Have hit a snag changing tha cambelt on my 93 NA, I have undone the 4 10mm bolts and removed the washer and the crank pulley but the dished cambelt guide plate behind will not budge. The manual I am using says you don’t have to remove the 21mm bolt from the centre of the crank just remove the pulley and plate but the plate has a dowel to locate the pulley and is threaded to take the pulley retaining bolts.Do I just need a 2 armed puller to pull the plate off or is it held by the crank centre bolt
pretty sure you have to remove the 21mm , the 10mm are to avoid a friction only contact between pulley and crank i believe.
The way i saw it last month (1.8 ) was the pulley is used as a washer to hold the bottom timing gear on if you get what i mean.
Theres a good thread on here on how to do the whole job.
Depends on if it is a 1.6 or 1.8?
1.6
As it is a 1.6 you do not need to remove the toothed bottom drive for the cambelt to replace the cambelt but on a 1.8 you do.
If you are replacing the front crank seal then you do need to remove the toothed drive, lots of Plusgas (better than WD40) bit of gentle tapping and a small amount of leverage and it should slide off the crank and its woodruff key, you will need to undo the crankshaft 21mm headed bolt, if you do not have access to the special tool you can thread a length of cord down into No1 cylinder when it is just past TDC then undo the crank bolt, the cord will lock the piston crown against the inside of the head (without damage) but you will need a 6 point 21mm socket and a 600mm breaker bar to get it shifted.
Dr Eunos 
Just to add further, if you are replacing the cambelt only (without doing the waterpump too) you can simply cut the existing belt in half lengthwise using a stanley knife, remove the front-half of the severed belt and slip your new belt half on before cutting the remaining old belt and sliding the new one into place fully.
That way it is impossible to get the cam timing wrong 
Dr Eunos
The problem is the dished cambelt guide that’s in front of the toothed sprocket so there’s no room to remove the cambelt, it looks as though it should slide off the end of the cranshaft without removing the centre bolt but won’t shift, have srayed plenty of WD40 as theres a bit of surface rust
Tap it a bit with a soft headed hammer, there is a small dowel pin if I remember correctly.
Forget the WD 40 it is a water dispersant. Use plus gas.
Regards Geoff Peace.
Hi Taff
Just interested in your system of holding the piston on tdc.Can you explain the “cord down the plug hole” as it seems a good idea???
If you stuff a load of cord/rope into the combustion chamber using the spark plug hole it then lays randomly on top of the piston.
Ensure it is on top dead centre for any piston ie: valves closed. When the engine rotates that piston will rise and compress the rope to a point where it cant move any more. This offers the required resistance to the engine turning without damaging anything.
Ensure you leave rope out of the plug hole so when you turn the engine back a little the rope comes free and you pull it out - simples 
On a '93 car, I’d expect to have to remove the 21mm bolt in order to replace the timing belt.
I do not think this is a good idea at all. With all due respect to Dr. Eunos! I do not doubt that he, and many others have used this method with complete success. However, I have seen deformed piston crowns, bent con rods and gudgeon pins, even damage to big end bearings using this method. Not on MX5’s I hasten to add, but the principle is the same, Not easy faults to detect without a complete stripdown of the engine. If removal of the crankbolt is proving troublesome the force needed to release it can prove too much for one or more of the components listed. It is reasonably easy to fabricate a tool for the job from an inch and a half washer and a bar which will prove to be far preferable. In my opinion!
Regards Geoff Peace.
Correct, this method was taught to me by an ex REME tank technician and has worked every time for me, have even used a bit of twin and earth household electrical cable too, it coils around really well inside the combustion chamber. To undo the bolt go past the TDC of No1 cylinder so the piston is about a quarter the way down, slip the chord into the spark-plug hole and rotate the crank bolt anti-clock as viewed from the front until it locks, then continue with the breaker-bar till the bolt is loosened, re-tightening is the same proceedure making sure the piston is a quarter before TDC before inserting the chord and tightening the bolt.
I do have a crank-locking tool but still use this method…
Dr. Eunos
I do have a crank-locking tool but still use this method…
Now you really do have me perplexed Taff. If you have the correct tool why use a makeshift method? I would have thought it would be much easier with the correct tool! Just as an observation, I would not think the method in question would ever be used on a tank engine. three quarter and one inch drive sockets would be the order of the day! The army were sticklers for using the correct tools, many manufactured by Churchill at some exorbitant price.
Regards Geoff Peace.