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Suzuki bandit stalling a few minutes after start! (merged)

27K views 31 replies 6 participants last post by  Tico Rico 
#1 ·
Suzuki Bandit running problem, can someone help?

Im having a problem with my bike so ill list all the infor
2001 Suzuki Bandit 600
4 cylinder, 4 carburator
Just changed the spark plugs

I was going to ride to work and after about a mile of riding i noticed my RPMs were falling. At a stoplight it seemed like the bike was going to stall, I had to hold the revs up to keep it from stalling. I pulled over to the side to play with it and when i let go of the gas the bike stalled. I tried restarting, no luck. I tried playing with stuff, no luck. I ended up waiting about 5-10 minutes calling insurance to get it towed. I tried starting up my bike and it ran fine! I drove a little less than a mile and started having the problem again, so i puleld over and same problem. I decided to drive it home, and waited 10 minutes and it started again. Sure enough the problem came back so i just held the throttle so it wouldnt die till I got home. Even then soemtimes it wasnt responsive to gas while accelerating from a slow speed.
I jsut had the bike for a regular service, so i would expect them to have found something obvious wrong.

I had had problems before i got it serviced that i think stemmed from having the bike sit for 2 months while not being driven. The people at the service station didnt report anything.
There is enough oil.
The battery turns over just fine, doesnt seem electrical.

Ill list the other things ive tried
Tried running it with the gas cap open to see if there was a vacume problem, but it didnt help.
Added seafoam to the gas, no help.
The petcock didnt seem dirty at all
I did a number of things today.
I checked the air filter, clean
Then i pulled out the carburetors and i opened up the top and bottom, checking the float, the little plunger attached to the float, that long needle that is attached to the diaphram on the top. I didnt pull out all the screws, i just puleld out the mainjet and inspected them. Clean. The other recessed small one i didnt have a screwdriver that would fit. Well one was too skiny and wouldnt turn the screw well.
The insides all appeared clean, couldnt find any gunk/residue/slime/anything. I put it all back together put the tank back on, started it up and let it run. The motor sounded slightly different. Maybe a little bit rougher but nothing bad. Sure enough the problem surfaced after a few minutes of being on.
I checked the spark plugs, slightly black but im guessing thats normal?

Important thing i found. As i was reading through my manual for any other ideas i saw a picture of a hose I had always wondered about. The picture said it was a drain hose and you remove the plug to let any water drain out. This hose comes from the air box. The section was talking about air filter cleaning. So i figured what the heck, ill go open it.
So i find it and open it and this liquid comes out pretty fast. I plug it back up and get a cup to catch it. I let it drain and i would say all in all abou 3/4 of a cup of this liquid came out. It is amber in color, smells a little bit like fuel but not completely, is to viscious to be oil or transmission fluid. Dirty liquid i think, had a small amount of sand like stuff inside too. Maybe a mixture of water and gasoline? It doesnt seem to evaporate real fast either, there is still some residue on the ground. I clean some of it off the ground with a paper towel, then to figure out what the liquid is i folded up the paper towel and lit it on fire. It caught fire taking about 5-10 seconds before the fire spread to the whole paper towel. It gave off a black smoke, and i had to stamp it out.
Gasoline would burn faster wouldn it?

So not sure what the fluid is but im hoping that was somehow the cause of my problems. Ill go start the bike and see what i can find...


EDIT:
I turned the bike on and let it run. After a few minutes the problem resurfaced. Surely that liquid isnt supposed to be there but i thought draining it would have solved my problem... darn...

Help is much appreciated.
 
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#2 ·
I was going to ride to work and after about a mile of riding i noticed my RPMs were falling. At a stoplight it seemed like the bike was going to stall, I had to hold the revs up to keep it from stalling.
I see only 2 probable causes:

Something in the ignition is heat sensitive
OR
Your are effectively running out of gas.

Since you can reproduce the problem in the garage, get a can of starting fluid (ether). When it starts to stumble, spray a very short squirt into the air box. If it picks up (runs better for a few seconds) you know your problem is fuel. My guess is that fuel IS the problem.

