Tips for pulling the camshafts?

[Roadstergal]

I know some of you gurus must have some neat tricks to make it easier.

My GS500 is shim-under-bucket, so I have to pull the camshafts to do the valve adjustment (oh, I've been dreading the valves going out of spec).  Any tips on how to make this as painless as possible?  I still have all of the stock timing marks and the stock tensioner.

[gsJack]

Never heard of a GS500 with shim under bucket valve adjustment.  Did someone convert yours from shim over to shim under?

[Roadstergal]

Yes.

[ohgood]

i just read your post three times and wondered if i'd lost some (more) reading comprehension.

so, they do that eh ? ok. i'll watch this thread then.

[Roadstergal]

You have to pay moola to have it done.  Or buy a bike from someone who has paid moola to have it done, which is the way I like to do things.

It has a hot cam and a shim-under-bucket conversion.  And a few other things; it's a race bike.

[dgyver]

Align the cams and rotor normally. Rotate the motor backwards until the rotor tab points vertically. This will take the pressure off both cams. Back off the pressure of the CCT and now you can then unbolt the cam caps to pull the cams. You may need to adjust how far you rotate backwards depending on the timing of your cams.

It is only about a 1/8-1/4 turn backwards. Not a problem but you will be turning the starter as well. You may want to mark this point for future adjustments.

Since you are running hot cams, you would benefit with an advanced rotor.

[the mole]

It's going to be a PITA as you have to pull the camshafts....if they need adjusting. Check the clearances, you might get lucky! I would carefully check those clearances with the cam at different angles, work to the tightest clearance so they don't end up too tight. Also have a good micrometer to double check the thickness of the shims you're taking out, as well as the ones you're putting in. They're not always exactly what they say, and you don't want to have to pull those cams twice. Double check all measurements and calculations, good luck.

[Roadstergal]

For sure they're off.  Trust me, I've put this off as long as I could.   

[The Buddha]

Mark which cam was where and you wont have to time it on reassembly.
Cool.
Buddha.

[Roadstergal]

Oh, I should mention how it went...

I had the opportunity to try a few different methods.  By far the best was, similarly to what Dgyver said, turning the motor until the valves were all closed and making my own temporary timing marks.

To change the shims, I didn't have to take the cams all of the way off.  I found I could do the intake side by just doing what was mentioned above, taking off the caps, and rotating the cam forward enough to change the shims, then roll it back and reattach.  I had to loosen the tensioner a little to play the same trick with the exhaust cam.

By a nice coincidence, the shims for m'boy's CRF250X are the same as these Kibblewhite shims, so we have one stash for both bikes.  I wouldn't do this conversion for a street bike; it's just not worth the annoyance.

[the mole]

Just out of interest, what is the advantage of the conversion (for a race bike)?

[dgyver]

Less weight which means less valve float and higher rpms.