My Bandit 400 broke down :(

[IanZW95]

Hey all,

So, I left the garage yesterday morning at  about 7AM on my little bandit 400, after I let warm up for about 10 minutes, and everything seemed fine for a few miles. As I started to go through a sweeping left I felt the bike "cough" and I was jolted forward, I was of course concerned but all seemed well afterwards because the bike went right back to running normally. Just as I thought to myself that I would pull into the parking lot of the high school around the corner the bike slowly sputtered to death and I had to pull out of traffic. At first I thought I may have been an idiot and run out of gas, but when I could hear that I had plenty left in the tank as I was pushing it down the road. so guys, any ideas what may be wrong? my guess would be a clogged fuel line, but I figured I'd get your opinion since I'm very new to the bike.

Thanks in advance,
Ian

[IanZW95]

A friend was telling me that I should make sure the vent on the fuel tank isn't clogged, but I dont know where it is on the bandit and I cant find any info about it on the google machine.

[bullet5]

Hello there

When it coughed the first time was the bike at low rpms <4k or higher?
What country are you in and what are the temperatures like at the moment?
If it's 5 and below at the moment (degrees celcius), then your problem may well be carb icing.

It sounds like a fueling problem, however that would make the bike die at higher rpm's not when you reach idle/below 4k.

All the best,
Bullet5.

[interfuse]

I'm going to start with the simple things.

Did you try switching to fuel tap to reserve "RES"? Reserve gives you access to the last few liters of fuel in the tank. You could very well have run out of gas on the main line but still have gas in the tank.

[IanZW95]

I tried flipping the petcock over to RES, but it still wont start. Although it is winter here in the southeast U.S. it was mid 50s when this happened and its been mid 60s with highs in the 70s (Fahrenheit) and I was in the mid range of RPMs as I was cruising at about 50 in 4th if I remember correctly.

[pawnee]

I'm not real familiar with the B4 but have you looked inside your tank for condition? As in rust. You could have a fuel restriction.

[IanZW95]

There doesnt seem to be any problems in the tank, its still nice  and shiny on the inside, but I cant see the whole thing. the manual says to remove the fuel line from the carb and try to start the bike to make sure that fuel is getting to the carbs, but Im not sure which is the fuel line and I dont want to just go pulling things off, so can anyone explain to me how I can find it or post a photo of it?

thanks,
Ian

[bullet5]

What year and model (standard or VVC) 400 is it?

Due to not knowing which you have I'll post the most likely...

Here's a '92/'93 model and how it should fit together



Make sure that vaccum line is on correctly and isn't split.

The fuel line runs down the back of the carbs. So it's a simple job of pop the tank off (not very heavy on these 400's) then put a small container onto the fuel line, hold it upright with fuel in and give her a crank. Don't let the fuel sit there too long before cranking otherwise you'll flood the engine.

Here's how the carbs go together



The above information should be almost exactly the same for later models of 400.

Bullet5.

[IanZW95]

What year and model (standard or VVC) 400 is it?

Due to not knowing which you have I'll post the most likely...

Here's a '92/'93 model and how it should fit together

its a 1992, not sure what model exactly, but those pictures are pretty much exactly like what im looking at. very helpful, thanks. Ill have a look at the vacuum line in the morning.

[Sean]

Switching the petcock to "prime" should trouble shoot the condition of your diaphram suddenly.

[IanZW95]

So, all the hoses look to be in good shape, but still no start. I just took the air box apart to find it (the foam filter and mesh screen) dripping with fuel, could this cause it not to start? Of so, what is the problem?

[bullet5]

Sounds like you've flooded your carbs. Are you sure the liquid in the airbox is fuel and not engine oil? The airbox should have a drain pipe coming out the bottom of it, so first find out what's blocking that.

If it is indeed fuel, then pinch your fuel line over night, leave the throttle wide open, remove the spark plugs and drain the airbox.

This should clear all fuel vapour out of these parts by morning, when you can try turning it over again.

[IanZW95]

Shit, you're right, it is oil, I just got some on my hand. That's worse isn't it?

[IanZW95]

Oh, never mind, I'm an idiot.  just found out  a little oil is normal, but should there be a puddle of it at the bottom of the air box?

[bullet5]

Oil is nothing to worry about

There's a drain from the top of the engine to the airbox as an overflow. There should be a pipe coming down from the airbox. (Can't remember if the 400 has one of these, but I'm pretty certain it does). That should allow any fluids in there to drain away when you remove the bung from the drain pipe. This saves taking parts off the bike to get to the airbox to drain it that way.

Proceed to remove the plugs, pinch the fuel line, turn the fuel tap to "normal", drain the airbox and carb float bowls overnight. This will make sure your carbs aren't flooded with fuel.

What position was your fuel tap in when you were riding? You should not ride around with it in the "prime" position as fuel will freely enter the carbs and overflow even when riding. "Prime" should only be used for garage maintence and to get fuel to the carbs when it has been stood a long time. Never leave it parked and switched to prime.