fly wheel removal cam timing

[aprilia123]

have bought a 94 gs 500 motor with bad top end ( good bottom end).  then got a 99  good top end with bad crank .   put the 99 top on the 94 bottom end .  when I came to put the  exhaust cam in i  lined up   the R T   line on the crank and tryed to line up the 1 with small arrow  on the exhaust cam . It will not line up perfectly . Its allways  half a tooth off !!   . If I advance the cam a tooth the line is just bellow  the top machined face . If I go back one tooth its half a tooth above the case top edge . I thought well ....If the height is taller on the new cylinder relative to the crank centre line it will advance the cam . or if the head is shorter  it will retard the cam .  I then put the cams out the 94 motor in the 99  head .   the error is now half what it was !!  .   If I knew the cam specs IE    centre line degree  as in  112 for example I could slot the wheels and dial them in using a degree wheel .  did the motor change specs between 94 and 1999  ??   also how in the crap do you get the GD  flywheel off ,  i have a sliding hammer and a gas torch and it wont come off !!

[JamesG]

I don't think there were any drastic changes to cam timing, cylinder hight etc. between those years. You could be experiancing "factory tolerances" which are pretty tolerant on the GS. Could also be that your cam chain is stretched beyond serviceability. Know how many miles on the 94 engine? Do you have the manual for checking chain sloop?

Is the off-alignment before or after you tighten down the cam holders? I have rarely gotten them to line up properly when just hanging loose, but they will "straighten up" once seated and tension is put on the chain, even though the #1 exhaust cam will cause everything to straighten up at an angle.
Cam alignment is something of an art form on the GS. Do a search here and you will find that there has been plenty of gnashing of teeth over it. Might even be an advantage to have it "off" if you can figure out which way to change the timing will be beneficial to flow.

Slotting the cams on a GS is a PITA. Much grinding is required.

Flywheel:
Remove the nut off your rear wheel axle. Take said nut to a fastener shop (local hardware store probably won't have anything big enough). Get a hardened bolt about 5 inches long of the right size and pitch (20mm & 1 if I remember right). When you get it home cut off about an inch of the bottom of the bolt, careful not to mush the threads to much. You could buy 2 of them and mangle just the one, but I did it the hard way. Clean up the threads on both peices. Now with the headless stud, cut a slot across the top of the cut end and clean up the threads again so you can use a screwdriver to run it down into the crank. Thread the stud part down thru the flywheel part and all the way into the crankshaft so no part of it is still in the crank. Then screw the headed part in and torque it until the flywheel says uncle and pops off (Confession: This is the way I should have done it, but the way I actually did it was by sticking an 8mm bolt down the crankshaft until it bottomed out and then pressed against that. Not recomended as I mashed some of the crank threads).

DON'T attempt to just use your rear axle unless you want to buy a new one, and the OEM flywheel bolt is WAY to soft for this abuse.

Or... just buy the Suzuki specal generator puller bolt/tool thingy from Kowatools or take it to a shop where some punk will pop it off in about 10 seconds for $20.

You building a GS racebike? Total loss?

[Blueknyt]

Slotting the cams on a GS is a PITA. Much grinding is required.

Talk to Bob B. i got a set of slotted cams gears from him. thinking of scaring up some more of my cams and sending him the gears.

[sledge]

James?
Old Engineering proverb:  A little knowledge is a dangerous thing.

Another old Engineering proverb:  There is nothing more dangerous than someone who THINKS he knows what he is doing.

[sledge]

The flywheel is held on a tapered shaft, heat and levering will not free it. It must be drawn off as James correctly says (but does not do!), buying and using the correct tool is the easiest and safest way. Be careful with your knuckles when you tighten the bolt in the puller up, the flywheel will suddenly pop off the taper and might go flying, it wont  gradualy loosen in the way a nut and bolt does. When you do tighten the bolt in the puller up a sharp tap on the head in the direction of the crank axis will help free it. Dont hit it too hard, you may damage the crank thrust washers. You will need 2 spanners, 1 to stop the puller and flywheel turning, 1 to turn the bolt head.

[JamesG]

sigh...

see other post for response your prattle.

[Bob Broussard]

I loosen the flywheel bolt and back it out a few turns.
The I use a 3 jaw puller from Harbor Frieght tools.
I hook the tips of the puller on the edge of the flywheel with the center bolt on the head of the flywheel bolt.
I tighten it enough to put some tension on the flywheel.
The I take a hammer and give the puller bolt a good hit.
The flywheel will pop loose. If not just tighten the bolt for a little more tension and hit it again.
The only downside is the possibility of breaking the magnets.
If it's a racebike this doesn't matter. But if you don't overtighten the puller it should be fine. I've pulled quite a few without damage.

[starwalt]

I didn't like the idea of using an axle bolt either.  

I bought a cheap slide hammer from an import tool sale and cut new threads on the end to fit the flywheel/rotor. One pop and it was off.

You can see the photos of the fabrication HERE.

Cost effective? Not for single use. The die to cut the threads was almost $30, the slide hammer was less. On the other hand, I have super duper rotor puller! Hmmm. Maybe I should sell a few to pay for the materials? It would be easier to sell the rights to Bob B. and his team of fabrication gurus.  :lol:

[sledge]

Nice idea with the slide hammer, obviously it did the job, but I would be  reluctant to use this method. I am thinking about the crank, main and thrust  bearings and the amount of axial force they are being subjected to. The crank and bearings do not encounter large axial forces during running so its unlikely they will have been designed to accomodate them. The slide hammer as well as breaking the flywheel taper is shocking the crank out of its normal running position and hard up against the thrust bearing on the flywheel side. It may only be a few thou" but it could be enough to cause an effect. I do think this method could and I stress COULD cause some serious damage to the bottom end, particularly to the thrust bearings and at the very least it could potentialy shorten its lifespan.

[starwalt]

... I would be  reluctant....it could potentialy shorten its lifespan.

Point taken and valid except that Suzuki's very own removal tool is essentially the same gadget.  Go figure. :dunno:

When I said "one pop" it was a minor embellishment. It was more like a firm bump. I expected to have to get physical with it, but such was not the case. I believe the bike received more abuse at the hands of the previous owners/riders than I caused with the removal.  

A drawing of the Suzuki tool is in my OEM shop manual. As soon as I retrieve it from ECB (Have you read this Barry??) I will scan the pic and post it here if I have enough webspace.

[sledge]

I did say could damage, not would damage, it just seems a risky way of doing it to me and it goes against good Engineering practise when a screw type puller is just as effective and presents far less risk of damage. I have seen a lot of expensive parts damaged by brute force and ignorance over the years and find it pays to always step back, consider possible options and outcomes and just be cautious about the whole thing. I dont doubt what you say about your tool and method and If Suzuki reccomend it, it must be safe to do it in the manner you describe.