Part Number Description Skirt Crown Type Ring Pack Barrel Type
K 27 Piston K standard size for use with petrol Full skirt Cone Two compression, one oil control Iron
K 27R Piston K  standard size 8:1 compression ratio for use with alcohol fuel Full skirt Cone Two compression, one oil control Iron
K 27/ 0 Piston K +1/2mm for use with petrol Full skirt Dome with valve cut outs Three compression Iron
K 27/ 2 Piston K 6:1 +1/2mm compression ratio       Iron
K 27/ 3 Piston K 7:1  +1/2mm compression ratio       Iron
K 27/ 4 Piston KTT MK I-III standard size 7:1  compression ratio for use with 50/50 petrol benzol mixture Full Skirt Dome with valve cut outs Two compression, one oil control Iron
K 27/ 5 Piston KTT standard size 6:1 compression ratio for petrol Full Skirt Dome   Two compression, one oil control Iron
K 27/ 6 Piston KSS standard size for use with 50% petrol benzol mixture Full Skirt Dome with valve cut outs Two compression, one oil control Iron
K 27/ 6/0 Piston KSS +1/2mm for use with 50% petrol benzol mixture +1/2mm Full Skirt Dome with valve cut outs Two compression, one oil control Iron
K 27/ 7 Piston KTT MKI-III 8.5:1 standard size compression ratio for use with Discol PMS2 Full Skirt Dome with valve cut outs Two compression Iron
K 27/ 8 Piston KTT MKI-III standard size 10.25:1 compression ratio for use with Discol RD1 Full Skirt Dome with valve cut outs Two compression Iron
K 27/10 Piston K from KSS3800 standard size Slipper Dome with valve cut outs Two compression, one oil control Iron
K 27/10/0 Piston K from KSS3800  +1/2mm Slipper Dome with valve cut outs Two compression, one oil control Iron
K 27/11 Piston K 8.75:1 standard size for use with alcohol from KSS3800 Slipper Dome with valve cut outs Two compression, one oil control Iron
K 27/12 Piston KTT400-on standard size for use with 50/50 petrol benzol mixture Slipper Dome with valve cut outs Three compression Iron
K 27/13 Piston KTT400-on standard size for use with Alcohol Fuel Slipper Dome with valve cut outs Three compression Iron
K 27/14 Piston KSS Ring Below Pin standard size to engine number KSS7475. 6.8:1 compression ratio. Replaced by K27/17 Full Skirt, ring below pin Dome with valve cut outs Two compression, two bevel oil control Alloy
K 27/14/0 Piston KSS  Ring Below Pin +1/2mm to engine number KSS7475. 6.8:1 compression ratio. Replaced by K27/17/0 Full Skirt, ring below pin Dome with valve cut outs Two compression, two bevel oil control Alloy
K 27/15 Piston KTT MK VI,Vll,Vlll standard size Slipper Dome with valve cut outs Two compression, one slotted control Alloy
K 27/16 Piston KTT MK Vl,Vll,Vlll standard size Slipper Dome with valve cut outs Two compression, one slotted control Alloy
K 27/17 Piston KSS MKII standard size slipper type used from KSS 7476. 7.5:1 compression ratio, 8.4:1 with compression plates removed Slipper Dome with valve cut outs Two compression, one slotted control Alloy
K 27/17/0 Piston KSS  MK II +1/2mm slipper type used from KSS 7476. 7.5:1 compression ratio, 8.4:1 with compression plates removed Slipper Dome with valve cut outs Two compression, one slotted control Alloy
K 27/17/1 Piston KSS MKII +1mm slipper type used from KSS 7476. 7.5:1 compression ratio 8.4:1 with compression plates removed Slipper Dome with valve cut outs Two compression, one slotted control Alloy
K 27/26 Piston K standard size 7:1  compression ratio Slipper Dome with valve cut outs    
X8 PistonKTT MK1-III standard size 12:1 compression ratio for RD1 or methanol Slipper Dome with valve cut outs Three compression Iron
           
