well i was going to go out riding tonight so i loaded my 400ex on my trail and towed it the the local MX track it was about 38 degress out. IT WOULDN"T START it just fired a few times then died in a secound now i was hualing *** to the tack so i think either i flooded the motor to the max or else i cracked my spark plug. i took it out and looked at it and it was soaked so i think i fouled it. what do you think?

 

I hightly dout you fouled it. did you use the choke to start it because if you didnt that might explain it.

 

If it was soaked with gas it will evaporate in just a few minutes. If it was oil soaked then that is a whole different problem. Rule of thumb on a single cylinder 4-stroke. Very good idea to change the plug often like every 3 months or so. Cheap insurance versus pushing a bike back to the truck.

 

Hey daniel! Not questioning your knowledge I am actually curious. I have never heard of changing the plug that often. If this is something I should be doing I think im out of the loop here. I've had my 400ex for a year now and have never changed the plug. I ride almost every weekend. Am I facing potential damage to the quad or is this just something you do to keep a fresh plug in to prevent failure.

 

It's just habit from a lot of years of riding old three wheelers and stuff. You won't do any damage by leaving your plug in. It only takes one fouled plug in the middle of nowhere to make you more cautious.
Some engines can run forever on a plug, some might only make it a month. Condensation and other factors can lead to early failure.

 

Is it even possible to foul a spark plug on a four stroke? I didn't think it was and have never heard of it, but then again maybe I'm just s dumb a$$[img]i/expressions/face-icon-small-smile.gif[/img].

 

I don't think it makes you a dumba$$ I thought the same thing until a buddy of mine fould one on his ex. I now carry one with me.

 

I just don't see how it would be possible to foul one, four strokes don't use premix it's just striaght gas.
If anyone could explain how it's possible I'd love to hear it.
Thanks

 

Ya I would like to know also.

 

Read this...spark plug fouling...it can happen to any spark plug..2 or 4 stroke...scroll down a little bit...