Morris Minor Owners Club

it is true, i've done it. after loads of help from numerous people on here in relation to the 'box, ive swapped my standard 803 running gear, with a 1098 and a 950 box, whilst still retaining the long stick. i really appreciate the advice i was given about the box, it still looks original, whilst shooting off a rate that made me wet myself...ok, so the speedo still isnt connected, and realistically, it still is no rocket machine, but the difference is astronomical! it is actually drivable...
okay, so the good bit over...teething problems...
the engine and box was removed from my dads car(he's putting a 1275 in his saloon) and was running absolutely fine bar a clutch issue, which was sorted by buying a clutch. but...when installed to my car it has started to miss when i get it to around 3500rpm...now this confused me as it can't be the air mix as it was fine on dads, and im pretty sure we haven't touched the distributer...so it's all a wee bit confusing! so...if anyone has any lovely suggestions, please feel free to vent them...
again, thanks to all who helped, really really appreciated!
*C*

A weak fuel pump?

Might well be a loose connection in your wiring - set off by a certain vibraton level.
Most likely causes of repeatable missfiring is the electrics. The Minor electrics are relatively simple, so working through it logically may find it.

If it''s a flat spot more than a missfire, then look on the fuel side.

oh i see...so no simple adjusting then?! pants! i shall investigate......now...!

okay, i looked around, tried to spot any things i may have over looked when i did the swap, but nothing stands out as being obvious. i shall steal my dads fuel pump and see if that does anything, im kind of hoping it is that, because the car was off the road for the best part of 20 years...so i can accept that! if anything else pops into your minds that might also cause this "miss fire" then please let me know!

okay, the dash pot is topped up, tried a different fuel pump, can't see anywhere obvious that it might have a loose connection...so...what next??!! if there was a loose connection, where would it be that it is most likely to cause this kind of problem? please please help, the car is my daily use car and currently i don't want to drive it just in case i damage the engine! sniff sniff! :'(

Is it the correct carb for the 1098 ? Is the air filter all choked with oiley muck? Try without filter. Coulkd be mixture - or more likely timing/dizzy problems. Is the vacuum advance connected and working as designed ?