Just been on a fairly long drive. I now realise there are two more things I really need to do.
Clutch. It's not disengaging properly. I assume the best course of action is replacement as the engine will need to come out for a proper diagnoses? What sort of clutch should I use, it's a 3.8 MOD Moss.

Carbs. After driving at motorway speed the revs stay at about 1500rpm. If I give a few blips it drops to the correct idle speed. I am assuming the butterfly shaft is sticking/bent or the bushes are worn out. Is this a fairly straight forward replacement?

 

if the carb problem can consistently be rectified by blipping the throttle pedal, it could be caused by friction or lack of spring force anywhere between the pedal and the butterflies.

but there have been threads and posts noting similar problems that have never been resolved with anything approaching consensus.

from first hand experience, my '67 will usually idle at 900rpm but, on occasion will prefer to remain at 1200 regardless of what i do. i've decided to live with it. *shrug*

actual RPM should probably be measured, if that's important, with a modern timing gun's inductive pick-up. they are much more accurate than a 60 year-old tach.

 

If the clutch is not disengaging, it's not due to wear. Some clutches have a self adjustment that can go wrong and some have some adjustment near the slave cylinder. It's also possible to have problems with the hydraulic cylinders, though in my experience that usually results in the clutch not disengaging at all. Most likely, you can resolve this without pulling the engine.

For the idle speed, first check that all the return springs on the carbs are present.

 

The gears are just a bit difficult to select. 2nd requires a double declutch if I want to be sure of a smooth change. I know a moss is not the smoothest but this is not right. I can just feel through the gear stick like I am not pushing the clutch pedal all the way in.

 

When I wrote not due to wear that meant the friction plate - it could be the release bearing which would be an engine out. Unfortunately, the standard release bearing can be a little fragile if harshly treated.

To be sure the clutch is dragging, if the car is on level ground, does the car move forward when first gear is engaged and the clutch held fully depressed and handbrake released?

 

No it doesn’t move forward.

 

It could be a matter of getting used to the slow synchromesh of the Moss box. I know that many suggest double declutching, but some careful speed matching and adjusting to the nature of the gearbox generally worked for me.

 

i've got a fully synchromesh '67 mk2 so no problems with shifting, but i also own a '53 mgtd and shifting without grinding demands a slight pause (sub-second yet deliberate) in neutral with a bit of pressure into the next higher gear during the pause before it will shift smoothly on upshifts. otherwise i will always get grinding. but eventually i developed the habit of upshifting slowly (i.e. waiting for sychros to do their work) and rarely have any problem anymore. i avoid downshifting as much as possible, and when forced to i rev match using a bit of pedal blip. usually two blips.

the reasons are that on upshift the engine is running at too high an rpm for the next gear and needs to drop down a bit, hence the pause in neutral, to match properly, especially so with the primitive sychros of the era. and on downshift the engine is running to slow to properly match the next lower gear and so, while in neutral, the rpms need to be boosted a bit, and so, the blip.

if i'm telling you something you already know, and i have no way of knowing whether i am or not, please disregard.

 

Just about every Mk1 and Mk2 I have owned had sticking throttles which would not drop back to idle.
The solution is to go after the throttle linkages starting at the accelerator pedal and lubricating every moving part. The cross shaft from the pedal to the linkage arm is a particular offender
In addition, check that the correct springs are fitted to the system. It's amazing how many springs have been found to be missing.

 

Thanks everyone. I think the sticky throttle and "difficult" gears changes might be related at the revs stay at around 1500 when I release the throttle unless I blip. I will be checking all the linkages and springs today.

I took a look at my clutch and the slave cylinder has a spring attached so I assume this is the "self adjusting" one? It looks like I can still adjust it, have to take a better look today.

 

Frequently the issue is caused by a worn, rusted, un-lubricated or fouled splined shaft.

 

Also listen to Bill.