Morris Minor Owners Club

Morning all.

Recently I've started to experience a bit of a surge/kangaroo when only lightly on the throttle but particularly when going downhill in top gear.

Any idea what this could be? Ruled out fuel as pushing throttle removes the issue, perhaps slightly tooadvanced (although no pinking when going up hill)

First proper run since changing centre main and big end shells and the oil pressure isn't much better. Sits at 35psi when cruising at 60 and goes down to 15 when idle....

What was the condition of that main bearing shell? Was the crankshaft in good shape? No point in changing bearings in a worn crank - apart from a temporary waste of money. There may be other reasons for your low oil pressure readings.

sorry, didnt see the reply. The main bearing was in decent nick - no ridges, per this thread viewtopic.php?t=75072

When driving back i noticed that my speedo was significantly overreading - was sitting at 35psi when doing 50mph (on GPS) and around 40psi when doing 60. I put some STP oil treatment in also and the hot idle went up to 15-20psi.

The surge was also solved by retarding the ignition a tiny bit, strange as it wasn't pinking, but must have been too far advanced - went away on drive back!

Have you checked the pressure relief valve?