This test is not fool proof, however, since the problem could be getting too much fuel in one (or more) cylinder. If that is the case, I think the ether would have little effect, just like it would if there was an ignition problem.

One thing at a time!
 
#3 ·
Ok, sounds like a good way. Starting fluid? is that different from gas?
And where do i spray it into the air box?

Heat seams like a possible problem. Im guessing the 5-10 minute cool down lets whatever defective part cool down enough. Maybe water is condensing as it cools back down and it can run again?
 
#5 ·
I had got it running and drove it around a few times a week for at least a month before i took it in for service. The floats didnt seem at all stiky when i took apart the carbs and checked them out.

Serious carb work i would have to leave to the professionals. Thanks though.
 
#6 · (Edited)
This sounds like oil mixed with water and debris from your air filter. It definatley should not be in there and I would take it back to the dealer you got it serviced at and inform them of the stalling and the liquid from the air filter housing drain. There are several reasons why oil gets into a filter one being badly worn bores/rings/pistons. This depends upon how much mileage and attention your bike has. You may have had the oil overfilled also and this would cause a similar thing. Post back and tell us more re the stalling...does smoke come from the exhaust.... has the bike been dropped...what was done on the service etc.... You mention the plugs being slightly black...how black...this could indicate a rich mix...check your choke cable...I am assuming the set up for the 600 is the same as my 1200...the choke may be jammed on. Another point is the vacuume pipe for the fuel feed...make sure its not crimped under the tank. The final point is to take it for a run at high throttle and kill the engine then pull the plugs dark fluffy deposits = rich white powdery = lean and slimey black = worn bores/pistons/rings (possibly)...easy to say but a little harder to accomplish as the tank has to come off. This is called a plug chop and is the only reliable way to tell your fuel mix status.

Good luck

Steve

Some other points I forgot to ask. Where do you park your bike, does it get wet, and did it rain heavily at all during the 2 month storage. Another point is if it sat for two months did you run it at all. I understand your fuel has alcohol added and this can play havoc with fuel systems. Also check very carefully all lines and filter bowels etc for water in the fuel, also your tank.... worthwhile draining it and refilling with fresh gas I reckon. One final thing is seafoam in the gas may just clear a tiny blockage that might be a problem. I have never use the stuff but others on the forum swear by it.
 
#8 ·
Im pretty sure the drain hose isnt plugged, i even ran the motor with the tank cover open.
I park it under a garage.
I did not run it for that 1.5 - 2 month period, but had put a few hundred miles on the bike since that happened and it was serviced.
The service was a general service where they tighten all the bolts and check everything. About $350
The spark plugs were slightly blackened, a thin layer that rubbed off with a peper towel.
Yes hawaii fuel does have ethanol, but i only buy premium.

The liquid that drained out of the air box wasnt oil, it was rather thin and didnt feel like oil, and i would be able to tell if it was mixed with water because of the way water and oil mix... or dont.
Pistons, i would have to take it to the service station.

The oil is above the full line but the service station did this and it ran for about 200 miles after it was surviced with no problems, except maybe for vapor lock. Sometimes when i try to start the bike the engine turns a little bit then gets stuck, i have to roll the bike and let out the clutch to losen the engine.
Bike has been dropped but never hard. It was at like 1 mph and i was able to slow the drop so there wasnt really any damage, and that was a long time ago.
Choke seems fine, ive been able to use it.

Havent tried fresh gas, though the gas in there cant be older than a few weeks. Well at least a few weeks since the problem first came up.
 
#11 ·
Yes.......in Hawaii, maybe.

It is generally used to help vehicles start in VERY COLD weather and, of course, you don't know what that really is! :mrgreen:

If you don't see it on the shelf, ask. I'm sure there isn't much demand in your neck of the woods.
 
#10 · (Edited)
I don't like the sound of the engine seeming to get stuck and rolling the bike to loosen it. This sounds like mechanical damage. From the sound of your primary problem you may be starved of oil. The engine runs first up then begins to loose power and finaly stalls. Does it get very hot?

I would definatly take it somewhere and get a proffessional opinion before going any further. Is the oil filter correctly fitted? Check oil is actually being pumped round the engine. I cannot think it is this but from the sound of the motor getting stuck it has to be something serious.

