400 backfireing

[Troy15x]

My 400 started fine this moring. I took off the stock headlight switches and starter button and replaced it with a kill switch from a dirtbike.

The 400 turns over but then backfires????

If i switched the + and - cables would it do this??

Please help:confused:

[400ex28]

sounds like its runnin lean ;)

[Troy15x]

im not going to disagree, but it was starting fine before I change starter button

[cals400ex]

what pilot jet you running? what ignition box you running?

[Troy15x]

I think I know the problem

I believe that when I took the stock starter box off, that the ON/OFF toggle switch was off. I have not tried yet but could this be it??

The bike turns over and then backfires NEVER STARTS:confused:

[Troy15x]

what pilot jet you running? what ignition box you running?

I really don't know the pilot jet size but I know that a shop just put it in and it was running GREAT before i changed the button

Also I have a stock CDI box that is also brand new

[400exredrider]

if it starts its not the kill switch unless the kill switch is shorted out and cuts the engine off, but its prolly lean

[yfz450rider29]

Does nobody read what he wrote??? He said it dosn't start, and it was runnning fine before it happend. If I was you i would change the spark plug cuz of the backfireing....not good for plug. And then i would put the stock setup back on and see if it works. If it does then it was because of the new starter setup.

[400exredrider]

YZF,, yeah he did say that, but could it possibly not want to start because its too lean,,, i think its a possibility,, i just said what i thought because i cant do a thing unless i witness what is going on. throwin a new sparkplug in everytime dont always fix things, i know you may have thought this as a little kid but aslong as the spark plug is sparking,, Which CAN be tested by taking it out and holding it against the head, if it sparks more than likely if the engine is getting fuel and air it is going to start... just my 2 cents but spark plugs arent like ductape, they can not fix all:o

[yfz450rider29]

If everything was running fine, and all he did was change a switch i doubt that would lean it out. And If you read what i wrote i said to change the plug cuz it kept backfireing, that dosn't help the plug perform. I didnt mean to be mean at all but he said a couple times that it was running great before.

[Troy15x]

I re-wired the whloe quad and took of all the wire i did not need. I just had some bad connections. Now it is back to running and the spark plug was pretty bad so I changed it too.
Thanks for your help:D

[TravEX]

good call YFZ!,,,the spark plug is always a quick and easy way to start,,,took me a while to learn that on my 400,,,

[rYan01400EX]

Don't let it backfire long, it'll blow the manifold gaskets.. This happened to my cousins...

[ilovemymxer]

Originally posted by cals400ex
what pilot jet you running? what ignition box you running?

my boyfriends bike did the same thing. his bike was waaay to lean. so we made it like a crap ton more rich and it runs great.

[crazyracer250r]

it happened to my friend the metal going round the handle bar from the kill switch is grounding the motor out take it off wrap some tape round the handlebars thentry it i promise itll work