Setup info for PVP 252 Motor

Last update 18-05-2022                             Print in PDF

Important: Use only fuel supply system with, filter, vacuum pump, regulator & pressure gauge "click here"    

Specification

Cylinder and Piston

Bore: 54,02   maximum  54,035,

Stroke: 54,5 mm

Piston /Cylinder Clearance:

minimum 0.05  mm.

Mesure the squeeze with a 1 mm. solder wire it have to be abot 0.7 mm.

You can change the squeeze by change the head insert, the no. on the insert de describes how deep the the insert go into the cylinder, for example 2.2 go 2.2 mm. down into the cylinder.

If the cylinder have got new Nikasil, it is some time shorter after that, then check the Squeeze, it have to be minimum 0.65 mm.

The motor is also approved with 113 mm. rod, you can use together with piston there have part no. 393, 394, 395, 396 and 397, and you can start with a cylinder diameter of 54.0 mm. this piston is cheaper, but this piston is 11 gram heavier than piston no. 3965 or 3975

The motor is also approved with 120 mm. rod, then you use a 5 mm. aluminum gasket under the cylinder, but it will only work good if you have the motor with the 2014 update, or if you have the motor model 2017

Ignition

Ignition unit: PVL Ignition timing:  5.8 mm before T.D.C. Spark plug:  NGK B10EGP or NGK R7282-11
Spark plug connector for NGK B10EGP is:   part no. 898 Spark plug connector for NGK R7282 is:   part no. 899
If you have  problem with it burning a hole in the middle of the piston then reduce the ignition timing from 5.0 to 5.8 mm. before T.D.C. I f you have  problem with detonation then increase the volume of the combustion camber, or use fuel with higher octane.

Rotary valve

Rotary valve timing Opens: 51.4 mm. before T.D.C.   Closes: 28.8 mm. after T.D.C.
Part no. 281, 282 or 283    

Primary drive

  clutch axle / rear crankshaft Reduction
Primary reduction ratio: 58 : 26 2.2308

Recommended gear box for following races tracks 

standard 1, 2, 3, 4, option 5, 6 Hockenheim, sprocket 24:31    Magny Cours, 
standard 3, 4, option 1, 2, 5, 6  Dijon, sprocket 24:30
1: 12:31  3 and 4, standard  2, 5 and 6 option  Assen,   sprocket 24:31

Gearbox

Standard  Reduction Part number Rotax number on gear
1 st. gear low 32 : 12  2.6666 611 : 512 4949 . 467
1 st. gear medium 31 : 12 2,5833 613 . 512 5904 : 467
1 st. gear high 31 : 13 2.3846  615 : 514 4944 : 462
2 nd. gear low 29 : 15 1,9333 621 : 523 4964 : 4950
2 nd. gear high 28 : 15 1.8666 624 : 523 4080 : 4950
3 rd. gear 22 : 14 1.5714 632 : 542 5924 : 5910
4 th. gear 23 : 17 1.3529 642 : 542 5933 : 5910
5 th. gear 22 : 18 1.2222 654 : 554 5954 : 5940
6 th. gear low 23 : 20 1.15 663 : 564 5976 : 5966
6 th. gear high 21 : 19 1.1052 666 : 566 5975 : 5965
Gear box oil In primary drive In gear box
Castrol Syntrax 75-90 or ELF HTX  740 0.2 Liter 0.4 Liter

Important: Control the oil level in the gear box and primary drive before you start the races day, if the motor stand long time can some of the oil move from the gear box in to the primary drive, and then begin to pump oil out to the plastic bottle, because the level is to high in the primary drive.

Recommended sprocket for motor and rear axle 

Motor: 22 T.  23 T.  24 T. 25 T. & 26 T  Rear axle: 29 T. 30 T.  31 T. 32 T & 33 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:

 Pro chain spray ( PN. 4024)

Fuel supply system

Fuel pump Fuel pressure Pressure Regulator Fuel Filter
Mikuni pulse pump 0.15 to 0.18  Bar. Part no. 4010 Part no. 4036

 

 

 

Torque for bolt and nuts 

M6 M7 M8 M18x1,5 M22x1.5
10 Newton  13 Newton 20 Newton  100  Newton   100 Newton
Plug screw 
20 Newton

Petrol (Gasoline) & Oil

Petrol:   
Aral Octane 102 unleaded
Elf:  SK35 
Elf: LMS
Oil: 4% mixture 
Castrol XR 77
 Elf.  HTX 976.
PM Xeramic Castor Evolution 2T 

Carburetor : PVP 42 mm.

Jet needle Needle jet Main jet Needle jet Air screw  Needle valve
K24 clip position 3  from top

Motor with update clip 2 from top

DQ 270 210 to 220 on front and rear cylinder

Motor with update 215 to 220

120 with 44 pilot jet

about 1.5 round out 250

I will recommend you to change parts in the motor after this driving time.

Always Change oil then you open gear box or primary drive

After 750 km. 

Description Qty. Part number
Piston, piston pin, c-clips & piston ring ( for 115 mm. and 120 mm. rod) then you use PVL Ignition

If you use RTD ignition, then will recoment you to change the piston after 500 km. it will begin to crack and it will be very expensive if the piston collapse.

2 3965 or 3975

After 3 races weekends or 1500 Km. 

Description Qty. Part number
     
Main bearing  4 860
Big end needle bearing in rods 2 223
Oil seals between crankshaft and primary drive  2 812
Oil seal behind water impeller or if there come water out from the drain  1 806
     

Also change this after 6 races weekends or 3000 km.

Description Qty. Part number
Rods, crankshaft pin  2 226 or 228 and 227
Side washer 4 222
Small end bearing for rod 2 390
Bearing for end of crank shaft 2 848
Oil seal behind ignition & inside oil seal with water pump   2 806
Oil seal for clutch drum 1 820
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