AN650-Valve Tappet Inspection with Pictures

[placervillebob]

Thanks TechArtGuy.
If I want to change shims - how much more difficult is it from this point? I only need to remove the Exhaust cam. Would that require the special tool - Chain tensioner lock tool? After I remove the camshaft journal holder (for the exhaust side) can I simply slip the cam/gear assy out? Will there be problems with the timing chain upon re-installation with taking out only the exhaust side? I have CD service manual but it is rather sketchy as to instructions.
Thanks for your help.
Placervillebob

[Buffalo]

You will have to release the tension on the cam chain tensioner to be able to remove and reinstall the cams.

[Buffalo]

Getting the cams out and back in once you get slack in the chain is not problem. Just be sure you have the pistons at TDC with the cam alignment marks oriented correctly before you take them out. It's not a difficult job you just have to pay attention to the details for alignment. You remove the cam journal holder and lift the cam out angling it slightly to get the sprocket out of the chain. You don't have to take both cams out, you can just remove the exhaust if that is the only one that needs adjustment. Again look carefully at the alignment marks on the end of the cam before you remove it and put it back exactly the same way.

[placervillebob]

Thanks for the instructions - I think I understand but have a couple of more questions.
Buffalo - you mentioned about releasing the tension on the cam chain tensioner. Where is that and how is it done?
I planned to simply lift up the end of the cam opposite the gear to remove the shims - hopefully not even disengaging the teeth from the chain. Is this possible? Also, is it easiest to remove the shims using a magnet? Lastly, in my case I need to remove .002 of thickness from a couple of the shims. If I use a surface grinder to do that would that work (as opposed to replacing with thinner shims)?
I really appreciate the help. I hate to put this back together when I am this close to bringing everything back to nominal.
Thanks again
placervillebob

[TechArtGuy]

The tensioner is on the left side looking at the head from the front of the bike. It has a spring on the bottom of it to the left of the cam sprockets. Releasing the tensioner can be done in two ways, suzuki has a "special tool" for locking the pin which is nothing more than a piece of wire the right size. A drill bit or anything else sufficiently size will work. The other method is using a deep well socket to hold the pin up and spring up and a quickclamp to hold the socket in place. To get release the pin you'll see a small block above the spring on the tensioner. Push the block on it's lower edge to release the spring/pin then push up on the the spring/pin. At this point you can either use the deep well to hold it up or said drill bit/wire to lock it in.

[Buffalo]

Thanks for the instructions - I think I understand but have a couple of more questions.
Buffalo - you mentioned about releasing the tension on the cam chain tensioner. Where is that and how is it done?
I planned to simply lift up the end of the cam opposite the gear to remove the shims - hopefully not even disengaging the teeth from the chain. Is this possible? Also, is it easiest to remove the shims using a magnet? Lastly, in my case I need to remove .002 of thickness from a couple of the shims. If I use a surface grinder to do that would that work (as opposed to replacing with thinner shims)?
I really appreciate the help. I hate to put this back together when I am this close to bringing everything back to nominal.
Thanks again
placervillebob

I don't think you can lift it high enough. You don't just remove the shims. You have to remove the tappets that cover them first. The tappets are what the cams push against to open the valves. The shims are under them and separate them from the top of the valve. A magnet is helpful to pull the tappets and shims up out of the head.

To release the tension on the cam you push in a button and compress the spring. I've got the tensioner out of my bike right now so I shot a picture. Look at it and right at the top of the spring is a square button in a recess. Press that button in and the rod inside the spring can be pushed up compressing the spring. Once the spring is compressed the special tool goes in a hole right above the button to keep the rod from going back out.

In this picture I have compressed the spring up and pushed an ice pick into the hole to keep it compressed. The adjuster is laying over on it's side relative to the first picture with the ice pick sticking in where the button can be seen in the first picture.

I don't know about the wisdom of trying to grind .002 off the shims. Might work and it might not. The proper way to do it is once you have the shim out, read the thickness on it and buy one that is .002 thinner. If you do decide to try it, I would suggest grinding off the side with the size on it. Otherwise someone in the future who did not know what you had done would be confused about the size of the shim. The down side of that is that only you would know what the size of the shim in the head is as it would have no size imprinted on it.

