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.

[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.