yes, starter can do that!

[grapeview8n]

Got time to work on the siezed 8N 6V front mount again. Got the starter out and inspected, all good. Motor turns again (sigh of relief). I did find the ring gear teeth are ALMOST still there (see pics). But it wasn't just the one spot the starter hung up on. Looks like it's been that way a long time. Job for another lifetime.

I cleaned mating surfaces and reassembeld. Cranks fine again, but still barely runs. Long story short, 100psi #4, 50psi # 1 & 2, 0psi (yes zero) #3.
Suspecting stuck rings, I poured some Dexron in the front 3 holes and put the plugs back for the night. The saga continues, I'll update as I progress. Thanks for all your input, especially Bruce.
Oh, I also pulled the ditributor again and verified point gap and set timing, timing was way off.
My lesson, don't ever bypass those basics!

 

[Charles Krammin]

How did the rear starter bushing look? Something like that may cause wear on starter ring all the way around.
Charles Krammin SW MI

 

[Dean]

"0" psi. Not rings.

50 psi could be but likely not.

Look to head gasket and valves.

Do a dry/wet compression test.

Dean

 

[souNdguy]

I'm with dean.

0 psi is sounding like valves.

if the piston is in the jug and moving at all.. you will get more than 0 psi

 

[LEE DOTSON]

My old 8 n had set for years and #2 was 0 comp. soaked in fluid for a few days, but had to remove cover to get into valves to break it loose

 

[Royse]

Progress is always good!
Have you pulled the valve covers off the side and checked for
valve movement? You can spray them all down with ATF or your
favorite penetrating oil to help free them up too.

 

[Duner Wi]

I have a couple of times got stuck valves free by going thru spark plug hole.
On flat head Ford I made a tool from 1/4" rod that looked like an Allen wrench.
Don't pound,tap lightly. Have fun.

 

[grapeview8n]

Thanks guys. I will see what the soak does for me. The valve cover needs resealed anyway, so I may just go for it. I'm hoping the valve cover comes off with the manifold in place.
When I started with this tractor #4 only had 25psi. So I'm a believer in "soaking". My fingers are crossed so tight my arthritus is killing me.......

 

[ASEguy]

I think it's probably valves too. Those readings are exactly the reason to do a complete compression test every time. Gives you a better overall picture of the engine.

 

[Dollar Bill]

I'm hoping the valve cover comes off with the manifold in place.

They will come off without removing the manifold but access is a bit tight for getting to the valve assembly - Particularly on the two middle cylinders.

 

[Charner MS]

I"ve had the same problem on an tractor that has set up for a long time. I found the best solution is to pull the head (no big deal). You can see pistons and valves. Apply a healthy amount of penetrating oil - soak 24 hrs. Pull tractor in 3rd gear around about 15 minutes. I assure you this will either fix it or let you know what your problem(s) might be.

 

[souNdguy]

mix up some diesel and atf.. pull the plugs. fill the cyls up.. don't makker if some gets out an open valve. get as much in as you can..