Valve clearance spec?

I am about to reassemble my '82 seca, but while I have the tank off, I figured I'd check the valve clearance.
I assume you need to measure between the lobe and the "lifter" while at TDC on each cylinder.
I don't have a manual, and have not recieved the XJCD yet, so I am hoping someone here knows the clearance spec. off the top of their head.
Torque specs and tightening pattern on the cams would be great as well.
Also is there anything I should watch out for when doing this?
Any help is greatly appreciated.

Nachoman

 

Check each valve clearance with the cam lobe at 180 degrees from the cam bucket that your checking.
Check the clearance with the engine cold.

Clearances on xj650j engines
inlet 0.16 to 0.20 mm
exhaust 0.16 to 0.20 mm

All other engines
inlet 0.11 to 0.15 mm
exhaust 0.16 to 0.20 mm

If they are out of spec you need to know what shim is in that position and look up on a chart to find what shim needs to be installed.

Knowing which shim is currently in each postion really helps in calculations.

You also need a tool to hold the shim bucket down while removing the shim in question. I made one out of a chunk of angle iron and it worked very well.

When I assembled my "box of parts" I recorded each shim and checked the clearances. Only had one in the correct place, could move the others around, but needed to buy 4 other shim sizes.

The cam cap bolts should be torqued in two stages with the final torque to be 7.2 ft-lb. No indication on tightening sequence, manual just says tighten evenly or damage to cylinder head, cam caps, and cam will result. Not much help in that comment!

 

Need to know if it is a 650 or 750. They are different. For the 750 the specs are <Exhaust: .16 to .20mm.> <Intake: .11 to .15mm.> Rotate the engine by way of a 19mm wrench on the left side crank end accessed by removing the left point cover. Rotate until the cam lobe is directly opposite the shim and shim bucket. Insert feeler gauge between the cam and shim.

On the cam torque specs they are 7.2ftlbs for the cam cap bolts and 14.3 for the sprocket bolts. First install the forward cam chain guide if it was removed. Can't get it in after the cams are in.
Sequence is to align the timing marks on the cams with the timing marks on the cam journal. Then gradually tighten by about 1/2 turn at a time until the cam is seated. Don't forget to slip the cam sprockets on before inserting the cams. The cam seats unevenly due to it's opening some valves and not others. The idea is to keep the cam going down evenly until the valves springs are compressed and then torque to spec. I torqued to half and then full. Once both camshafts are in I then attach the rear sprocket with the chain on it using "one" bolt hand tight. Align the marks and slip the other sprocket and chain on. By installing the cams first and then the sprockets with the chain you will have enough slack to get the chain on. Once on and the timing marks are checked then rotate the engine through 2 revolutions with the afore mentioned 19mm wrench(counter clockwise) and check the timing marks again. If they aren't spot on then adjust the chain to the misaligned sprocket and cam. The cam can be rotated with a. (22mm I think) wrench to align the marks while moving the chain links to match the timing marks. 2 more revolutions and check again. If all is well then install the remaining sprockets bolts and now torque them to spec while using a 19mm wrench to hold the engine and cams from rotating due to the torque wrench force.
There was quite some discussion on another list about the correct torque method for the cam cap bolts. I would dry them of any oil and then torque. A wipe with a shop rag should do it.

 

One other hint that I didn't do but thought of afterward. While the cams are out the shims can be removed and there size and location recorded on paper. Then when measuring the clearances you already know which shim is in that valve bucket. Calculate your needed shim with shim chart and order what you need. Then update the replaced shims.
Still mad at myself for not doing this!

 

Maybe a little heads up
I did the shim thing and needed to buy three shims after shuffling the others, and the dealer said two weeks to get some(5.99 ea.) ...Went to small engine guy around the corner and he had them in a drawer and was willing to exchange shim for shim. sometimes I can't see the forest...

Jeff

 

Here's a picture of my homemade shim tool, made from a chunk of angle iron.
You will need something to hold down the bucket while rotating the cam lobe out of the way. You will also need a small screwdriver and a magnet to get the shim out.
As BlueMaxim stated there is a chart for the intake valve setting and one for the exhaust setting, which will take the brain power out of the calculations for what shim is required to get the correct valve clearance.
The shims are 29mm dia by thickness ranging from 2.00 to 3.20mm in 0.05mm increments.
I picked-up 4 replacement shims from my local Yamaha shop for $2.00 each (cdn $$ yet ).