This model is not water cooled is it. If this is the case perhaps the head gasket is blown and coolant is getting into the oil. Check the oil for contamination ditto the coolant. I can't think of many other things it could be and without seeing the bike eyes on so to speak its difficult to give an accurate diagnosis. If it were mine I would take it to a Suzuki dealer and let them fool with it. You say you took it to a service station for the regular service correct???

Post back and let us know how you go.

BTW I wasn't refering to the drain hose being plugged I mentioned the vacuum pipe for the fuel cut off valve.... its under the tank on the fuel valve itself and crimping this starves the engine of fuel due to little or no vaccum to the fuel supply.

Good luck

Steve

Edit: How long do you have to crank the engine to get it to start? When you say the engine gets stuck are you sure its the engine and not the starter motor? How stuck is stuck? does it take a lot of effort to get the motor to turn using the gears? What mileage have you got on it?
 
#12 ·
After 5-10 minutes of being on it gets hot, though im not sure if its abnormally hot.
The engine getting stuck, could it be vapor lock?
The engine is not water cooled.
I heard that if you run it with the gas cap open and it runs fine then there is a vacume problem, but i tried that and it didnt help.
the bike ahs 40,000 miles
Ill press the starter, which i think is ok, and it will turn a little for a fraction of a sec and stop. If i repeat, same thing. I will have to roll the bike a foot or two and let the clutch out, then ill press the starter and it will turn a little bit, but i little bit more than before. Repeat this process a few times and then it will turn over freely. Then its jsut a matter of holding it down until the engine starts, which sometimes isnt long and sometimes is a few seconds and a little throttle play.

I hope that info heps.
I could add more seafoam, but its bad to add to much right?
 
#14 ·
Ill press the starter, which i think is ok, and it will turn a little for a fraction of a sec and stop. If i repeat, same thing. I will have to roll the bike a foot or two and let the clutch out, then ill press the starter and it will turn a little bit, but i little bit more than before. Repeat this process a few times and then it will turn over freely.

I could add more seafoam, but its bad to add to much right?
Ah, ha. Maybe there is another possibliliy. Maybe the battery is about to shoot craps. I STRONGLY suggest you get your battery and charging system checked before you do anything else. Not likely it is causing ALL the problems but there is an outside chance.

As for the Seafoam, it is (generally) not strong enough to clean a REALLY dirty carb. After the battery test (and maybe a new one), you should DRAIN THE GAS and put in fresh. If that doesn't help, then we can talk about "real" carb cleaners.
 
#13 ·
Ok the starter motor seems to be the problem there, phew! (lucky you) To get back to the original problem your motor must be starving fuel this is the only thing that could cause the motor to die in the way you are explaining it. If it were electrical you would generally get some bad firing...misfires etc... and I would expect the bike to be hard to start. I suggest you pull the carbs and set everything up as per the manual then work back from there. As for the crud in the filter box there may be a problem with the oil breather valve or it may simply be because the service dude overfilled it. I do not suspect it is the cause of the problem however it may also be something to do with the carbs...after all they are fastened to it!

Keep us up to date and (hopefully) with help from the forum you will be able to fix whatever it is.

Good luck

Steve
 
#16 ·
Im pretty sure the starter motor is fine. The stuck motor doesnt see to be electrical though because once i get the motor running, it will turn over just fine try after try, and that problem wont resurface till the bike has been sitting a few days.

I bought some starter fluid, ill try that out today. The guy at napa said blackened spark plugs could either be fuel problem, or wrong spark plugs or needing new wires. Wires havent been changed since new as far as i know. The battery behaves like a good battery should. It doesnt have that many miles on it. In fact even when the bike had sat for a few montths with no riding, the battery didnt behave like it was weak or anything.

As far as the oil, i guess i could let a little bit out till the level returns to normal.
 
#17 ·
Im pretty sure the starter motor is fine. The stuck motor doesnt see to be electrical though because once i get the motor running, it will turn over just fine try after try, and that problem wont resurface till the bike has been sitting a few days.
What we are trying to tell you here is that the motor might NOT be sticking at all. It might not be getting enough voltage to do the job.

