1996 bandit 250 bogs down.

[GOONR]

Once my bike warms up it will bog down between 4-7k rpm making commuting a right royal pain. Moving off from lights is real hit and miss, rev the crap out of it and hope that it moves. If it doesn't it will bog right down, sit at about 3-k rpm and go absolutely no where.. Not great when you have cars behind you.

I have had the carb's balanced, before that I couldn't get it to idle without stalling once it had warmed up. I've got new plugs in it as well.

What dya reckon is my next thing to check, I'm guessing it's still a carb issue but seems I've never taken one apart before I don't really know what I should be looking for. Plus I don't want to totally bugger it up, start with the most likely & (hopefully) cheapest bits and work up from there I guess.

When the engine is cold it is really nice to ride, no issues no drama's.

[TripleZee Dyno]

Once my bike warms up it will bog down between 4-7k rpm making commuting a right royal pain. Moving off from lights is real hit and miss, rev the crap out of it and hope that it moves. If it doesn't it will bog right down, sit at about 3-k rpm and go absolutely no where.. Not great when you have cars behind you.

I have had the carb's balanced, before that I couldn't get it to idle without stalling once it had warmed up. I've got new plugs in it as well.

What dya reckon is my next thing to check, I'm guessing it's still a carb issue but seems I've never taken one apart before I don't really know what I should be looking for. Plus I don't want to totally bugger it up, start with the most likely & (hopefully) cheapest bits and work up from there I guess.

When the engine is cold it is really nice to ride, no issues no drama's.

Sounds like its running rich for some reason.
Presume it used to be OK?
First things first, get yourself a manual or get onto one of the bike specific forums if you havent done this before.
Check that the enrichner is working properly, clean the carbs, no loose bits floating around, check float levels, check diaphragm, see how that goes.
It can be a long winded process and there arent any magic answers
good luck

[CookMySock]

Is the exhaust tailpipe real sooty and black? Does the exhaust spit any black smoke at any time? Did the new plugs make a temporary improvement? Does it get a regular open road workout? Does it idle perfectly, warm or cold? Does the choke make any difference when you turn it on or off? Check the rubber boots between the carbs and engine, for cracks.

Steve

[GOONR]

Is the exhaust tailpipe real sooty and black? Does the exhaust spit any black smoke at any time? Did the new plugs make a temporary improvement? Does it get a regular open road workout? Does it idle perfectly, warm or cold? Does the choke make any difference when you turn it on or off? Check the rubber boots between the carbs and engine, for cracks.

Steve

Yup Sooty, so it's rich then...

New plugs seem to have made a slight difference. Doesn't get on the open road much but gets a daily ride over the bridge at 12k rpm. Idles sweet as now that the carbs have been balanced. Never used the choke, never had to. Will check the rubber boots.

Ta.

[CookMySock]

Yup Sooty, so it's rich then...

New plugs seem to have made a slight difference. Doesn't get on the open road much but gets a daily ride over the bridge at 12k rpm. Idles sweet as now that the carbs have been balanced. Never used the choke, never had to. Will check the rubber boots.Since you dont need the choke, I'd check it's not stuck part way on. The bike should be a bitch to start and ride with no choke - in the winter anyway. Have a play with the choke mechanism and make sure its free. If there is a choke cable, give it a tug at the carb end and see if its slack. I doubt its the boots if the bike is running rich - thats a lean thing.

Steve

[GOONR]

Since you dont need the choke, I'd check it's not stuck part way on. The bike should be a bitch to start and ride with no choke - in the winter anyway. Have a play with the choke mechanism and make sure its free. If there is a choke cable, give it a tug at the carb end and see if its slack. I doubt its the boots if the bike is running rich - thats a lean thing.

Steve
It's never given me any hassle starting it, first stab of the start switch, little blip and it's good to go.

I'll check the choke. It is a real bitch to ride once it's warmed up and seems I've only been riding a few months I want to concentrate on my riding rather than stopping it from bogging down.

Thanks for the help, cheers DB.

[Ragingrob]

Nothing of additional help here, but it seems to be a common problem with these bandits! There have been a few similar threads on here and my mate has exactly the same problem, the bike just bogs down like anything and wants to die out.

He doesn't use the bike all that much and it ends up sitting in the garage, when he's ready to use it it just won't start without another full cleanout of the carbs of all the crap that's been sitting in them. When it finally starts it'll be all good for a little while but then slowly work it's way towards bogging down again till it gets unbearable.

It's as if the jets or something just slowly clog up.

:weird:

[GOONR]

Sounds like its running rich for some reason.
Presume it used to be OK?
First things first, get yourself a manual or get onto one of the bike specific forums if you havent done this before.
Check that the enrichner is working properly, clean the carbs, no loose bits floating around, check float levels, check diaphragm, see how that goes.
It can be a long winded process and there arent any magic answers
good luck

Ok, Choke is the first thing I will check. I've never opened up a carb before, if I have to I'll take loads of photo's as I go along as a reference so I know it's all going back together in the right order.

