www.zxrworld.co.uk

Hey ..

My ZXR400 L1 started burning when i put my carbs and spark plugs back on, tried starting for 10 minutes..
It smelled gasoline and then it came big flames up for under the gas tank.

I killed the flames and i dont know what happend, and i dont know what to do !

Get the tank off and have a look. Chances are if you could smell fuel then that could well be the cause of fire.

Id have a go starting it with the tank off so you can identify where a leak may be coming from.

Sorry for the lack of information yesterday..

All of the fairings was off and i just finished cleaning and "repairing" the carbs ..
(repairing = changing gasket and fuel filter and the float needle)

I had a problem with fuel "leaking" from the bottom of the carbs, but now the didnt leak from there. Because i fixed the drain plugs and adjusted float heights .
Now it came gasoline from the orange hose between carb 3 - 4. I thought maybe it was a vacuum hose or something.

This is not my photo, (ignore the arrows, i mean the orange hose on the right side)



I did take the tank off after the fire was killed, and noticed a part off the air filter was burned.

My theory is that the hoses from the coil to the sparkplug is bad, ?
Beacuse they look very old and 2 of them have electric tape around them.
I noticed small cracks in the end rubber.

Maybe the spark came from one of these. ( i ordered a second hand set of hoses and coils from ebay yesterday.)
They look much better ! (on the picture)

I also ordered a new air filter and fuel filter and a new set of spark plugs ( because mine is black)

You should know that i bought this bike in Oktober 2012 and i havent had a oppertunity to ride it.
And only had it running 2 times.

More info about the carbs and bike here:

http://www.zxrworld.co.uk/zxr400/worksh ... /carb3.jpg


Thank you for replying .
Really need some help.

the orange hoses are your fuel overflows - the one on the right drains carbs 3 and 4, your float height must be either set incorrectly (i.e. too high) or you have damage to the fuel float that is preventing from it sealing properly, as you said you recently changed these then i would imaging the float height is too high, it should be 11mm.

You can check the height by attaching a clear hose to the end of the drain hole and opening the screw. This will fill the hose till the level is the same as inside tge carbs. Iirc theres a marker line on the side of tgs carbs which it should go up to. That should confirm if the fliat level is correct.

What a great way to do it

Is it a mark on the side of the carbs ? on the outside ?


I found 2 meltet electrical hoses almost under the carbs..
I think one is to the fuel pump or something..

If i buy a full "electrical loom"? should those wires be there `?

Hey again, read the last post again and realiced that i should make the mark
quite emeressed


So i should make a 11 mm mark line where the gasket is, and check with the amount of fuel..
But it would be a different amount of mm, for what hose i use..
So i dont see how this will work ??

And does anyone think it is possable that the spark came from the spark plug wires (HT ?? )
And the air filter started burning ?

That atleast my theory

By the way.
Thanks for posting, i really need some help on this one ..

Rob is correct im afraid. There is a raised metal line about 5mm long on the right hand side of the carbs. Thats the line you use. Use a thinbore hose and a shortest length you can so that you dont get lots of dead volume in the tubing. If your floats are correctly set to 11mm this method will tell you if you have a sealing problem with the fuel float nedle.

As for the source of the fire. He airbox is a sealed unit so unlikely to be related to sparks or ht leads. Its either the fuel drippong onto the hot engine near to where the 300A of power goes into the starter motor...or possibly you got some kind of intake detonation that sent a flame into the airbox.

So the fire started with a backfire ?

I was giving alot of gas, and it would not start,so i think it was alot of unburn fuel somewhere..

I will change plugs, coils, air filter and the ht leads anyway

So the next step will be figuring out if the floats are correct.
The float needle should be fine, i changed the seat and the needle..

Hi again good forum


Will upload some pictures soon, but one of my spark plugs (old) is round i think, can not get i out..!!



Some advice? tecniques ?

Is the socket long enough? You could remove the cam cover and plug hole tubes to get you a bit closer to inspect.

i used the socket on the other 3 spark plug with no problems ..

but if i take off the cam cover, insent it hard to get off and on?
And the gasket and stuff...

And i have some F***ed electrics..

anyone know what this is ?



It is 2 off them, combining 3 cables each.
One red and blue (i think it is for the signal light in front.) but also one black thicker cable. (going into the radiator)




Those calbes come from the back of the bike, and also got melted in the fire.. hanging on the air filter breather hose (i think)
In the left corner you can se the rest of the burned cables, on to the fuel pump and one i dont know..

not sure about all those gubbins, if its wired into the sensor in the radiator i would suggest its probably a switch to turn the fan on if needed, its a pretty common mod for those worried about engine temperatures.

might be better to cut your losses and pick up a new wiring loom.

As for cam cover, there is a rubber gasket there, which should be fine, its is akward but not impossible.