06 KFX 400 wont start - tried all I know

[bighause]

Checked valves (perfect), cleaned carb (it was very clean), replaced spark plug (it sparks). I haven't checked compression since my tester wont fit, but it sounds good when it cranks over.

I have heard of CDI boxes going out, I have an aftermarket one installed. Any chance that could be what's wrong? If it was bad would it still send out spark? I'm open to sugestions before I take it to the pro's.

Thanks

[cataway]

when you were tiring to start ,did you have the fuel petcock on prime ?
did the quad sit for a long time ?

[bighause]

I tried with it in all positions, and no it didn't sit a long time. Thanks though

[airmobile101]

Crank it over while you have your hand over the exhaust pipe. That will give yea an idea if its got an compression or not.

[airmobile101]

Oh, if you crank on it long enough and it still dont start,pull the plug and see if its wet. That will tell yea two things. One, you might be flooding it or your not getting the spark to fire it up.

[cataway]

will it pull start?

[bighause]

Haven't tried pull starting, I was unable to get it to start while coasting down a long hill. It did attempt to start though.

[cataway]

sorry but that is the classic sign of tight valves , are you sure you have them set right ?

[bighause]

I tried pull starting it with my car and it started but didn't run very well at all. I guess that I should re-check the valves? They should be .004-.008 IN and .008-.012 EX right. Do they normally get tight or loose?

Thanks for the tips

[cataway]

the reason the valves get tight is the coating on the valves
is wearing off ,you will be able to adjust then a few times
but in reality they are wearing out .
mostly its the intakes that are the problem ,there not very expencive but you do have to take off the head to get to them
,and to be honest with you the stock ones are as good as any.

[bighause]

Good to know, I appreciate the help.

About an hour after pull starting it, I tried to start it normally and it fired right up and ran great. What the heck? Tried it 3 separate times, started and ran fine each time.

[quad97]

If your battery is low at all, these machines will not start with aftermarket CDIs. And if you do get it running, they don't run well until the battery is charged. Put a trickle charger on the battery until you are sure it is fully charged and give it another try.

[bighause]

It has run fine since I was able to start it finally. Fires right up like normal and runs perfect every time. I'm not sure what fixed it?