So bit of an update, engine was running well when I done the 20min run in until a knocking rattle sound appeared.
Had a look under the sump and knowing I had previously mixed up the con rod caps, and couldnt see much.
But I thought it would be best to have another go at matching them as I was unsure where the sound was coming from and it was the only logical option I could come up with.
Got the engine out and re did the matching and now I'm happy its good, started her up and sure enough the rattle is still there!
so last night I had listen with a bar in my ear, or though I didn't hear the same noise, I was hearing more noise from the drivers side cat.. I angled my head between the cat and sump and sure enough it was a bit louder on the cat side!
I took the y section with cats off, gave it a shake and sure enough lots **** rattling around and also some bits come out the pipes! cut open the cats and removed all the remaining ****, welded them up, refitted and hey presto no rattle!
But now its having problems starting, seems the spark is very weak after entering the dizy..
I changed the rotor and cap and still no luck.
I try for a while and of course it floods and all the plugs are wet with fuel.
Also it seems it is a bit random weather it wants to spark at all!
once it runs it seems fine, the timing is good, got 12v at the coil both sides, the rotor and cap are good clean with no big scratches to arc across and got brand new genuine leads.
Bit unsure on where to go from here, finally seem to get it sorted to get yet another issue, Dam landys! lol