YPVS 350
When a bike magazine recently did an article on engines, they asked myself and some race engineers our favourite engine. Most chose exotic race engines but I chose the YPVS 350! The YPVS has always been a favourite of mine and an engine which I have had an enormous amount of success with in many different guises. We have raced them in Proddy racing, Formula 2, Drag racing, Formula 2 sidecars, Hill-climb bikes, Jedi hill-climb cars, Formula 1 hovercraft and Quads. In those varying classes we have won British Championships and European Championships and set World Speed records at Bonneville Salt flats. For the road we built the famous "Yammagammas" in the 1980s and recently we have built the "Yammarillas" using the Aprilia RS250 rolling chassis.
| Strip and rebuild engine plus parts | £360 |
| Strip and rebuild crank plus parts | £60 |
| Rebore plus parts each | £30 |
| Modify and match crankcases | £100 |
| Lighten Flywheel | £50 |
| Stage 1 Tune | £120 |
| Stage 2 Tune | £240 |
| Stage 3 Tune | £360 |
| Rebush PV housing each | £40 |
| Machine damaged crankcase main bearing housing | £150 |
As the YPVS engine has got older a couple of fairly terminal problems have arisen. The inner power-valve holders/bushes wear in the housings in the barrels. The R/H main bearing wears the bearing housing in the crankcase. We machine out the PV housings in the barrels and fit steel inserts. To repair the damaged crankcases, we line-bore the R/H main bearing housing and fit an oversize main bearing.
A lot of the YPVS engines we rebuild now are for classic bikes and we offer the complete service of bead-blasting, aqua-blasting, stove enamelling, polishing and zinc-plating all fittings.
| Aqua-blast crankcases | £75 |
| Bead-blast and paint barrels, pair | £80 |
| Bead-blast and paint head | £40 |
| Bead-blast and stove-enamel clutch cover | £80 |
| Zinc-plate small part | £1 |
| Zinc-plate large part | £2 |
Information: We are only machining/assembling your engine/parts. The responsibility for setting up the bike, filling/bleeding the oils and water, using the correct fuel, plugs, jetting etc is undertaken by the rider/mechanic, whom it must be assumed has a good mechanical knowledge. Due to the performance increases with our tuning and conversions they are intended for track days and competition use only, and as such no warranty is offered or implied.