My first guess...your brother let the machine idle 20 seconds, hit the throttle and partially blew a carb loose from an intake boot.

 

the valves needed to be adjusted, so I did that, but it still won't start. I checked all the boots and they are all tight. I checked to see if it was getting a spark and it is. It is getting gas, because the plug was wet. I'm starting to think it is some sort of electrical problem because it has trouble cranking. I thought it was the battery at first, but we put my raptor battery in and all it did was make this chattering noise and sometimes it would turnover but not all the time. it vibrates where the fuses are when I try to start it. does this sound like a bad starter? I don't have any experience with starters since mine never had problems.

 

You could always take the starter out and bench test it. Have you re-jetted it or messed with any carb settings. Have you checked everything for leaks? Around the heads? Have you tried changing out the CDI boxes and trying that? If its not getting spark, then its most likely something electrical [img]i/expressions/face-icon-small-smile.gif[/img]. Might need to download the wiring diagram and make sure nothing is shorted out. I had an old XR100R that would not get fire for anything, we check everything. Finally we found that the killswitch was f*cked, and it was causing it to ground always. Have you checked some of the electrical systems with a multimeter? You can could check the ignition coil, could be a messed up spark wire. Good luck, I hate when my machine won't run.

 

Does it have any compression?

 

maybee you blew a hole in the piston or bent valve?

 

friend has a problem with stator. Has had it replaced twice and keeps going out. Will not start until stator is replaced. Dont know why or how. very irritating problem.

 

I spent 30 minutes trying to get my raptor to start one day. Finally looked and the carb boots were both off. More often than not that's the problem.

 

I checked all the carb boots and they are all still nice and tight. the only aftermarket thing he has done, that would effect the quad's engine, is the K&N air filter. how hard is it to change the starter? I have one of them manuals downloaded to my computer, so should I just follow that?

here is what happens when we try to start it:
we push the start button and all it does is chatter near the fuses. sometimes it will crank over but it is usually only a couple of times. we tried a new battery, but that didn't help.

 

is your battery dead, is your fuel on. often it is minor things like this that will cause your atv not to start.

 

I know that if your parking brake is engaged your raptor wont run right, found this out on monday ha ha