P.O. Box 372, Sevenoaks, Kent
TN15 0WR

Tel: 01732 760337
Fax: 01732 760339

 

RS 250/ RGV 250

Road Tuning

We have a wealth of knowledge on RGV engines dating back to our experience in the British Supersport 400 Championship and in more recent years Aprilia RS250's which have the later RGV motors in them. We can tune the engine either for the road or track. The barrels are ported and flowed, the heads reworked and the powervalves blended in to give more power and smoother delivery. This work is priced according to budget Stage 1, 2 or 3. All you need to do is send in the top end of your engine, heads barrels inc. powervalves. For an extra £30 we strip/clean/rebuild the powervalves.

These prices are for when sending in the parts, if you send in the engine see the top-end rebuild prices.

RGV and RS 250 Road 300 cc Conversion

Our 300cc Conversion is well proven over the last 10 years, during which time we have improved and updated the specification and corrected any early teething problems. The main advantages of the 300cc is the far wider spread of power and the increased torque whilst the tuning and porting gives a big increase in top-end power.
The conversion consists of overboring the barrels to 61mm and tuning to Stage 3 spec. renicosiling the barrels. Stripping/modifying/rebuilding the powervalves. Remachining the cylinder heads and machining 'O' ring grooves. The pistons we use are specially made forged Wiseco race Pistons. The conversion is supplied assembled and ready to go, just send in the complete top end of your engine i.e. heads/barrels/P.V's. If you would rather we rebuilt the engine, we will strip and rebuild the engine and rebuild the crank and fit the conversion.

300cc Conversion	£765
Strip & rebuild engine + parts	£240
Strip & Rebuild crank + parts	£40

 

Rebuilds

We specialise in engine rebuilds. All parts are accurately measured,checked and meticulously rebuilt as you expect from a race workshop. We can re-nicosil your damaged or worn cylinder or exchange it for a reconditioned unit. We have a massive stock of genuine parts for the RGV and RS250 engines.

Stan Stephens Special Edition Cylinder Heads

Pair of new Aprilia RS250/ Suzuki RGV250 Special cylinder heads. They are a completely new design. The heads are red anodised and feature upright central plugs with detachable combustion-chamber domes. The heads and domes are fitted with 'O' rings, The heads have far greater water volume around the domes resulting in a cooler running engine. The combustion chamber domes use the latest 2-stroke Grand-Prix technology with a dual angle squish area and a toroidal shaped combustion area.We also produce them for our 300cc conversion. We also stock special power-valves and all engine spares.

SS Cylinder Heads

£395 per pair

Special Edition Cougar Powervalves

Suzuki RGV250 and Aprilia RS250 Cougar Power-valves, set of four, we will also supply them singularly. No more power-valve problems, these state-of-the-art designed power-valves are vastly superior to the standard ones and elliminate the PV troubles. They have a much improved shape for more power and port gas-flow. They have a high-tech coating process which coats the PVs with a hard wearing almost friction-free surface. The coating also stops carbon building up on the PVs. We produce special heads, 300cc conversions, tuning and engine rebuilds and stock most engine spares.

Cougar Powervalves x 4

£395 or £100 each

2008 Road Race Season

The good news for 2 stroke racers is that BMCRC (The organisers of the MRO series) and most other clubs are running "Formula 400cc" races as opposed to "Supersport 400."
The big difference is that the old "Supersport 400" was for 250cc two strokes and 400 cc four strokes. The new formula rules are for 400 cc two strokes and 400cc four strokes.
With the RS250 / RGV250's lighter weight, better handling, braking and with 400 cc as well this is the breakthrough we have asked for and needed for years.
For the 2008 race season we are offering a full race version of our well proven and popular 300 cc conversion.
We are also working on a range of big bore - long stroke race only conversions.

Aprilia RS250 / Suzuki RGV 250 300cc Race Tuned Conversion

Our 300cc (61 mm bore) road conversion has been well proven over the last ten years. The main advantages of the 300 are the far wider spread of power and increased torque.
For the 2008 race season we are offering a race 300cc conversion. The main differences will be ; the porting will be our SS400 race porting, the heads will have a higher compression and different combustion chamber shape and a tighter squish clearance. The barrels will be ceramic plated instead of nicosil, and the crowns of the pistons will be ceramic coated.
The conversion will consist of ; overboring your barrels to 61mm and tuning to Supersport 400 spec, ceramic replating the barrels, stripping/modifying/rebuilding the powervalves, remachining the cylinder heads and machining the o-ring grooves. We supply, specially made for us, Wiseco forged race piston kits. The conversion is supplied assembled and ready to go. Just send in the complete top end of your engine. i.e. Heads,barrels,powervalves, complete, head nuts and washers.
If you would rather we rebuilt the engine, we will strip and rebuild the complete engine.

300cc race conversion	£850
Strip and rebuild engine + parts	£240
Strip and rebuild crank + parts	£40

Supersport 400 Race Tuning

Supersport 400 is a race class we have always been involved with. During the late 1980's and early 1990's it was a full British Championship class. We tuned and prepared the engines of the works Kawasaki Team Green KR1S's for John Reynolds and later tuned the RGV engines for Jeremy McWilliams and many other top British Championship riders. Over the next few years the Superteen Series was for tuned RGV's and was run at British Championship meetings. Riders like David Jefferies, Michael Rutter, James Haydon, Darren Mitchell, Jason Vincent and the late John Peacock all emerged from the Superteens.
Since those heady days SS400 racing has been at club and MRO level.
We have been carrying out more extensive Dyno testing on the Aprilia RS 250 and we are now obtaining over 70 BHP using standard carbs and air box!
We are now booking in engines for the 2008 season tuned to our new specifications. Customers can have just the top-end modified or the complete engine.

Modifying the barrels heads and powervalves	£300
Flowing the crankcases	£100
Stripping/rebuilding / trueing the crankshaft and fitting new centre seal (+ parts)	£50
Stripping/rebuilding engine and gear box (+ parts)	£240
Forged Wiseco race piston kits, each	£70