KFX450 will not start!!!

[bball23]

Hey guys,

So I bought a 2008 KFX450R about 3 weeks ago.It started up fine all the time and didnt have any problems with it.Then I decided to change the tires,brak pads,and the chain and after I changed the stuff I started it once and rode it for a couple seconds and now it wont start anymore. I checked the spark plugand theres spark,its getting fuel,the starter is working fine.I thought it was the battery for a little but I connected jumps cables to my truck, charged the battery, and tried to push start it down my street and it wouldnt start.Sometimes its turning a little bit but then it doesnt turn over at all.When I took the spark plug out and checked to see if it would turn it was turning perfectly but when I put the spark plug back in it wouldnt turn at all. Everything seems good and I dont know what I should check next... I payed a lot of money for this quad and I dont know whats wrong with it.Has anybody ever had this problem? Please help and tell me all the stuff I should check and how to check all of the electrical and sensors or whatever I have to check.ANY HELP WILL BE GREATLY APPRECIATED!!!!

[kawi_34]

Under the hood, theres a black box called the Roll Over Sensor, that probably came loose, mine did, and alot of others also.

Zip tie that SOB down, but make sure you have it set the right way, there should be an arrow that tells you on the box which way needs to face up.

Goodluck

[bball23]

I might have to check that but today I took apart the side of the engine and where the gears are I took all that out and I found black aluminum pieces scattered around in there.Does anybody know what is made out of aluminum and is black in the engine? Also I tired push starting it today and the engine doesnt even seem to be moving all the way around and something is weird.Could that be the rollover sensor????I dont know what to do.Ill check that sensor tomorrow and is tht doesnt work then ill take apart the whole engine.

[bball23]

Also the second day I had it I was changing the oil and the oil was an aluminum color and I think it might be from the pices I found in there...

[kfx450_R]

not sure if you are having the same problem as me or not but mine woud try to turn over then just stop kinda like the battery was worn out but i could push start it and it would be fine. after ALOT of troubleshooting i pulled the top cover off the engine and on the end of the exhaust cam there is supposed to be a spring, that is your decompression spring. mine was broken so the starter couldnt turn it over all the time at full compression. i put in a new spring and working perfect now. not sure what you hav goin on but it may be something to check

[bball23]

thanks ill check on that

[bball23]

Hey,Kawi34,I was wondering how to find the rollover sensor...Is there a black box and does it say rollover sensor and how big is it.If you could post a picture it would greatly help.

[kawi_34]

The 1st picture is looking directly in the hole in the front plastic with the hood on, you can see my finger pointing right at the ROLLOVER SENSOR.

The 2nd picture is with the hood off the plastic, looking straight down under the wires, where my finger is pointing. Not on the top of the box, but directly in FRONT of it, it will say UPPER with an arrow pointing UP. This should be facing to the front of the quad and zip tie it down or use silicon, but preferably zip tied. For more details, its placed directly on top of the front plastic supports where you can see the 2 bolts in the 2nd picture. Let me know if you need better pics.

The quad is dirty from riding at the mx track, so don't mind it lol.