6 replies to this topic

[whistler]

Had a strange one today. A friend has a 1275 metro engined mini which broke down. Long story but discovered today that the ignition had retarded itself about 10-15 degrees so that the engine would not start. Swapped complete ignition system to a spare I have and the same. Advanced as far as it would go until the distributor fouled the oil pipe and it runs. Changed back to original system and it runs at this new setting.

The timing chain is rattling its brains out and I was wondering if the chain has jumped a tooth and put the valve timing out. I did notice that about half of the rockers were way too tight. Going to set to tdc (7 & 8 rocking) in a couple of days and see if the pistons are actually at tdc.

 

A compression test showed between 65 and 70psi across all cylinders.

 

Rotor arm not 'wandering' on drive spigot.

Anyone come across this in a Mini engine.

A+ MG Metro engine with 65DM4 distributor.

The distributor had not moved from its previous set position when the breakdown occurred.

Edited by whistler, 28 March 2022 - 09:02 AM.

[Spider]

I doubt you'd be able to get the chain to hold together if it and the sprockets were worn enough to slip a tooth.

 

However, and as happened to me a short while back, the slot in the crank sprocket had widened and so wasn't staying put.

[whistler]

I doubt you'd be able to get the chain to hold together if it and the sprockets were worn enough to slip a tooth.

 

However, and as happened to me a short while back, the slot in the crank sprocket had widened and so wasn't staying put.

Thanks Chris, I had another thought overnight that if the engine has adjustable timing cam sprocket then maybe it has loosened. Going to have a TDC check tomorrow if the weather holds.

[whistler]

Stripped the timing chain cover off and found a very sad floppy chain and both gears with totally knackered teeth. Must be original chain, stamped AE and has a link in it.

[coopertaz]

if its that sloppy cam gear will have loads of free movement. with compression readings engine sounds about time for rebuild anyway

[whistler]

if its that sloppy cam gear will have loads of free movement. with compression readings engine sounds about time for rebuild anyway

I'm hoping that because the valve timing was out and the inlet (or maybe exhaust. I can't remember now) valve was partially open then max compression reading was before tdc.

We'll see when it's back together. 

I tried to attach a video to this post but error saying not allowed to upload this type of file.

Edited by whistler, 01 April 2022 - 02:03 PM.

[Spider]

I tried to attach a video to this post but error saying not allowed to upload this type of file.

 

This is whistler's video;-