Freeing up an old Portescap motor / gearbox

[John_Hughes]

A kit-building job which has just come to me includes a Kean Portescap motor and gearbox, but a quick check reveals that though it's not quite seized up, it's certainly well on the way to being so.

 

I suspect that the problem is that the old lubrication has dried up over the years and is now acting as rather effective glue. Any suggestions as to a safe way of freeing it up would be most welcome!

 

Thanks in advance!

 

 

 

[The Johnster]

Despite the 'ooh, it's a Portescap' factor, I don't see why this should be any different to any other drivetrain in which the lube has solidified.  I use Maplin's rattlecan spray 'Switch Cleaner'; the spray is powerful enough to blow most of the crud out on the first go, then you go off and have a cuppa while it soaks in, then have another go; I have yet to encounter anything so recalcitrant as to not be spotless at this stage, but if it is you just keep going until you run out of crud, or tea.

 

Now leave if overnight while the Maplin's stuff evaporates, and you are ready for a very light application of new lubricant.

[ScRSG]

I've had one or two of these go "tight" in my time. The way I found to help was, first to remove the motor from the gearbox, It is likely that the motor is ok and will run freely off the box. You can them manipulate the gears by hand and they should begin to free off, by all means follow the advice above to help with any kind of cleaner and once free re-lubricate lightly.

[Michael Edge]

Wash the pink grease out with GT85 (works like WD40 but is much kinder to plastics) and lightly lubricate the spur gears.

[John_Hughes]

Thanks to all for the help. The motor indeed runs well, so I'll go the GT85 route and hope for the best. I must admit that the product is new to me - I've not had a bike since I was about 14!