DG1900 locks after approx 260 degrees revolution

[itchyfeet]

I shoupd add If valve is not stuck down( easy to see with covers off) then unlikely a head
could of course be clutch or even gearbox and you may take heads off for no reason.

[maxstu]

Inlet valve no 4 cylinder cupped. And adjuster screw end damaged

[maxstu]

Damage to tappet adjluster. Second from right. 1985 engine. 9 or 10 mm size?

Lastly l have a working 2.1 on carb spare engine. Is there much difference in plumbing? I know post 1985 adopted the more familiar cooling system. Are they interchangeable?

[itchyfeet]

is the valve the same height?
will it turn now the pushrods are out

[maxstu]

In this condition l can get nearly 360 degrees on crank pulley wheel. I kept my finger on end of culprit valve during clockwise and anti-clockwise turn. It did not move whatsoever.

[maxstu]

No valve movement noticeable from any of left valve train. Culprit valve is in a bit...but its damaged.

[itchyfeet]

worn valve is from a duff tappet does not mean thats the issue

have you taken plugs out and sign of anything odd?

[maxstu]

Yes plugs out. Good colour on all.
Am close to dropping engine! Any ideas where to go from here

[itchyfeet]

USB endoscope in plug hole or into sump may tell you something
get them for under 10 quid on ebay

this

[maxstu]

Ive just placed the blunt end of a kebab stick down spark plug hole of culprit barrel until it hit top of piston. As l rotate crank pulley wheel The piston will come to TDC and pass back down again. Oh dear

[maxstu]

USB endoscope in plug hole or into sump may tell you something
get them for under 10 quid on ebay

this

This it is for now. So drop oil and give it a damn painful colonoscopy with USB endo

[itchyfeet]

in through the pllug holes mainly if you attach a piece of wire or string to the end you should be able to pull the end around so you are looking at all angles and even back at the head.

unless you know what the inside of the crankcase looks like you might struggle to see anything unusual.

[maxstu]

Okay and thanks. What am l looking for? Also do you know if 2.1 on carb will swap out with pre 85 engine. I know coolant system is completely different. But is the main engine identical?

[itchyfeet]

looking for foreign objects, bits broken off piston, evidence of valve hitting piston

yes 2.1 will fit with 2e3 but oil cooler needs some plumbing

[maxstu]

looking for foreign objects, bits broken off piston, evidence of valve hitting piston

yes 2.1 will fit with 2e3 but oil cooler needs some plumbing

Okay. But l was thinking on the cooling side there would be difficulties match pre and post DG's