NEW. TWIN CRANKCASE DRIVE SIDE OIL SEAL

(FOR DYNAMO TWINS FITTED WITH AMC GEARBOXES.)

If the factory had still been in existence they would have got round to doing this modification eventually.

The old arrangement never did keep the oil out of the primary chain case. Many modifications have been tried such as taps in oil pipes (a really silly idea as you have to remember to turn them on and most people use a petrol tap fitment reducing the bore of the pipe with very expensive consequences. Even with taps fitted, at the end of every long run the old problem was still there. Oil transfers from the crankcase to the primary chaincase though back pressure. With my modification the oil pressure has to escape vie the correct route out of the pressure release valve which is sited on the end of the crankcase incorporated in the sprocket nut can comes from higher up in the engine, and above all the oil splashing about at the bottom of the crankcase.

FIG 1.

Fitting is easy and can be done in an hour. Take off your primary chaincase and remove your sprocket nut. Part your primary chain and remove sprocket and SPACER (shown FIG 2 on the left hand side. Tap in tight fitting oil seal supplied shown with specially made replacement spacer shown in FIG 2 on the right hand side. Push in the new spacer and replace sprocket/nut/chain and primary chain case in reverse order and its done.

FIG 2.

Not only with this stop oil transferring it will greatly reduce the oil draining on its own accord into the primary chaincase as the point of entry is now higher up. Put it on its centre stand and make sure the pistons are at top dead centre and you will even have more room for the oil to collect due to the volume of the con rods no longer being at the bottom.

Cost of complete kit with fitting instructions, £27 including postage.