HELP please i feel dumb

[v0lcom13sn0w]

ok so we did a valve adjustment with the stock woodruff key in and the bike runs fine. we just put a sparks key in and now all it will do is backfire thru the pipe and will not start... any ideas????????? only thing i can think of is the valves are too tight now... just put a new plug in it.

[miles Machine]

putting the timing key in wouldnt make the valves tighter.

[grassman]

When I do my valves I dont use the marks on the flywheel... I take the valve covers off and turn the motor until the valves are loose and you are able to feel the slack with your fingers. From there I just use the feeler gauge set it and go... Ive been doing this to my 400 since I got it in 06 and have never had a problem... no bad ticking, hard starting, back firing or smoking. It may not be the "right" way to do it, but it works for me... $.02

[jasonwayne222]

well from what u are describing your doing it wrong. How can u assume you are exactly at TDC. You are just turning until your valves become loose. What u got to think about is you are probly adjusting the valves when the piston isnt exactly at TDC. It isnt a suggestion for the Piston to be at TDC its a necessity. Make sure it is exactly at TDC. Oh by the way did I mention TDC!!! You cant go off a hunch because your valves are loose so maybe im were I need to be. Dont think like that make sure you are exact when u do this.

[350ex]

Yeah dont do that. This is to precise of a measurement to just get it done "close enough"

[camaromitch]

When we set the valves on my uncles drag car we just kick the starter over until the rockers are loose to set the valves. It runs a small block chevy and shifts around 10000 rpms. Grassman's method works for us.

[350ex]

Well, Im not a mechanic but thats what I've been informed by people who I would say know what they are talking about.

[camaromitch]

And I'm sure that in ideal conditions that is the best thing to do. I haven't even set the valves on my 400 so I probably don't belong here, I was just adding that on my uncles car, with nothing to indicate TDC or BDC better than a loose rocker, that is what they use, and with the RPMs they run I'd think it'd be most crucial. There could very well be something different about the ex motors that make them more susceptible to damage from the valves not being right, just my .02.

[350ex]

Old school car motors are also a bit different. I guess that is how Ive adjusted them on old school chevy v8's. I've always just adjusted them until they are snug though. I believe the geometry is a bit different on a quad motor. Plus there is only one cylinder so you do have the ability to do it more accurately with the timing mark on the flywheel.

[camaromitch]

Yeah, I know if there was an easy way for us to check it knowing it was at TDC we would.

[v0lcom13sn0w]

soooo any idea why this bike wont start now that we put the sparks 6 degree timing advance key in? as i said before it ran perfect before we put the key in.

[350ex]

Forgive me but the sparks key advances the cam timing or ignition timing? Sorry I dont have an ex.

[v0lcom13sn0w]

ignition timing... oh btw i figured it out guys thanks for the input though its much appreciated:)

[350ex]

It was something simple right? Usually when I get puzzled on something Im looking too far into it and overanalyzing. When in reality its some small detail that I overlooked...:rolleyes:

[v0lcom13sn0w]

not enough valve clearence which is what i thought it was in the first place i have no idea how they got to be so tight. i couldnt even get a feeler guage in there so i adjusted them to spec and the bike runs awesome once again

[350ex]

Did you look at the valves. Thats usually a sign of cupped valves. If thats the case you should replace the valves. You might want to have a reputable shop check it out.