TOPIC:

Okay, so I removed the head today. Then I removed my #2 exhaust valve (the one whose clearance was under spec, and had the 200 shim). I had called a local mc mechanic to ask his opinion on what could be causing me to have low clearance with the thinnest shim installed.

He said it was more likely that my valve had worn down so that it was comming up further in the head seat, and less likely that the head seat was worn.

Looking at my exhaust valve, I'm not sure what to look for or measure to tell if it is the problem. I have a good micrometer, but what or where should I be measuring?

I measured the distance at the top of the stem from the notch to the top, and it measured 4.6mm. So if I had to grind it, I've got space to work with. But if the "bell" end of the valve is worn, I should just replace the valve, right? How can I tell?

Post edited by: Skyman, at: 2006/12/23 22:19

Another question. When I removed the head, and took a look at the piston tops and combustion chamber area, there was a lot of carbon buildup. Should I try to clean this up? What is the best way to do it?

Also, I noticed that on the piston tops, there are two small indentations on each piston that look like they were formed by the valve hitting the piston. Are they designed this way, or am I seeing valve damage to the pistons? (sorry if that is a dumb question--this is my first time inside an engine).

I have had the stem ground to recover clearance on my J. there is a spec in the menial which states that the minimum distance from collet groove to stem top should not be less than 4.2mm. Since the stem top must be ground square I would get a shop to do it. failing that its a new valve seat

Skyman wrote:

Another question. When I removed the head, and took a look at the piston tops and combustion chamber area, there was a lot of carbon buildup. Should I try to clean this up? What is the best way to do it?

Also, I noticed that on the piston tops, there are two small indentations on each piston that look like they were formed by the valve hitting the piston. Are they designed this way, or am I seeing valve damage to the pistons? (sorry if that is a dumb question--this is my first time inside an engine).

A lot of carbon is not so good, because there bring a lot of influence of valve steam und valve seat. If the carbon goes to the valve, they will not close perfect and finaly, you will destroy your piston. So you will have difference in your shims-meassuring.

You will have a bad compression. To see if the piston-rings are o.k. you have to do a compression-test by blowing air in the cylinder.

You will loose also the seal beetween cylinder and piston, so more oil will come in the combustion chamber and will produce more carbon. ....growing process.

It exists a lot of additive for cleaning the carbon, but in your case, I am not sure that this will bring your a benefit. To clean "manuell", you will use a wood-stick, so you can not destroy the bike-material.

I think you will have a lot of work and I wish you good luck.

Since there have been new posts to this original topic, I should give an update.

I have completely disassembled the head and cleaned everything up. My boss has a well-equipped personal shop where he also has a glass bead cabinet, which he let me use. My head and cylinder block now look brand new. Now I've got to figure out how to get my lower cases cleaned up so they match the top end. I'd rather not take them off the bike, but that might be the best way to clean them up.

My brother is an auto mechanic, and I went to his shop and saw that they had an old valve grinder in the back that hadn't been used in years. He said that they send all their valve work out now, so don't use it anymore. I figured out how to use the stem grinder, and so I took .2mm off all my valve stems to recover some clearance.

Grinding the valve seats looked much more complicated, and my brother had no idea how to use their machine to do it. I didn't want to screw it up, so I'm leaving it to the pros.

I called my local Kawi dealer and asked them if they could tell me where they have their machine shop work done--since they don't work on old bikes, I figured they wouldn't mind telling me. They gave me the name of the place and said they do a good job. They quoted me $70 to resurface the valves and seats, and another $24 to hone my cylinders (I'm putting in new piston rings too).

So, I've got new rings, top-end gasket set, valve seals, tach seal, cam chain guides and dampers and a Dymo-S ignition. I also picked up a box of 50 shims on E-Bay for $30. So as soon as I get my head and jugs back from the machine shop tomorrow, I think I'll finally be ready to start putting this puppy back together. I can't wait to get it running!

Post edited by: Skyman, at: 2007/01/15 14:56

Congratulations, You worked very hard and you made a very good and excelent job. I wish the same for me

Have fun with your bike and all time, as we wished for all bikers, a guardian angel.

Post edited by: Zinamia, at: 2007/01/15 15:08

Skyman wrote:

But I did a cold test, and the results were:
1: 145
2: 140
3: 125
4: 125

A little late, but I have a theory on this one, and it only works if the bike sat on its side stand. we all know that putting oil in the cylinders will bump compression, and the bike would be leaning with the #1 and #2 cylinders lower than the other two on its side stand, so oil from the cam area would have flowed down hill and more could have potentially leaked past the valve seals of #1 and #2 into the cylinders as it sat there, leading to higher compression.
my $0.02:)
Scott

77KZ650 wrote:

A little late, but I have a theory on this one, and it only works if the bike sat on its side stand. we all know that putting oil in the cylinders will bump compression, and the bike would be leaning with the #1 and #2 cylinders lower than the other two on its side stand, so oil from the cam area would have flowed down hill and more could have potentially leaked past the valve seals of #1 and #2 into the cylinders as it sat there, leading to higher compression.
my $0.02:)
Scott

Nice try. But I don't think that was the situation here. I had it up on the center stand, and it had been centered since I brought this baby home in November. I had also run the engine a few times early on, which should have burned out any leaked oil from the cams. But nice thinkin'.

Post edited by: Skyman, at: 2007/01/15 18:45

Skyman what do you suppose your cash out lay has been for all of this job?

pumps wrote:

Skyman what do you suppose your cash out lay has been for all of this job?

Ugh! You are sounding like my wife.

I've saved all my receipts, but I am refusing to add it all up until I'm done.

If I had to guess, I've probably put $700 in parts, tools, and machine work into this project so far. That includes a new side cover and a luggage rack and sissy bar and then all the engine and carb parts. I paid $800 for the bike. So in total, $1500-ish.

NOT trying to sound like your wife. Just trying to work up MY budget! For all that it sounds reasonable to me.