I had to replace my base gasket which meant pulling the top end off the bike.  I'm currently putting everything back together and I'm to the point of re-setting the engine timing.  

My question is when I rotate the engine to the "RT" mark on the generator coil which piston needs to be up and which one needs to be down?  I noticed that when I was checking my valve clearances I had to rotate the crank twice to get the camshafts to rotate once.  So if I set up the cam chain and camshafts on the wrong rotation I'm thinkin' the thing will never start.

Does this make any sense . . . . . It is 2:45am and all!  

Thanks!  

ok, slow down and take things one step at a time or your going to mess it up, set the crank with the right piston up (so it whould be firing)  The timing plate only goes on one way, and the ignition advancer goes on one way, so put all that together. and you already got that far right?  ok the next thing is to get the cyl back on and the head on,   by the way you a manual?

just reread your post, yeah everything is set to the right cyl.  yeah the cams only go around half as much as the crank cause it is a 4 stroke motor and they are only working half the time. in about 5 minutes blueknyt will chime in here as to the redneck way to do this in 15 minutes, so you'll just have to wait for him

See Bob Broussard's instructions in the old Engine timing thread.  (His 2nd post.)

(queing up banjo and bass fiddle)

loookee here sssssoney



ok, aslong as your rotor is mounted correctly and your timing mark is set to RT, then dont worry about which piston is up. the left is number one but for some odd reason they set the cam timing to the right (go figure) i went by normal thinking the first time and had my cams backwards, it was sucking in the exhaust ports and puffin out the intakes.


RT | to the left timing triger just like the book says, then set your exhaust cam with notch facing left even with the top of the head. (make sure you have all the slack out of the chain and front chain guide is in first) tighten down your cam caps till about 2 fingers snug (nice and easy) the cam is going to want to turn on you cuz its pushing on a valve try not to let it. set the intake in place notch facing to the exhaust cam. back to exhaust cam you will see number 1 pointing to the front edge of head, a number 2 pointing about straight up to a pin on the chain, count 18 pins from there to the intake cam and you should see a number 3 pointing to that 18th pin. if there is no slack, exhust cam didnt move, pin 1 on Mark #2 and pin 18 on Mark #3, Both cam notches are faceing eacherother nice an perfect all while  the timing mark RT is on the left hand pickup, stick the chain tensioner in and make sure all cam caps are torqued to proper tension, and you did it.   it sounds alot more complicated then it is.

Was going to post a seperate topic, but this is so close to what I need, I figured I would add it here. I'm at teh same point but my bike has a V&H advancer on it. I didn't know that till I cleaned the RUST off of it! Anyway, I THINK I had it set where the RT mark should be on the stock advancer. And if I remember right the left piston was up. Please help a GS500 newbie out! Got to get this thing put back together.

Do it like Blueknyt said and you can't go wrong. Be sure to count the chain pins. If they come out to anything other than 18 you know you're off a little. So here's the summary...

1.  RT mark
2. Slots on cams facing inward.
3. 18 camchain pins between dots on cam sprockets.

And if you're uncertain it's right absolutely don't turn the engine over. Sorry Zilla, we posted at the same time. This is for the stock setup so I'm not sure about the modified advancer.  

Derek

has any oneevery triedadvancing or retarding the cam timing?  this is common practice on high perfromance car engines.  advance moves max hp/torq down in the rpm range for more low end power,  while retard moves it up in the rpm range.  on car engines its usually done in 3 degree increments untill you get what you want.  just wonder if anyone has tried??

You guys are awesome!!!

I know the rotor is mounted correctly because I didn't tinker with anything lower than the base gasket.  I should've marked my cam chain like the Haynes manual says to do, but I knew if I could just find out which piston had to up and which one had to be down I could get it right.

Thanks again - you're the coolest!   :mrgreen:

   

marking the cam chain isnt always accurate as you will get slack in it and it could shift a few teeth on the crank, thats why i said make sure all slack is out and front guide is in place when you set the exhaust cam. i've just read Bob B's instructions and the idea of leaving off the one exhaust cam cap setting up the timeing with chain tensioner and rotating the engine backwords oh so gently till the cam lays flat, tightening down the caps then rotating the engine gently the other way to make sure all marks are lined up sounds alot easyer.

