Thanks crosbyman and Tubs once again for your much appreciated input……..Mr Mohat’s  article and the You Tube on expansion and contraction are very interesting.

I am pleased to report that I have spark…….one side has a bigger spark than the other. I swapt the spark plus around and installed new HT leads, but it didn’t make any difference…….what that indicates I’m not sure. Maybe I will wait until and see how the motor runs.

Regarding the dismantling of the gearbox and pump, I got that apart ok. I found that by lowering the drive shaft with the gear, that there was a steel ring round the top of the gear and by sliding the ring up it exposed a steel drive pin, which slid out easily…….simple but very effective.    I managed to get the pump apart. All appeared ok and worked well later when tested in our it laundry tub. One point I would like to make though, is to be very careful undoing the top valve which has a the thin hexagonal section with the adjustment screw in the middle.

It is  easy to have  the spanner slip and damage the hexagonal end of the valve so I mounted the pump body (which goes into the gearbox) in my lathe, making sure it was tight in the chuck and using an  on old car inlet/exhaust valve, fitted into the tailstock  chuck, I then brought the face of the valve up to the hexagonal section, so that it was just touching and  locked the tailstock from moving. I then fitted the spanner and gave it a gentle smack with a hammer, which broke it loose…….”Hey Presto” …… no damage !……….Hope this helps someone dealing with similar problem.

Thanks again

Monte NZ