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· Registered
3,847 Posts
A few months ago I had to examine a CX that had run fine for

50 miles after the ( second hand) engine was installed then it suddenly locked up

just as he got home and right outside his garage door.

This was kind of lucky in that it didnt happen at speed.

One theory was the cam chain had snapped.

Anyway, motor dropped, back off and the cam chain etc was all fine

I found I could turn the motor one way then the other but at certain

positions near RH TDC, it stopped dead.

"Aha! Dropped valve" says I

Well it was and it wasnt

Some outer parts of the exhaust valve had broken off and by the looks of it

had been bouncing around a lttle bit before jamming between the

valve and piston.

I'm not saying this is your problem Mike and hope it isnt but

it has to be a possibilty

Its too serious not to drop the motor and examine anyway

Best case scenario may be a broken chain guide jamming the works

Good luck!

· Registered
3,847 Posts
I doubt it Mike

lets say it seized to the rotor

The starter would be driven by the engine at all times

but the engine itself would stiil spin normally when you put a socket on the front

take the plugs out an get a good strong torch and move each piston up and down

as much as you can and see if there's any sign of damage

If you remove the rear cover first before you touch the heads and you're lucky enough

to find something fixable, you wont have to disturb the heads

Its possible something broka and jammed between the chain and gears

lets hope its anything but dropping a valve as thats bad news!

· Registered
3,847 Posts
FOD eh?

tut tut !!

Well its a hell of a lot better than a dropped valve

I suggest you carefully check the affected parts

and cam chain for damage before reassembly

rear cover gasket:

I make my own so can you if your allowed to play with sharp things

and can source gasket paper about 20 by 16 inches ( 18X14 may do, its been a while)

and .8mm or 1/32" thick


Just remembered I have an aftermarlet one in the kitchen

and measured it.

Its .51mm ( 1/50th of an inch) so thinner than my home brew ones so you have a bit of latitude there.

Absolute minimum length and breadth is

16" high and 12" wide

· Registered
3,847 Posts

"picking it up looking somewhere to put. Ah ha Daddys engine. Drops it in"


"Soo Plausible"

It is isnt it?

My little uns used to 'feed' the video player with sweeties

and the stuff the little sods used to pack away

in every nook and cranny in the car....
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