Hey Guys I am new to this forum and wanted to help my friend get his Honda 400ex back working. I do not have a quad and dont have much knowledge on them, but I will explain to you the problem. Okay When my friend is starting his 400ex, you know turn the key on and when he presss the electric start the electric start does not crank over trying to start the engine. We tried roll starting it and that also did not start the engine. My friend's dad think its the spark plug, but wouldnt the electric starter crank even if the spark plug was bad?? Do you guys think it might be a combination of a bad Battery and spark plug?? When looking at his quad I found the yellow seemed to be spark plug off the quad just dangling there. I asked him and he says his dad disconnected it, but when we press the electric starter shouklldnt the spark plug ignite and burn red??? I have very little knowledge on quads but do you guys think this problem is due to a battery?spark plug issue? I asked around at Pbnation and one suggested to take it to a shop, but its not my quad so I can't. Is this an easy fix or something alot worse? Thanks a ton, Chris

 

Yes the bike should turn over even if is has no fire or the spark plug is bad ..The bike won't turn over/start unless it is in neutral & the kill switch on , but I'm sure your buddy knows how to start his bike ... Do you have a volt/ohm meter to check the electric system..?.

The spark plug is hard to change on the 400EX without the spark plug wrench in the tool kit ..

 

Yes I believe I have a volt meter if not I will buy one, but what should I check for in the system such as the battery? Also The yellow spark plug was off dangling infront of the motor, I dont know how my friend's dad did it but it was off. I think it is the battery it has to be or something deeper in the electrical system, but HOndaMechanic what should I check with the Volt Meter??

 

First thing that comes to mind is a blown fuse. Do the headlights work??? The headlights and starter are on the fused circuit.

Even with a blown fuse, it should push start! Be sure you have the key on and the kill switch is on, when you push start.

 

Yes ..Check battery voltage , I believe there is only 1 fuse 15a , power at solenoid .. What is your email address and I will email you a couple of sections from the TRX400EX PDF shop manual ...

 

my email is cmarthers12@yahoo.com, I will se if the headlights work but I believe they do. Also how do you connect the spark plug so we can try push starting the quad just to see if its an old battery?? THanks for all you guys help

 

what i had to do with my trx 250ex is pull the seat off and where the wires go from the battery to the starter touch a screwdriver or a wrench to both and it should make a power transfer through the wrench or screwdriver and will tell you if its the battery or not and dont be afraid it will nor shock you it might spark once but it should start

 

does it have any compression?