SC500, finished project ?

Work (and some pleasure) had limited the amount of shed-time on the SC500. Both myself and Gavin had had problems getting the bike to run on the ignition components we’d had from Rex Caunt Racing . Debbs had sent to some replacement coils to the other Malcolm Herbert in Hereford, but something more fundamental was going on here. Speaking to Rex, moved to the designed for TY ignition and so spent a morning with him and his workshop fitting a new charging coil and getting it set up correctly.

The bike ran and managed to fill the corridor outside the workshop with smoke and back in Herefordshire managed to complete the bike in the 2 days I had before the first race of the year at Clyro.

Finishing touches

So, to run through the work on the bike and what I’d done with it during the 5 month period of restoration;

|Bars|Renthal Desert Bars, sourced from LG Racing in Pontrilas|
|Controls|Domino levers and a Gasser throttle, the latter from Motolink |
|Wheels|these are original and didn’t need respoking, just tightening|
|Tyres|Golden Tyre set, 100/100 R18’s on the rear, not too big in terms of profile|
|Plastics|Though the side panels are original and good condition, the mudguards were not so good. Replacement grey (rather than silver) from DC Plastics |
|Carb|The original Mikuni VM38 was badly worn, so decided to replace. Could have got a replacement from Allens Performance , but went for Dell’Orto equivalent from Eurocarb -> |
|Engine spares| Seals from Motolink, with the bearings sourced locally in Hereford. New piston and ring (original bore) came from North West Vintage Cycle Parts -> |
|Ignition | From Rex Caunt Racing, see above and other articles|
|Exhaust|Original unit, though considering Circle F replacement at some point|
|Rear Shocks|These are 340mm units from [Rock Shocks -> ] |

In terms of work on the bike, the frame has been cleaned up and resprayed in Hammerite Satin, along with the swing arm and bash plate. The forks were in good condition and unlike the MX250 project they didn’t need rechroming.

Completed and running (for now)

Smaller version of this image

The engine rebuild was straightforward and I removed the balancer shaft during the rebuild (this doesn’t seem to have much of a negative impact with engine vibration). The gasket set was found on ebay. The main problem is a pretty screwed flywheel / rotor nut, which was a bit mangled and needs replacement. The barrel was on the original bore, though the piston in the bike had a chunk missing out of it. New piston and ring along with a honed barrel did the trick on the rebuild.

And does it go ? I can’t get it out of 2nd gear in my small field.

Leave a Reply

Your email address will not be published. Required fields are marked *