Cheers.

edit: yeah, it used to be all Ok. then it started running shit and stalling when hot. got the carbs balanced and that made it loads better but not perfect.

[GOONR]

I've checked my choke, I can hear a click noise from the carbs when I shift the choke lever around it sounds like it's engaging and then releasing again.

I noticed something today though, it's the first day in ages when the weather has been Ok and not raining or threatening to rain and it's much warmer than it has been. On the way to work the idle would be anywhere between 1500 (normal) and just a peak over 2000, it would change at every set of traffic lights. It wasn't as sluggish to pull off but still not good.

[imdying]

Is something aritificially choking it? Blocked air filter? Blocker air box inlet?

[avgas]

i hate to say it but i have had similar issues in the past......and they can be literally anything.

to add another..."could it be"....valve clearances - when were they last checked. usually not a huge problem but have noticed a few 250's lately, looked mint.....but it was deceiving as the motors had over 100,000ks

[GOONR]

Is something aritificially choking it? Blocked air filter? Blocker air box inlet?

I've looked at that and it all seems to be Ok, the air filter isn't black with shite or clogged as far as I can tell. I thought about taking the air filter out after I've run it home and have a quick blat up the street. See if that make's any difference.

[GOONR]

i hate to say it but i have had similar issues in the past......and they can be literally anything.

to add another..."could it be"....valve clearances - when were they last checked. usually not a huge problem but have noticed a few 250's lately, looked mint.....but it was deceiving as the motors had over 100,000ks

No idea when they were checked last, the bike has about 37,000 on it.

I'm new to the mechanical side of life, can't afford to take it to a mechanic every time I need something checking so will have to learn how to do it myself.

I can follow instructions and such like but wouldn't know where to start to check the clearances. Is it a difficult job. I've looked online for a workshop manual for this bike but can't find one anywhere.

[imdying]

No, not a difficult job. Yes, a time consuming pain of a job. Not difficult though, just keep a weekend aside if you've not done it before.

[meowmix]

A mate of mine has had two Bandit 250s (First one was run over by a cager) and I tried using it, it needed a hell of alot of balls to get off the line in any sort of hurry, or it would be stuck under 3000ish much as yours does.

His first one would puff some white smoke at higher RPM. They seem to run hellishly rich, He couldn't even start it one cold night at about 10-11. Had to wait till morning (and get a tow in the mean time).

I wouldn't go too far without a filter, or at least put stocking material over where the filter was. That might actually be a pretty good short range test, instead of bogging, it should feel reluctant instead, more like engine braking.

[GOONR]

A mate of mine has had two Bandit 250s (First one was run over by a cager) and I tried using it, it needed a hell of alot of balls to get off the line in any sort of hurry, or it would be stuck under 3000ish much as yours does.

His first one would puff some white smoke at higher RPM. They seem to run hellishly rich, He couldn't even start it one cold night at about 10-11. Had to wait till morning (and get a tow in the mean time).

I wouldn't go too far without a filter, or at least put stocking material over where the filter was. That might actually be a pretty good short range test, instead of bogging, it should feel reluctant instead, more like engine braking.

If I ride it home normally then take the filter off while it's still hot I'd only need to go about 1k up the road to be able to tell if it makes made any difference.

I'm going to give the carb cleaning a bash over the weekend, just will have to take my time and make sure they go back together again!

[meowmix]

Good onya. You just need a good screwdriver set, pliers etc. and remember to be gentle with everything, float levers bend pretty easily and diaphragms are pretty good at tearing. Then only do one at a time, or have an egg carton handy to store the bits seperately. Good Luck withit.

[nadroj]

"I wouldn't go too far without a filter, or at least put stocking material over where the filter was". - Bad idea - stocking will not let enough air flow thru just the same as a clogged filter!

[GOONR]

"I wouldn't go too far without a filter, or at least put stocking material over where the filter was". - Bad idea - stocking will not let enough air flow thru just the same as a clogged filter!

That surprises me, maybe my filter is poo then, it's not like filthy black but it's not white by any means!

Oh, I finished work late so didn't try taking the filter out and go for a blat, thats a job for tomorrow morning now.

[meowmix]

"I wouldn't go too far without a filter, or at least put stocking material over where the filter was". - Bad idea - stocking will not let enough air flow thru just the same as a clogged filter!

Crap, I didn't actually think a stocking was more restrictive than an old paper element filter! Guess theres nothing left but to wait for a clear pollen free day.

[CookMySock]

Guess theres nothing left but to wait for a clear pollen free day.Pollen wont hurt it. It's sucking up a pebble flicked up by a tyre and jamming an inlet valve open, only to be collected by a piston.. THAT will hurt it.

Steve

[GOONR]

Ok,

When I looked at the carbs they have obviously been given a really good clean when they where balance, spotless inside. Tried it without the air filter, not much difference really. So I moved the needles down a notch, runs much much better now. The thing is they are now on the last notch, I guess this means that I have just masked the real issue.