There are several possible causes for this:

WORN OR DIRTY BRUSHES is the most common cause of starter failure on old jap bikes. Whether or not it works at any given time depends on exactly where the comutator stops in relation to the brushes. There may be only 1 bad spot.

Loose or corroded main battery cables. Check both ends. This can be an intermittant problem too.

Intermittant battery failure. Not likely since it is new but not impossible.
 
#18 ·
Update.
Checked the spark plugs again at the advice of a NAPA dude. He said sometimes they might put in the wrong spark plug, there is standard, cold and hot. He said older bikes might need hot, so i checked the manual.
Standard: CR9EK Cold:CR10EK Hot: CR8EK
I pulled out a spark plug and it was labeled CR10EK. Hawaii doesnt usually get cold. Also the plug head was indead black and when i wiped it with a paper towel black stuff (carbon?) would wipe off, kind of powdery. It had a slight smell, possibly fuel.

I checked the drain hose comming from the air box again and to my surprise, it dumped out another cup or so of liquid. Will fuel mix with oil to make an amber colored liquid that is thin like fuel but leaves a residue like oil? There are only 2 tubes that run into the air box, one comes from a device that splits into 4 tubes that connect to the engine just below the ehaust pipes. Im guessing this provides suction or pressure? The other tube comes from a block like shape that is part of the head of the motor. Is this an oil overflow or something?

I pulled off the tank and had it running, I sprayed some starter fluid into the intake when it was starting to run a little low on the RPMs, didnt seem to change anything. So i pulled off the filter and tried to start the bike but couldnt get it to stay running and spray it in the box at the same time. So i sprayed a half second spray into the air box then tried to start it but it didnt seem to change anything. Maybe im doing something wrong here or is this pretty simple?

One other thing I did do was i decided to drain some oil. I set it up to drain slowly until i saw the line come down. Well i filled about 2 cups worth of oil, and dropped the plug and spilled a bit more oil DOH! I plugged it back up and got the bike to run. It ran for a few minutes and the problem surfaced and the engine died. The bike straight upright on the rear stand. I looked at the window and it was still above the full window. When i put the bike on its kickstand i noticed the fuel was just about the F line. I guess this could be two things, either the oil isnt circulating or there was way too much. I watched the window as it was running and saw the oil churning and whatnot so the oil seems to be moving about, so im guessing the oil is circulating.
The engine didnt seem unusally warm after the time it was running.
I checked the air box drain hose one more time and found that it hadnt filled up while working on it/running it.

I havent checked the battery, but i dont have toold to check electrical stuff.

Im starting to wonder if the shop messed something up on the bike. I know they put the flanges that connect the exhaust to the engine on backward.
Thanks for all the ehlp and patience so far.
 
#20 ·
Update.
Checked the spark plugs again at the advice of a NAPA dude. He said sometimes they might put in the wrong spark plug, there is standard, cold and hot. He said older bikes might need hot, so i checked the manual.
Standard: CR9EK Cold:CR10EK Hot: CR8EK

I pulled out a spark plug and it was labeled CR10EK. Hawaii doesnt usually get cold. Also the plug head was indead black and when i wiped it with a paper towel black stuff (carbon?) would wipe off, kind of powdery. It had a slight smell, possibly fuel.

I checked the drain hose comming from the air box again and to my surprise, it dumped out another cup or so of liquid.

I pulled off the tank and had it running, I sprayed some starter fluid into the intake when it was starting to run a little low on the RPMs, didnt seem to change anything.

One other thing I did do was i decided to drain some oil. I set it up to drain slowly until i saw the line come down. Well i filled about 2 cups worth of oil,
I think we have enough information now to make a confident diagnosis! :mrgreen:

While you probably should go back to "Std." plugs, that's not the source of the problem.

ALL of the symptoms you relate points to the bike running VERY rich, to the point of flooding out. Black soot on plugs, gunk in air box AND over-filled crankcase (because GAS is getting in there!!!!) and the fact that ether doesn't help when it stumbles (because it has too much fuel already).

So, it's back to the carbs and more specifically the floats and the needle valves. Either: one (or more) of the floats is not "floating" any more OR the adjustment is way off OR the needle valve is not closing off the flow of fuel like it should.

