push it to the choke position. It stays there. As the motor warms, I gradually push the choke lever back in reducing the amount of "choke". It does not turn off by itself. After about a minute I no longer need any choke. This is on a 1999 GZ250.
I believe your choke does not work as it was designed to work.
Again I am certainly no expert.....but just comparing it to how mine works, leads to my conclusion.

[osborne]

Howdy Chrome and thanks for the reply. Can you clarify something for me? when you are sitting on your bike, in what direction do you move the choke lever to operate it? On mine, {a 2000} the choke has a small decal painted on next to the lever itself indicating open/off is away from me and towards the front of the bike. That is the "at rest" position of the choke lever. Choke on is back toward me as I sit on the bike. Thus I have to pull the lever back towards myself against the spring's tension to choke the motor. Again......there is something counter-intuitive about this arrangement to my way of thinking. The attached pic shows the choke lever at rest. All the way forward,


Also, thinking a bit deeper about this......moving the choke lever back towards me into what appears to be the intended "on" position, The plunger on the carb end of the cable is compressing the spring and actually getting shorter. That is, its retracting out of the carb. Releasing the choke lever allows the plunger to get longer and push further inside the carb.

Sorry for being longwinded in my description. I just want to me clear about the problem Im having.

[chromedome195]

It is pouring here and my bike is covered---or I'd check to be sure.
But I think it moves towards me to use the choke and away from me to shut off the choke. If it ever stops raining here in the future---I'll be happy to verify that.

[blaine]

It is pouring here and my bike is covered---or I'd check to be sure.
But I think it moves towards me to use the choke and away from me to shut off the choke. If it ever stops raining here in the future---I'll be happy to verify that.
That is correct. ;) :)

[gz4me +]

I have a 2000 gz and pushing the choke knob away from me turns the choke off. Pulling the knob towards me turns it on. I do not have any spring tention snapping the knob back in either position. I do not have access to bike right now, so I can not check where the plunger goes into the carb. Something does not seem right, but I need to look at my plunger.

[blaine]

I have a 2000 gz and pushing the choke knob away from me turns the choke off. Pulling the knob towards me turns it on. I do not have any spring tention snapping the knob back in either position. I do not have access to bike right now, so I can not check where the plunger goes into the carb. Something does not seem right, but I need to look at my plunger.
As stated that is correct.Away from you:OFF Towards you:ON ;) :)

[osborne]

" I do not have any spring tention snapping the knob back in either position."

That, is what has me very confused. Several folks here have said the same thing. No spring tension returning the choke lever to the off position.

As shown in the pics I posted, there is what appears to be a factory spring in the line behind the plunger on mine, and mechanically speaking......it seems to work perfectly, returning the choke to the off position. But this means that I would have to manually hold the choke lever in the choke position while starting and warming it up. Wondering if I should try and remove the damn spring and see what it does.

[Water Warrior 2]

It might be helpful if some one else can varify having or not having a spring on their GZ. We don't have a GZ anymore so a present GZ rider will have to volunteer.

[osborne]

Agreed Warrior, maybe someone could grab a 9/16ths wrench and unscrew their choke cable from the carb and see if theres a spring justbehind the plunger. Thanks all. I looked on ebay for the part hoping to find if theres a spring there but wouldn't ya know it.....not one choke cable up for auction.

[TrevorG]

That spring is there on my choke cable. It's standard issue :P

What concerns me is that you said when you pull the lever towards you the on position the cable retracts and pulls the plunger out. I may be wrong, but if I remember correctly, mine operates the opposite. Pulling the lever to the on position actually pushes the plunger in, and pushing it back to the off position pulls the plunger back out.

[blaine]

That spring is there on my choke cable. It's standard issue :P

What concerns me is that you said when you pull the lever towards you the on position the cable retracts and pulls the plunger out. I may be wrong, but if I remember correctly, mine operates the opposite. Pulling the lever to the on position actually pushes the plunger in, and pushing it back to the off position pulls the plunger back out.
When you pull the lever towards you pulls the cable/plunger out of the
bore.The spring is there to help retract the plunger back into the bore when you Push the lever off. The friction of the lever in the casing is supposed to be enough to over power the pressure of the spring so the choke stays in place till you move it. ;) :)
http://www.ronayersmotorcycles.com/fiche_section_detail.asp?section=432067&category=Motorcycles&make=SUZUKI&year=2003&fveh=10117

#31 & 32 is Plunger & spring.

[osborne]

I suspected it might be working backwards. Someone must have been in it before me. Gonna try and finagle it and see if I cant reverse the action. Thanks everyone.

[raul10141964]

the picture show the parts you missing, I back up the screw so you see it better.
is located under the handle

[osborne]

OK.....the spring and parts shown in the last post are there on mine. But the more I look at my carb and choke cable, the more it seems like its working the opposite of what is should be. Pulling the choke lever back towards me...{giving it choke}....is retracting the plunger out of the carb. Applying choke should push it in, shouldn't it?

