what are some of the symtoms of a bad cdi box or one that is "going" I have a 300 bayou which is amking a chattering or noise which comes and goes. it kidnd of sounds like somethig is rattling around insode the engine. I brought it to my local kawi. dealer 2X and neither time they didn't hear any noises, but as soon as I got it home the noise was there. when I explained it to them they thought it might be the CDI box going bad and the noise I was hearing was a spark knock ???? thanks in advance

 

Never heard of a CDI causing ignition chatter?

Every CDI I have had go bad, the motor will start to miss and then stop running. When they go, they won't start or run anymore.

 

That's what I thought about the CDI box, I'm checking the timing chain now to see if that's causing the noise

 

Yes, I think you are in the right direction - check mechanical stuff. Get your mechanic's steth scope and pinpoint the location of the noise. Could it be tight valves?

 

We checked the valves they seem fine. the noise comes and goes, does it at idle and at higher rpms. It basically sounds like a really loose chain clattering. I'll let you know when we figure it out

 

Two more possibilities:
1. Cam chain tensioner not working (extending out to tighten the chain).
2. Loose rivets holding the basket to the cetrifugal clutch housing.

 

we already replaced the clutch housing and the rivets were very loose, thought that was the problem, but apparently not

 

I have a polaris sportsman 500 I replace all the stuff from stator pick up coil an its been running fine until about a week ago now when i try to start it it givesme one spark and it quits what could be doing this i have even tride a new cdi box with no luck the pick up has 14.35 when i tested it. Its done this same thing before one day i just walked up tride it and it started

 

You don't say what year model you have,but pull the black wire from the reverse limiter module if it's a 99 or earlier model. If that doesn't help then pull the black wire from the cdi to isolate the kill circuit. If that helps on starting then the problem could be in the ignition switch,the left control switch or the cdi kill circuit itself. Plus you can ohm out the pulse coil white and white/red wires. Should be around 97 ohms. If it pulls starts easy,but hard to electric start,the gap of the pulse coil to the flywheel could be off. Here's what another member found out when he had that problem. no spark to plug when using electric starter - Page 3 - ATVConnection.com ATV Enthusiast Community

 

I'm having problem with my 2002 Polaris sportsman 500 ho, the seems to keep running burning it out. I noticed the black wire on the cdi box is rehooked to a toggle switch. If switched to off position it runs ruogh at high rpms and also won't shut off, yet when flipped it runs great but seems starter still gets power. Help please