This could be combined with a petcock that is not shutting off the fuel when the engine is off. If you have a manual OFF position, you are using that when parked, right ???

CAUTION: Do NOT run the bike more than a few seconds until you change the oil. The old oil is contaminated with fuel and is not lubricating as it should. You might then have to change it AGAIN after you get the problem solved.

And last but not least, you might be able to identify which carb(s) are in trouble by looking at ALL the plugs. Hopefully only one will be black and sooty or one will be a LOT worse than the others.
 
#19 ·
I'll go look at the hoses you mentioned a little later and try to help you there. For now, lower the engine oil level to the full line with the bike on the centerstand. Sounds like it is overfilled.
 
#21 ·
I think all the plugs were similarly black, but ill have to check that again.

How would the fuel get into the oil? I guess if fuel got into the oil that would make the oil level too high. And the fuel would thin out the oil right?

The little plungers attached to the floats seemed alright, but those cant cost that much i might as well replace them. I read the manual but I am still a littl confused on how to check/adjust float height. Ill go read it again. Are the needles adjustable or would I jsut need to replace them. I didnt see any damge to the needles themselves or the plunger rubber.

The petcock does not have an off setting, its a vacume system.
 
#22 · (Edited)
How would the fuel get into the oil? I guess if fuel got into the oil that would make the oil level too high. And the fuel would thin out the oil right?

I read the manual but I am still a littl confused on how to check/adjust float height. Ill go read it again.

The petcock does not have an off setting, its a vacume system.
Fuel gets into the oil by: Carb overflows and raw gas is sucked into piston. It runs past rings into crankcase. Yes, it thins the oil !!!

Float adjustment is often done by bending a tab on the float mounting arm and the measurement is usually made with the carb OFF the engine and upside down.

OK, here's one more idea for locating which carb is causing the problem.
Do the carbs have overflow tubes (a little nipple sticking down from the float bowl) ? Consult the manual to see for sure.

If so, figure out how you can hold it up straight for a while (center stand, wheel jack or a buddy). Remove hoses from overflows (if there are any) so you can SEE the individual nipples on each carb. Put petcock on PRIme and watch the bottom of the carbs. The one(s) in trouble should start leaking gas out of the overflow after a minute or so. Have something under the carbs to catch the gas. Put back to ON to stop the flow.
NOTE: Bike should ***NOT*** be running when you do this!


Remember that this may be an actual float failure. Brass floats sometimes develop leaks and sink instead of floating. Other types of floats can lose boyancy too.

At some point, you're gonna want to check that petcock to be sure the vacuum shut-off is working........but you may find that out while doing the above.
 
#23 ·
I couldnt find overflow tubes on the carburetors. There are drain valves but thats a screw.
I found out that the hoses that attach to the engine under the exhaust pipes is the PAIR system. This is the air supply. I wonder if the PAIR valve could be malfunctioning? This is right above the engine too, when it heats up some could this mess up something?

I can scan a few pages from my manual if you would need to check that out. I think i understand from the manual how to adjsut the floats.

The floats are plastic by the way. I can take them out and submerge them to see if they take on fluid.
I guess I have to take the carburetors off again... Ill do that tomorrow morening after i get off work.
 
#24 ·
I couldnt find overflow tubes on the carburetors. There are drain valves but thats a screw.

I wonder if the PAIR valve could be malfunctioning? This is right above the engine too, when it heats up some could this mess up something?

I guess I have to take the carburetors off again... Ill do that tomorrow morening after i get off work.
On my Zuki, the drain tube and the overflow tube are one in the same (the one tube serves both functions) but I have a different model. An overflow is an open tube that extends through the bowl to a level ABOVE the normal fuel level. On mine, the drain screw drains into the bottom of said overflow tube.
You should be able to verify this when you have the bowl(s) off.

If I understand the PAIR valve correctly, it is not likely to be the problem.

At this point, if "I" were in your situation, I think I'd just get new needles and valve seats and replace them all while the carbs are apart and probably new floats too. (unless you find the floats badly out of adjustment).
 