[blaine]

OK.....the spring and parts shown in the last post are there on mine. But the more I look at my carb and choke cable, the more it seems like its working the opposite of what is should be. Pulling the choke lever back towards me...{giving it choke}....is retracting the plunger out of the carb. Applying choke should push it in, shouldn't it?
Nope.It right.when you pull the lever you are pulling the cable witch pulls the plunger out of the bore & enrichen's the mixture so the bike can start cold. ;) :)

[osborne]

Well........as much as I hate to even consider this, Im thinking about putting it in a shop. I can usually fix a rainy day but this has me baffled. Both springs in the choke line are there and appear to be working correctly.....yet it returns to the off position by itself. starts up with no choke, no throttle and runs high Rs for about 6 or 7 miutes. Then it winds down and tries to stall. Feathering the throttle at that point will give me another few minutes but eventually it dies out. Then it wont start for hours.rebuilt the carb and had it off for close inspection at least 6 times now. New spark plug, new battery, new fuel, new petcock. Can anyone think of something I haven't tried yet?

[5th_bike]

Vacuum hose is OK? (It opens the petcock on "RUN" and "RES". )

Same behavior when you have the petcock on "PRI"? :hmm:

[Water Warrior 2]

Vacuum hose is OK? (It opens the petcock on "RUN" and "RES". )

Same behavior when you have the petcock on "PRI"? :hmm:
No. The prime position does not need vacuum to open the petcock for fuel flow. It is a direct flow from the tank through the petcock and to the carb. The prime position is mainly used to prime the carb after a long time of no riding and the fuel in the carb dries up. If you do need to prime the carb after a long sit in the garage be sure to put the petcock back in the run position after the bike starts.

[Fawlty]

WW. I think 5th was asking the OP if the symptoms are the same if the petcock is on 'prime' If not then the vacuum hose could be kinked, obstructed or not routed correctly. Maybe?

[Water Warrior 2]

WW. I think 5th was asking the OP if the symptoms are the same if the petcock is on 'prime' If not then the vacuum hose could be kinked, obstructed or not routed correctly. Maybe?

:lmao: That's what I get for multitasking. I have trouble reading, drinking coffee and typing.

[osborne]

My old petcock...{oem}....failed. I changed it out for a new, gravity feed unit that does not use the vacuum line. That line is now blocked off. I posted a link to the ebay auction for the new one back on page 1 or 2 of this thread.

[tnastvogel]

I'm new and I didn't read the entire thread, but I gathered that you took the carb apart a bunch of times and replaced a ton of other stuff. I'm curious if you took out the pilot screw? If you did, check to make sure that you installed the spring, washer and o-ring back in the correct sequence (o-ring should be at the bottom of the hole, then washer, then spring).

Also (again, not having read the entire thread), I'm curious if you checked the condition of the needle valve up close. Maybe just put a new one in to be on the safe side if that's something you haven't already done, and check the needle valve seat.

Maybe also check the long vacuum hose that runs down the intake side of the carb to see if it's clogged or something.

[Water Warrior 2]

Just reread this entire thread. A bit baffling to say the least. The one thought that keeps popping up in my head is.....is the choke really off. Is there is chance the choke is partial on inside the carb and unaffected by the choke cable? Maybe something is stuck and not allowing the guts of the carb to perform properly. This would account for the easy start and high RPM during warm up and an eventual shut down with the engine warmed up.
Bear in mind I have little to no carb experience but this seems worth investigating.

[tnastvogel]

If that's the case and the choke is somehow stuck on, check the new plug and see if it's fouled. If it is, then that's a possibility.

Try greasing the starter circuit.

[mainlinecoffee]

I just briefly flew over this thread but for what it's worth,I havnt used choke sence I rebuilt the carb. If it winds high and dies I would assume it was vac leak but not ruling out jetting float position or sticking. Mine still flutters and idles high when it gets hot.

[jonathan180iq]

It's his choke. Someone has fiddled with it before and it just needs to be repaired to factory operation.

[osborne]

I've attached two photos to this post of the choke mechanism full on and off. Could someone maybe get a measure of their own and post it? The pics show the measurement I need. And as an aside.......I've been through the choke from the carb to the switch and makes no sense to me that the switch returns so forcefully to the off position by itself. The spring on the carb end of the line doesn't appear to be distorted/stretched/tampered with or in any way problematic.

But I'm wo0ndering if cutting a few loops off the spring would ease the tension and stop the auto return on the switch?

[TrevorG]

A few weeks ago Raul posted a pic of a piece he said you may be missing. sounded pretty confident in his diagnosis. Did you ever check to make sure that part is there? It's a little rectangular metal plate with a screw sitting directly underneath the choke lever on the underside of the handlebar.

[osborne]

I did check and replied to raul. The small plate and the spring it holds in place are there on mine.

The bitch of this is that my local rice guy wanted $82.73 for a solenoid for this bike. {I got one on ebay for $10 bucks or so}.....so I'm almost afraid to think what he'd jam me to fix this choke problem. Prolly more than I paid for the bike!

[osborne]

OK........still working this damned choke bug. I replaced the choke cable with a new OEM cable this afternoon. While it did idle lower than before with some up and down in Rpms, it started with no choke applied and the spring return on the choke lever was as strong as ever. After 8 minutes or so it stalled out and wouldnt start. Emmediately pulled the plug and it wasn't "wet" but it was black and sooty. Zero smoke from the exhaust while it was running though.

2nd point.......I examined the small spring in the left hand grip housing. It would appear to be there to ride against the bottom of the choke lever {the internal "C" shaped end of the choke lever} and provide some tension countering the plunger spring's return. It doesn't seem to be making contact as in o0r out the return on the lever is the same. I even tried a small bearing on top of the spring, giving it extra reach to contact the choke lever. Still no effect on the return of the lever by itself to the off position.