Bike cuts out under load?

[JamesRoberts]

I had exactly this on my bandit 250, started under load up hills then eventually would die off the line unless you rev'd the shit out of it before letting the clutch out. Pulled the carbs and they were full of shit, a good clean of the carbs and new plugs and problem solved

[CookMySock]

might be a blocked breather in the fuel cap [excellent diagnosis and remedy trimmed]

I agree with this.

Quick check for this - when the engine quits, quickly open the fuel filler and see if you get an inrush of air - you will hear it go foooosh.

[Lus7]

http://i.imgur.com/nnd0E.jpg

Ok so what do these do?
The big hole is my air intake i gather because when I block it the bike turns off.
the line i'm holding doesnt do anything when I block it, but its connected right to the carb so i'm guessing it's important.
the line hanging off isn't connected to anything, but it's connected to the air pod

What are they?

[Lus7]

ok, so I just put the filter back on and rode the bike to the gas station.

Everything seemed fine.

Put some gas in, started the bike. it had itself a little power fart but it was alright after that.
I'm still convinced something is wrong with it, seems to be burning a lot more gas than it has the entire time i've owned it as well.
hmm

[FJRider]

ok, so I just put the filter back on and rode the bike to the gas station.

Everything seemed fine.

Put some gas in, started the bike. it had itself a little power fart but it was alright after that.
I'm still convinced something is wrong with it, seems to be burning a lot more gas than it has the entire time i've owned it as well.
hmm

Did you clean the filter ?

[Lus7]

I cleaned it yeah, it decomposed a little when i soaked it in the soapy shit, so I've ordered a new one.
but it's going to be here on tuesday, so I dried and put the old one back on to see if the new spark plugs did anything.

ran it on idle briefly with no airfilter, then put it on and off to see if I could hear a difference in the engine sound. lol nothing.

[Lus7]

so sitting at idle, if i rev it really hard/suddenly it makes a pop and doesn't rev.

happens once every 20 revs

[FJRider]

so sitting at idle, if i rev it really hard/suddenly it makes a pop and doesn't rev.

happens once every 20 revs

From the tank there should be two lines running to (different places on) the carb One is a fuel line, the other the vaccum line which opens the fuel tap when the engine is started. If the vaccum line is not connected ... it wont run well.

[FJRider]

I cleaned it yeah, it decomposed a little when i soaked it in the soapy shit, so I've ordered a new one.
but it's going to be here on tuesday, so I dried and put the old one back on to see if the new spark plugs did anything.

ran it on idle briefly with no airfilter, then put it on and off to see if I could hear a difference in the engine sound. lol nothing.

Take it for a short run with no filter on it. See if there is any improvement. If it was the filter blocked ... it will run better. But it Will need a filter soon as you can ...

I doubt you will notice any difference in sound at idle with no filter (apart from intake noise ... thats the air getting sucked in)

[ducatilover]

Try it with the fuel tap on reserve or if it has a prime position too.

[FJRider]

Ok so what do these do?
The big hole is my air intake i gather because when I block it the bike turns off.

The line i'm holding doesnt do anything when I block it, but its connected right to the carb so i'm guessing it's important.

Most likely the overflow from the carb.

The line hanging off isn't connected to anything, but it's connected to the air pod.

It is most likely the breather hose from the crankcase to the filter pod. They can block the filter as the fumes can be oily ... most likely your problem. (the filter blocked, not the line doing it's job)

[ducatilover]

Most likely the overflow from the carb.

It's the vacuum/pressure reference for the bowls.
It needs to be in still air (under the tank should be fine) if it's getting proper airflow to it it will pressurise the carb bowls and it'll flood, if it's pinched or blocked the bowl pressure will be too low and it'll lean out and die.


It pays to triple check the fuel and vacuum line to the fuel tap, while you're there replace the vacuum line, it'll cost sweet FA and it won't hurt.

[FJRider]

It's the vacuum/pressure reference for the bowls.
It needs to be in still air (under the tank should be fine) if it's getting proper airflow to it it will pressurise the carb bowls and it'll flood, if it's pinched or blocked the bowl pressure will be too low and it'll lean out and die.

I stand corrected ...

[Lus7]

So i took my bike out for a ride and it's riding fine now
I changed the spark plugs and the engine sounds a little different

i'll update if something happens, but seems all good

i'll still clean out the carb and replace the lines

[Lus7]

Cut out this morning on the highway. pulled over and it wouldn't start again for 20minutes, almostshatmyself when the truck behind me flew passed
it's been a few weeks since I changed the spark plugs, not sure what's wrong.

When the throttle cable is too tight (or loose, I can't remember), it does this:
http://www.youtube.com/watch?v=obXYvH0UhHc
if that means anything


also, the last time this happened I let my tank run low. I filled up and the issue seemed to subside (although my bike feels a little underpowered)
I've let my bike run low again and this happened. I checked to see if it's the gas cap, but it doesn't hiss when I open it before/after it has cut out.

another thing, when the bike is cold, I can start it without the choke on but if I move the choke to the on position it will cut out, my mate's bike doesn't do that.