One cylinder Jackal

[paul in rochester]

After replacing the throttle bodies on my Jackal, she ran like new for a year and a half. Then she kept dropping the right cylinder.
Naturally, I did things backwards-swapped ignition parts side-to-side; nuthin'.
THEN I got the bright idea of looking at the plug...oily.
It took over a year and a half, but I finally got the time (and the gumption) to pull the right head. The process was actually straightforward (luckily, I had pulled the header pipes for something years ago, and had put some never seize on the studs, which was my biggest worry).
The exhaust valve looks like it's growing mushrooms. I don't have a dial indicator or anything, but the stem wobbles 1-2mm. The intake has barely perceptible movement. I'm guessing the worn guide is letting oil drip on down.
So, to a machine shop nearby that said they'd take a look. No one around here seems to have heard of k-lining, so it may be new guides.
If the valves don't seem worn, are they reusable? They seemed to clean up alright.
I'm going slow, so as not to mess things up. I've already lost the spring clip that holds the cylinder head temp connector to the sensor.
Oh, well.
I still have to pull the cylinder to look at the cylinder wall and the rings, though...since I'm this far anyway, and I can't see NOT replacing the base gasket since the load has bee releived.

[Mike Tashjian]

Usually a compression test will give you a good idea if things are going south.  Then a leak down test can verify leaks like a valve or rings. Since you have the engine partially apart this may be a good time to refresh both sides. A quality machine shop can measure your parts and give you a path forward. Then you can source needed parts to make things right.

[kingoffleece]

Absolutely.  You're half-way in already.  Do it all.

[PeteS]

The heads look fine and might even clean up with hand lapping. I sometimes I cut the mating surface on my lathe but its the stems that have to checked for wear or you will still leak oil even with new guides.

Pete

[moto-uno]

  I'm kinda on board with "PeteS" , I've seen hugely worse . Clean them off , lap them in and then find a couple of exhaust guide valve seals and
any smoking due to slightly looser guides pretty much goes away ( YES , you may ask me if I know this for a fact ) . Assuming no broken or seized
piston rings ! These are not high performance race engines  .

[Madtownguzzi]

So, to a machine shop nearby that said they'd take a look. No one around here seems to have heard of k-lining, so it may be new guides.

Knurling valve guides is the proper name to ask the machine shops for. I did knurl the valve guides on a 1960 VW bug in high school auto shop way back in 1969. I ground the valves and cut the seats also plus new rings. It ran great after the top end overhaul!

[moto-uno]

  You will want to be extra careful replacing guides on these cylinder heads , if there's any carbon left on the guides it'll take out material from the heads . If they haven't heard of K-lining the guides , they're from the dark ages , this has been common practice for ages . Send them out to a shop that does this if you feel the need to tighten the guide clearance !

[PeteS]

I think Paul has already found a shop for these but I know we have a few very competent places around here including Fast by Gast. State of the art equipment as well as a shop in Leroy. I have replaced guides. Its not that big of deal. Sand blast the head and heat it up. Guides typically come with an undersize ID  and can be had with an oversize OD. You cut and ream to fit the head and the valve stem.

https://www.youtube.com/watch?v=708hfR-i6aQ

Pete