Head Questions

[Calvin Blackmore]

Hell no. Clicking links someone else went to the trouble of posting is way overrated.


I wasn't having a sealing issue, I was just going to do it as a matter of course.
The way I knew one of my valves wasn't sealing was when, after a month of sitting, I pulled the valve cover, there wasn't any oil in one of the wells by the valve shim bucket. The rest had a uniform amount.

There had been oil standing there at one time, as evidenced by the residue. I figure that it's just a slow leaking oil seal.

OMG hahah
too funny thats is terrrific.

[Big T]

You don't want to contact area to be too wide - the service manual has a spec. If there are contact surface issues take the head and valves to a motorcycle machine shop and have them addressed properly.
Hope this helps and good luck.

And that spec is generally only a few millimeters. If your lap contact area is too wide, you have to start over by cutting a new seat.

[Steve]

I kinda like the method I used to lap the valves on my son's 850.

I took one of the allen-head bolts that I was replacing, found some rubber tubing that would slide over the head snugly, then chucked that in my battery-powered drill. I supported the head on the pull-out section of my table saw so I could reach both sides, then slid the valve into place and lifted it just a bit with my finger. Pressing the rubber hose on the face of the valve has just enough friction to spin it. I then slid the valve into place. By the time you push hard enough to spin the valve, you are pushing the valve too hard into the head, so you have to apply a little lifting pressure on the stem. Works real nice, takes longer to find the rubber hose for the friction drive than it does to spin eight valves.

By the way, I think the spec for the contact area is only ONE millimeter, not "a few millimeters". ONE millimeter is not very big.

.

[Suzuki_Don]

I kinda like the method I used to lap the valves on my son's 850.

I took one of the allen-head bolts that I was replacing, found some rubber tubing that would slide over the head snugly, then chucked that in my battery-powered drill. I supported the head on the pull-out section of my table saw so I could reach both sides, then slid the valve into place and lifted it just a bit with my finger. Pressing the rubber hose on the face of the valve has just enough friction to spin it. I then slid the valve into place. By the time you push hard enough to spin the valve, you are pushing the valve too hard into the head, so you have to apply a little lifting pressure on the stem. Works real nice, takes longer to find the rubber hose for the friction drive than it does to spin eight valves.

By the way, I think the spec for the contact area is only ONE millimeter, not "a few millimeters". ONE millimeter is not very big.

.

STEVE. Pics.

[doctorgonzo]

About to FINALLY start mine as well (rebuild). I parked it 3 weeks ago and a couple days ago started tearing it down. I will be back with MANY questions. My main curent concern is that the machine shop took too much off my "new" junkyard head to get it true.

[headsbikesmopars]

1 mm = .03937 inches