Edit: The top was quite loose on one of the carbs and the rubber boots weren't that tight either.

[meowmix]

Good that its running better with the dropped needles, and kind of points to the other end as the problem with the non-filter run showing little gain. Maybe you could take the headers off and see if there is excess carbon in the head or headers? The hunt starts to get vague when the intake is fine.

[GOONR]

Good that its running better with the dropped needles, and kind of points to the other end as the problem with the non-filter run showing little gain. Maybe you could take the headers off and see if there is excess carbon in the head or headers? The hunt starts to get vague when the intake is fine.

I wouldn't be surprised if there is crap in the headers, judging by the tail of the pipe.

How would I clean that out?

Cheers meowmix.

[CookMySock]

I'd give it a good hour-long run now, and see what it did. Don't cane it hard, just a nice open road cruise at the speed limit. See if the exhaust colour clears up a bit.

If, ten minutes down the road it didn't feel right, then come back.

Steve

[GOONR]

You mean I have to go for a ride, Oh well, if I have to. :woohoo::D

[Ragingrob]

And you checked all the jets were completely clear?

[GOONR]

And you checked all the jets were completely clear?

Looked Ok to my untrained eye.

[Ragingrob]

Looked Ok to my untrained eye.

I thought I cleaned the carbs out properly on the growler but it was still bogging down like anything. Didn't realise I was actually meant to remove the jet needles and fully clean them out too haha I'd just cleaned the carb bowls. So I blew out the jet needle until could see right through it cleanly and the bike was mint.

[meowmix]

Yep to clean the carbs well you pretty much need to remove anything that you can. Then clean with a very soft brush fresh petrol or carb cleaner, and blow down all the oles you can find with compressed air, taking care to not damage anything.
A good long ride should help clear up a bit of the zorst if its clogged with freshish stuff, but carbon does build up over time and if thats the problem no amount of riding will get rid of it. I haven't removed any myself, most just say you need to physically remove it. That might mean a small stiff plastic brush? Maybe a brush dremel bit? But I'd test it on some scrap alum to make sure it doesn't score it.

[gwigs]

Hey Goonr I,m In Birkdale if you want someone to have a look at it if youre still having probs.....PM me...

[GOONR]

Hey Goonr I,m In Birkdale if you want someone to have a look at it if youre still having probs.....PM me...

That's a really cool offer, cheers. The bike has been locked away most of the weekend, wife, kid blah blah so haven't had the time to see how it's really running now. Will deffo give you a shout if I need to. Beer and BBQ would be provided :yes:

Cheers!

:niceone:

[The Everlasting]

Did you end up finding the problem? Just curious..:)

[GOONR]

Did you end up finding the problem? Just curious..:)

Don't think so really... I've dropped the needles in the carbs. This has helped heaps and means that the bike is actually usable now. albeit with a little less power and it is still not smooth from a standing start once it has warmed up. It kinda stutters till about 7k rpm then it will take off. Pain in the arse on hill starts, people around me must think I'm demented. Revving the tits out of it then crawling away...

It's getting a service from Motorcycle Doctors a week on Tuesday. I've mentioned this problem to them and part of the service is that they sync and adjust the carbs, so they are going to do this and then see what's what.

Watch this space, I'll keep ya posted.

[The Everlasting]

Oh okay,i was just reading up on threads related to bandits,and came across your thread.

That stuttering until 7k would be very annoying,normally something like that would point to plugs/leads fuel problems...


but yeah,keep us posted.

[GOONR]

Oh okay,i was just reading up on threads related to bandits,and came across your thread.

That stuttering until 7k would be very annoying,normally something like that would point to plugs/leads fuel problems...


but yeah,keep us posted.

Yeah it's a right royal pain in the arse. Hill start's give me the shit's if you don't give it enough rev's and slip the clutch a tad it bogs down and you run the risk of a SUV up the bum.

Not cool.

[skinny]

Not as to keep re-living the past but how did you go with the last service? My bandit is not going the best with the same problem. Today it decided it would just loose power and die on the way to work. I think its fouled itself cause it wouldnt start so left it at some random warehouse and will go play with it after work.

[GOONR]

Not as to keep re-living the past but how did you go with the last service? My bandit is not going the best with the same problem. Today it decided it would just loose power and die on the way to work. I think its fouled itself cause it wouldnt start so left it at some random warehouse and will go play with it after work.


Got George from Motorcycle Doctors to Look at the carbs and give it a service. He spent quite a while working on the carbs, when he came back from his test ride saying it was like a new bike I was a bit pessimistic, but wow!, he was not wrong. Fantastic. He did mention that I would need some new emulsifiers (I still don't really know what they are) at some point cause mine are on their way out big time but the work he has done was great and has made a huge difference. Well recommended.

[skinny]

Thanks for the info i will have to check them out. I just took mine to the local bike mechanic who basically did nothing to the bike. Its actually running worse, think
he gave up or just didnt have time.

Luckily he only charges me $40 for parts but he had it for a week.