I set the timing with the nub of the rotor pointing straight up. In this position, the cams are off the valves and the caps can be tightened easily. Not sure if this would be the same 12:00 position with stock cams. I always roll the motor forward to double check every thing. Bent valves suck. Done this so many times, I probably could do this blind folded now.

I am in the process of ensuring my cams are set correctly as I have replaced a right exhaust shim.
My confusion is that I can see the marker #3 (on intake cam) and marker #2 (on exhaust cam). They are pointing upwards, and I also have 18 pins between them... but I dont see any notches on the gear part and my rotor marks are not lined up, is this a problem???

The notches are not on the gears, they are at the end of the camshaft. The ignition rotor should line up at the R-T mark in this position.

To replace shims you shouldn't have needed to dismantle anything camshaft wise. Did you do that anayway? If so, take them out again, bring the ignition rotor to the R-T position first, then[/ i] install the camshaft.

Turning the engine over with cams not synchronized properly has the potential to damage your valves.

Here is Bob Broussard's quotes from the mentioned link.

Quote


The pickup with the black/white wire is the Right cylinder.
Green/white is left.
It sends a pulse each time the rotor passes the pickup.

Quote


First step is to line up the TDC mark on the rotor with the forward facing pickup. That will put the right side piston at TDC.
The exhaust cam will stick up on the left side. Just leave the cam bearing caps off for now on the exhaust. Just finger tighten the intake side after you line up the marks. Slowly turn the crank backwards until the exhuast cam sits down in the head. Finger tighten the bearing caps. Then release the chain tensioner. Rotate the crank forward until the TDC mark lines up with the pickup. Check the alignment of the cam timing marks making sure the rotor is lined up at TDC.
If the marks are off, then move the crank backwards to the point where no valves are being opened. This should be the same point where the exhaust cam sat in the head. Remove tension on the cam chain and re-adjust the cams as needed. Put tension on the cam chain and rotate forward to TDC.
Putting tension on the cam chain is critical. The cams timing is moved when you apply tension.
You should not rotate the crank completely until the timing is lined up correctly. It could bend a valve 

Quote


The valves can be straightened.
You need to put them in the lathe chuck and use a dial indicator to see where to adjust them. Then use a soft mallet to wack the head to tweak it straight.
Once they're as close to straight as you can get them, have a shop grind the seat area. Then you should be able to lap them in with lapping paste.
You might be able to do it by just lapping them.

What grind cams are you using? The ones I use require some mods to the head to clear the lobes, and different spring/bucket setup.
I'm going to do something similar to what you did. I have 1mm over stock pistons. I'll mill the head and see what I can get out of the stock components.
I have 34mm carbs off an 03GS from Canada I'm gonna use.

Quote


I'm running 384X4 cams (.438 lift). It required removing some material from the head where the buckets sit. The lobes will hit the front/back edge of the bucket area. I converted to shim under bucket.
Check with Kibblewhite Precision Machining (650-359-4704). Let me know if you have any trouble dealing with them. They are great folks, but have changed their policy on dealing with individuals (been burned too many times  ) I'm grandfathered in so I can help you out.
They will put together a kit with springs , buckets, Titanium retainers, collets.
I think it was around $150.00.
You will need to use Kawasaki 13mm shims to set valve clearence.
Much lighter than stock setup and won't spit a shim at higher rpm.

Now the way you describe the bent valves, sounds like they got bent by the intake valves contacting the exhaust valves. I had problems with that because someone degreed the cams wrong. The intakes where closing as the exhaust opened and they clipped each other.. Didn't bend the intake valves but did start to warp the edge. They get hot and soft and tweak easily. Also the bind on the valve stem kept breaking valve guides right where the clip fits in the groove. Which reminds me. With the cams I run I had to change to shorter valve guides or the retainers would mash the seals. You probably have the max lift to use the stock guides.


Put some clay on a piston and put the head on. Then after the cams are set up. just rotate the crank slowly by hand. Remove the head and cut some of the clay away so you can measure the thickness of the clay where the valves are. I would check with Megacycle on minimum clearence, I can't remember off hand.

I have JE pistons with massive domes to raise compression, so I haven't dealt with milling the head.  How much did the mill off the head?
I can cut some extra clearence in the pistons if needed, since I have the equipment. My investments are finally paying off 

 ok thanks