Replacing valve stem seals in frame?

[toddmac]

Hey guys,
Can I replace the valve stem seals with the head still on with a Warrior? I know on a car I can run air to the cylinder to keep the valves from dropping and then you can compress the spring and pop the keepers.
I have a warrior that smokes when she is cold but clears up very well as soon as it warms up. I am guessing they did a bad job on the upper end or the seals just crapped out. Supposedly the bore is only about a year old and the previous owner said it smoked before the bore. He told em to do the head but apparently they didn't.
I'm looking to try a quick fix before I end up having to get way deep into the motor and yank it out of the frame. Never had to mess with an ATV motor so I wasn't sure of you could do the seals with the head on or not, or if it's so simple to yank the head, if I should just do that with it in the chassis still.
Thanks!

 

[yamarider]

It would probably be less of a headache to just pull the head off, i've never heard of anyone doing them with the head still on with these.

 

[jasonp]

Yeah you could do this like a car. You basically have to pull the front plastics no matter if you pull the head or leave it on the bike. There is a special thread for the spark plug that you have to use. You can get it at any tool store and like you say put air to the head to hold the valve up. I recomend yamaha parts. I tried others and they don't work as good.