Setup info for PVP 251 Motor
Important: Use only fuel supply system with, filter, vacuum pump, regulator & pressure gauge "click here"
Specification
Cylinder and Piston
| Bore: 54,00 maximum 54,035,
Stroke: 54,5 mm |
Piston /Cylinder Clearance:
minimum 0.05 mm. |
Squeeze 0.8 in the front cylinder (
insert 2.25 )
Squeeze 0.85 in the rear cylinder ( insert 2.2 ) |
Ignition
| Ignition unit: PVL | Ignition timing: 6.0 mm before T.D.C. | Spark plug: NGK B10EGP |
Rotary valve
| Rotary valve timing: model 2006 | Opens: 48.5 mm. before T.D.C. | Closes: 27.3 mm. after T.D.C. |
Primary drive
| clutch axle / rear crankshaft | Reduction | |
| Primary reduction ratio: | 58 : 26 | 2.2308 |
Gearbox
| Standard | Reduction | Option | Reduction | |
| 1 st. gear | 32 : 12 | 2.6666 | 31 : 13 | 2.3846 |
| 2 nd. gear | 29 : 14 | 2.0714 | 28 : 15 | 1.8666 |
| 3 rd. gear | 22 : 14 | 1.5714 | 24 : 16 | 1.5 |
| 4 th. gear | 23 : 17 | 1.3529 | 25 : 19 | 1.3157 |
| 5 th. gear | 22 : 18 | 1.2222 | 26 : 22 | 1.1818 |
| 6 th. gear | 23 : 20 | 1.15 | 21 : 19 | 1.1052 |
| Gear box oil | In primary drive | In gear box |
| Castrol Syntrax 75-90 | 0.2 Liter | 0.5 Liter |
Recommended sprocket for motor and rear axle
| Motor: 22 T. 23 T. & 24 T. | Rear axle: 29 T. 30 T. & 31 T. |
Chain
| To not overload the chain use minimum 22 T. on the motor and minimum 29 T. on the rear axle, for front and rear sprocket together have minimum 52 T, so you not overhead the chain. | For lubrication of the chain, use Molykote Longterm W2 |
Fuel supply system
| Fuel pump | Fuel pressure | Pressure Regulator | Fuel Filter |
| Mikuni puls pump | 0.15 to 0.18 Atu. | Part no. 4010 | Part no. 4036 |
Torque for bolt and nuts
| M6 | M8 | M18x1,5 | M22x1.5 | Plug screw |
| 10 Newton | 20 Newton | 90 Newton | 100 Newton | 20 Newton |
Petrol (Gasolin) & Oil
| Petrol: Unleaded minimum
octane 100
(Shell V-Power 100) or (Elf: MIST 31 or SK35) |
Oil: 4% mixture Castrol A747, Castrol XR77 or Elf. HTX 976 |
Carburetor : Dellorto VHSC 39.5
| Jet needle | Needle jet | Main jet | edler jet | Carburetor piston | Needle valve |
| K24 clip position 2 from top | DQ 268 | 188 to 195 on front cylinder
190 to 198 on rear cylinder |
55 or
120 with 45 pilot jet |
40 | 250 |
Always Change oil then you open gear box or primary drive
After 4 races weekends
| Description | Qty. | Part number |
| Piston, piston pin, c-clips & Piston ring | 2 | 394, 395, 396 or 397 |
| Big end needle bearing in rods | 2 | 223 |
| Oil seals between crankshaft and primary drive | 2 | 812 |
| Oil seal behind water impeller | 1 | 806 |
| Oil seal for clutch drum | 1 | 820 |
Also change this after 8 races weekends
| Description | Qty. | Part number |
| Rods | 2 | 220 |
| Small end bearing for rod | 2 | 390 |
| Main bearing for crank shaft | 4 | 860 |
| Bearing for end of crank shaft | 2 | 848 |
| Oil seal behind ignition & inside oil seal with water pump | 2 | 806 |
| O-Ring on exhaust | 4 | 772 |
| Bearing in gearbox 6304-C3 2-RS ø20/52x15 | 1 | 852 |
| Bearing in gearbox 6203-C3 2-RS ø17/40x12 | 1 | 845 |
| Bearing in gearbox 6203-C3 ø17/40x12 | 1 | 844 |
| Bearing in gearbox 6205-C3 ø25/52x15 | 1 | 856 |
| Oil seal on shift shaft | 1 | 802 |