Spelling, grammar and punctuation count !

WOW, that was hard to read. (I can't make sense of it)

Please proofread what you type.  If you can't be bothered, why would we be bothered to help you?

im not quite sure about that as would I not see smoke wen the engine does start up

Possible you have a defective head gasket, a small crack will allow water into one (or more) of the cylinders. I had this happen on a 1275 that's in my Moke.
Take the spark plugs out and try the starter, if any water vapour comes out then you have gasket issues.
Does it turn over with the spark plugs out?

okay sorry i needed to be more specific the engines starts up just fine wen it turns over but to get it to turn over I either need two batteries to get tehbstarter to turn and even then it it chances wrong witch is most time it cant turn the engine over but once I get the starter to turn the engine over it starts up fine for the most part so its not the part as it has efisient sark the timing is right and so on its just that inisual turn over that is the struggle 

Describe "struggling to start"
1. Does the starter turn slowly, to slow to help the engine fire?
2. Does the engine try to fire but won't catch - occasional cylinders firing, sputtering to life etc?
3. Is it better or worse when the engine is warm or cold?

20 thou oversize isn't all that much difference, assuming it was properly done with the right tolerances in bearings, ring gaps etc. (Lets assume it was.)

1. The battery could be tired, weak. Try replacing it or boosting with a known good battery. If the battery is good, check and clean the connections at the battery, the connections at the solenoid and the starter and the ground from the engine to the car body - there should be one near the clutch housing. If the engine ground is one of those bare braided wire type, inspect it carefully and replace it if it doesn't look like new - they corrode internally and eventually increase resistance. If all the above are good, then suspect the solenoid and/or starter motor is getting tired. A tied starter will crank more slowly and with less force but you may not notice it as it happens so gradually.

2. If the starter motor is cranking adequately, the next thing to check is appropriate starting conditions, i.e. proper starting procedure and tuning. When the engine is cold, you will very likely need to apply the choke. As you get to know the car, you will know how much choke it needs. Crank the engine in neutral with your foot OFF the clutch. (The clutch mechanism applies axial thrust to the crank increasing resistance.

Do NOT mess with the timing and carb at the same time - you may only compound your difficulties. 

Check the ignition timing. The specifications differ depending on the particular Mini engine, but 6 deg to 10 deg. static (engine off) advance would be OK for starting. If the car has ignition points, check the points gap with the points on a cam lobe. Adjust to spec. Check to see that (if you have it) the vacuum advance is properly connected. It doesn't activate until the engine is running, but is worth checking. It would have a small vacuum line running to the carb.  If it is disconnected or broken, it could result in an air leak to the carb. Check the spark plugs are in good condition and properly gapped (Don't thrust new plugs to be gapped correctly.) Check the spark plug wires and the coil connections are shiny and tight. A tired coil will produce a weak spark and poor running.

At the carb, check that an air cleaner is installed and in good condition. Check that the throttle and choke mechanisms are properly connected and functioning smoothly. When you apply choke, the mechanism opens the throttle proportionately ("fast idle"). Make sure the carb has all the hose connections it needs - varies depending on age of car and type of carb. A disconnected hose etc. may result in an air leak to the intake system. does the dashpot damper have oil in it?

3. Normally an engine is stiffer when cold. As it warms up, the bearings etc. run freer and the engine smoother. However, if an engine is built "too tight", heat will make it run stiffer. Rare, but it happens. Starter motors, especially older ones, can also be affected by their temperature.

hello I'm a new Classic mini owner 

my mini is struggling to start as my guess to way it is struggling is because the engine has 20thou over sided pistons and it's still using the original starter

 

if anyone can help I will be very grateful