Ignition coils wired improperly? One cylinder not firing

[draser]

For valves and seats sealing surfaces I'd just do a quick lapping by hand, not much needed as we know the 3 cylinders were already good. No reason to brush on that side of valves.

[Sterminare]

All the valve/sets are out now. I did find one more spring that had a pretty significant rust spot on it, I wiped off the rust and found a pretty nasty looking crater: https://imgur.com/a/5KhOw27 so I wonder how much longer this one would've lasted before shearing

Took some pictures of the cylinder bores. Theres some minor vertical streaks that I cant catch with my fingernail. Its tough to see but I think I do see horizontal/cross hatching. https://imgur.com/a/e6x8RKU

I ended up cleaning the valve seats with carb cleaner and *plastic* brush wheel in my dremel, that got maybe 80% of the carbon off, then I picked off the rest very carefully with an aluminum pick that didn't leave scratches on the valveseat. They turned out pretty good. Valves and seats are looking quite clean I just have to scrub the pistons still.

[Pete in PA]

That cylinder wear looks like more than 5k miles to me.🤷  But Ive never done one at 5k miles.

You can do one more check before reassembly.
You can check the big end rod bearings by rotating the engine so the piston is going down then tap on the piston top with a wood rod. No movement allowed.

[mollusc]

Agreed.  I call BS on that being a 5k mile engine, unless it was run without oil.

[draser]

Can you post a pic of a valve sealing surface and a seat, closeup?

[Sterminare]

Can you post a pic of a valve sealing surface and a seat, closeup?

https://imgur.com/a/xEnaABG

Here are some closeups of the valve seats and an intake/exhaust pair

Just occupying myself while waiting for parts coming Wednesday. Painting the head, valve cover, other misc parts around the bike

[draser]

Yeah.. seats look good, some are very narrow (2mm??) looks like you have a good head. Given the low carbon deposits, seat/valve condition and the 175psi compression (hope you can replicate upon reassembly) I'd say you have a good head with a lot of life left.
Theoretically, if you'd use a black marker to black out the valve sealing surface, then insert the valve and spin several times pushing against the seat, if the mark left on the valve is about center on the valve sealing surface that's how the engine left factory. Or you'd see that after a short lapping.
As the seat wears out, the valves sink into the seat and the sealing "ring" on the valve moves towards the top and the seat width grows. That's how you tell an old head.

[Sterminare]

I was debating valve lapping, I was thinking they looked decent enough and made good compression and was worried about making it worse rather than better. But particularly the exhaust valves looked a little worse for wear, so I gave all the valves a light grind. They all look nice and wide I think. https://imgur.com/a/E0PeDSk

Cleaned everything thoroughly. Ruined my fresh paint job in the process, guess it wasn't fully cured even after 2 days.. oops. I'm more interested in getting it running well than looking good at the moment so that's something I'll fix another time.

Head is reinstalled on the bike, new head gasket and orings/crush washers everywhere as I go. Hoping to be able to at least check compression tomorrow if not get to fire it up.

[Pete in PA]

Great progress!  Looking forward to start up!

[Sterminare]

https://imgur.com/a/mEQLZMZ

Engine is complete! Best part: no more orange silicone everywhere (just don't look at the clutch cover, or the oil pan, or...)

When I opened up the valve cover I noticed the exhaust cam was advanced a tooth or 2. I made very sure that I have it timed correctly now. I hope I did it right and I hope I bled the tappets right. Everything went pretty smooth considering I've never done anything like this before...

Engine makes "engine noises" i.e. compression while turning over by hand during timing process. So that's a good sign.

Tomorrow morning I'll do a compression test and see what happens. Fingers crossed if it's good,  I'll hang the exhaust, replace the oil cooler, fill the oil back up and fire it up.

[Pete in PA]

Doing this outside, wow.  Deffinately on a time constraint.
Where are you located?