#26 ·
I went to the suzuki shopw and talked to the service manager. I described the problems and what I had done,
He was sure it was the float needle. He told me they get kind of expensive. Its only about a centimeter long though. Stupid expensive specialized parts.
He said they are rbber tipped and he said if they get damaged just a little bit they can leak. When i inspected them the rubber seemed intact and didnt have any significant deformation. To my knowledge they have never been replaced, he said they like to replace them after about 5 years. He said if i brought the bike in they would synchronize the carburetors and everything. Told me parts and serivce could be about $400.
The needle float needles could be as much as $200 fo a set of 4 or less depending on the type.
I can replace the needles but i cant synch carburetors if they need synchronizing.
Do i really need to synch them?
 
#27 ·
That sounds like a complete load of BS. Check with Blade here before you do anything. $200?!! You could buy new carbs for that! Plus, it's probably a one-hour job to swap them. $200 for labor is a major reaming.
 
#29 ·
Given shop labor rates today, that is probably a realistic quote.
Don't forget to change that contaminated oil !!!

If you do the carb work yourself, the sync takes an hour or less on most bikes so that would run you about $80. If it seems to run good, the sync is a desirable thing but not really necessary.
 
#31 ·
Wow all this old post seems to me just like the 2001 Suzuki gsf 1200 Bandit that I just purchased with 21175 miles on it and for $500 because the guy who sold it to me told me that he never could get it running properly and last time he try two years ago the bike let him stranded and pushing...well here I am everything been described plus more. I am Costarrican and had always worked in dirt bikes plus some raptors 700 here in the USA but this 4 in line carbs and this bike my respects. First I got a new battery, take carbs apart and clean and adjust jets and floats (all four were leaking gas) there was 3 gallons of gas mixed with oil in the engine, also the depurator pipe valve was filled with oil gas stinky mixture, set the mix screws at three turns as the manual says, float height at 14 mm to achieve the liner issue, new standard spark plugs, new high flow oil filter, new air filter, new gas petcock rebuilt kit...put everything together and bike fire right up didn't even need the choke but I did notice that it was a lot of black grayish smoke that irritates your eyes pretty fast and bad but anyways I thought well I need to ride this bike to maybe clean out everything and warm it up.
 
#32 ·
The bike runs fine but then I notice it was kind of bogging so come home pull the new spark pugs apart and they were cylinder 1 burning fine and all the other other 3 cylinders really black carbon fouled so I set the mixture screws to 3 and 1/4 of a turn, check the TPS and mount two new ignition coils from another Bandit well the bike didn't improve much except that now all the 4 cylinders seems to be carbon fouled but luckily and thanks to the clear gas filter I was able to check than when the bike start kind to bog it was because less fuel was going to the carbs and when it stalls it was because the fuel completely stopped (mmm very interesting) I do notice that bike had get a Yoshimura exhaust installed but jets were the same manual specify for the carb but anyways bike is extremely rich even at 3 and 1/4 of a turn plus sparks carbon fouled but now I have to figure it out also a gas delivery trouble, gas is fresh the superior quality with 1oz of sea foam per gallon (is sea foam the trouble?) I also found a gas cap valve system totally clog that I take a part and clean really well thinking that that was the solution of one of my troubles but not gas just stop getting in to the carbs when hot more probably and I also have found out that if I put air in to the thank thru the gas cap breather hose I activate the gas flow again and can ride fine until it happens again. About the carbon fouled sparks I even perform a cylinder compression test, they all were fine 135 psi, 140 psi, 150 psi and 145 psi in that order. Now I am running at 3 and 1/2 turns in screw mixture and bike feels great and sounds amazing while stills getting fuel, eliminate this in line filter that the manual actually suggest to install but I realized the petcock already have two filters that were in perfect shape but still running with 4 black carbon fouled spark plugs and a bike that let me stranded any time but not for too long now because all I have to do is removed the set put my finger in one of hoses and blow air thru the other a bingo I get fuel in my carbs to keep going...but really don't know why this bike is doing that I will appreciate any suggestions or how the person that start this post solved his trouble. I haven't sync the carbs but I did got the tool already...but don't think that will solve my issue!
 
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