[placervillebob]

Buffalo - I just re-read your answer where you say to have the pistons at TDC and the cam alignment marks oriented correctly. Is that #1 or #2 piston at TDC (both can't be at TDC or can they) and using the original posters photos (first photo of step 18) how should the marks be oriented. Should the "A" be as shown or should I be aligning to something else.
Sorry for being so dense but I hate to screw this up.
Thanks for your patience.
placervillebob

[Buffalo]

Actually they both come to TDC at the same time but one is on the power stroke and one is on the exhaust stroke. The pistons rise and fall together. To tell you the truth, I don't remember for sure which one is suppose to be on the power stroke and my manual is on loan right now so I can't look it up. I do remember that I had to align the cams to the same position as the service manual specifies for checking the first set of valve clearances but I don't remember if that was for cylinder 1 or 2.

[placervillebob]

Thank you both (Buffalo & TechArtGuy) for hanging in there with me.
I set the marks on the gears as if I were checking the clearances for cylinder #2. Then I marked the links of the chain with a felt pen and am glad I did because when I released the tension, the chain popped and jumped 1 tooth on the Inlet sprocket. Had I not marked it I would have been unsure as to the timing. Thanks for the pictures and descriptions of how to release the chain tension, they helped a lot. I had no idea the shims were so small in diameter. What keeps them in position, centered in the cup when you re-install them? TechArtGuy mentioned moly grease for re-assembly? Is this compatible with engine oil? As practice I placed one in the bottom of the cup and held it in place with a magnet during re-installation, but need to know how it should be done when I get the correct sizes.
I just want to verify the torque on the Cam Journal Holder Bolts – 7.4 lb/ft. The break-away torque was significant but may have been from never being taken apart from new.
Thanks again for you help
placervillebob

[Buffalo]

They just sit in depressions in the top of the spring retainers. I put them in place in the depressions then place the tappets down over them. You can buy bottles of reassembly lube to coat the bearing surfaces with before reassembly so they won't be dry when you first start the engine.

Edited to add, the 7.4 sounds right but I again I don't have my manual right now so I can't look it up.

[TechArtGuy]

Buffalo and placervillebob,

I got the torque value out of my own service manual when I made the post so should be correct lest my reading ability deceives me . My larger torque wrench didn't go that low but the accuracy of the torque also declines on the farther edges of the scale. I did have an inch pound torque wrench so I just converted the value from ft/lb to in/lb by multiplying by 12. Same conversion for the other way just divide by 12. But, they did take a little force to break loose but putting them back on you hardly feel like you're tightening them down at all at such a low torque.

[placervillebob]

SUCCESS – My 650 Scoot is back together with new shims that provide nominal clearance and all is well. It runs great and I have to thank both Buffalo and TecArtGuy for the help they provided – this forum is great. I am convinced the local shop would not have provided me the attention to detail this scoot saw for this service (their comment was – “WOW we have never seen a Burgman before but bring it in and we will take care of you”). If one of us needed to learn, better it be me.
Thanks again for your help and I will be using this forum a lot in the future.
placervillebob

[JohnK]

Congrats on joining the DIY club. You learned more about your bike and saved $60-80 per hour. If they have never even seen one then they know even less about working on it then you do.

[ASpring6]

So I have been in the process of replacing the casting plugs in my 2003 650. Not thinking while disassembly, i didn’t mark the chain or cams for realignment. What I was planning on doing was turning the bolt http://burgmanusa.com/gallery/allwalk/album09/650_valve_21.jpg.html?g2_imageViewsIndex=1 to bring the pistons to TDC. But I'm not sure if this would be TDC because I have no idea where the pistons really are, so my plan is to align the markings on the bolt then take out a sparkplug and see if the pistons are really at the top of the cylinders.

I'm kind of lost, but I'm thinking this is my best plan of action. If you could, please let me know if I'm looking too far into this or if I'm on track..

This forum and everyone has been a great wealth of knowledge while I’ve been working on this project..

[Buffalo]

If you turn it until the mark is aligned, the pistons should be at TDC. If you want to be absolutely sure, you can put a screwdriver or dowel or something similar down in the sparkplug hole then slowly turn the crank by hand and feel the piston rise. It should hit the highest point when the mark aligns then start to fall back down.

You don't really need to mark the cam chain. I didn't mark mine. You just have to follow the instructions in the manual and count the rollers between the marks on the cam sprockets. You align one roller with the 2 mark on the exhaust cam then count over 15 rollers and align that roller with the 3 mark on the intake cam making sure you have both cams oriented correctly in the heads.

[ASpring6]

Thanks! Planning on doing this later today and measuring valve clearances. Will keep updating progress.