M 27 Piston MOV, MAC  standard size, 6 to  6.75:1 compression ratio depending on compression plates fitted in year Slipper Dome with valve cut outs Two compression, one oil control Iron
M 27/  AS/WS Piston MAF  standard size complete with W.S. ring       Iron
M 27/ 0 Piston MOV, MAC + 0.020" 6 to  6.75:1 compression ratio depending on compression plates fitted in year Slipper Dome with valve cut outs Two compression, one oil control Iron
M 27/0AS/WS Piston MAF  +1/2mm. complete with W.S. ring       Iron
M 27/1 Piston MOV, MAC  + 0.040" 6 to  6.75:1 compression ratio depending on compression plates fitted in year Slipper Dome with valve cut outs Two compression, one oil control Iron
M 27/1AS/WS Piston MAF  +1mm. complete with W.S. ring       Iron
M 27/ 2 Piston Iron MSS standard size, ring below pin stepped oil ring used up to MSS 3689 replaced by M27/3 with SL3/23 (slotted oil control ring) 6 to  6.4:1 compression ratio depending on commpresiion plates used Full skirt, ring below pin Slight dome Two compression, two stepped oil control Iron
M 27/2/0 Piston Iron MSS  + 0.20" ring below pin stepped oil ring used up to MSS 3689 ring replaced by M27/3/0 with SL3/41(slotted oil control ring) 6 to  6.4:1 compression ratio depending on commpresiion plates used Full skirt, ring below pin Slight dome Two compression, two stepped oil control Iron
M 27/3 Piston Iron MSS  standard size, ring below pin std, slotted oil control ring 6 to  6.4:1 compression ratio depending on commpresiion plates used Full skirt, ring below pin Slight dome Two compression, one slotted oil control, one stepped oil control Iron
M 27/3/0 Piston Iron MSS  +.020"  ring below pin std, slotted oil control ring 6 to  6.4:1 compression ratio depending on commpresiion plates used Full skirt, ring below pin Slight dome Two compression, one slotted oil control, one stepped oil control Iron
M 27/3/1 Piston Iron MSS  +.040" ring below pin std, slotted oil control ring 6 to  6.4:1 compression ratio depending on commpresiion plates used Full skirt, ring below pin Slight dome Two compression, one slotted oil control, one stepped oil control Iron
M 27/4 Piston Alloy MAC  standard size, 6.75:1 compression ratio, split skirt slipper piston Split skirt slipper Dome with valve cut outs Two compression, one oil control Alloy
M 27/5 Piston Alloy MAC +.020" , 6.75:1 compression ratio, split skirt slipper piston Split skirt slipper Dome with valve cut outs Two compression, one oil control Alloy
M 27/6 Piston Alloy MAC +.040" , 6.75:1 compression ratio, split skirt slipper piston Split skirt slipper Dome with valve cut outs Two compression, one oil control Alloy
M 27/7 Piston Alloy  MAC +.060" , 6.75:1 compression ratio, split skirt slipper piston Split skirt slipper Dome with valve cut outs Two compression, one oil control Alloy
M 27/9 Piston Alloy MSS   standard size, 6.8:1 compression ratio, split skirt for Alfin barrel Full split skirt Slight dome with valve cut outs Two compression, one oil control Alloy
M 27/10 Piston Alloy MSS +.020", 6.8:1 compression ratio, split skirt for Alfin barrel Full split skirt Slight dome with valve cut outs Two compression, one oil control Alloy
M 27/11 Piston Alloy MSS +.040", 6.8:1 compression ratio, split skirt for Alfin barrel Full split skirt Slight dome with valve cut outs Two compression, one oil control Alloy
M 27/13 Piston Viper standard size, 8.5:1 compression ratio, split skirt piston Alfin barrel Full split skirt Dome with valve cut outs Two compression, one oil control Alloy
M 27/14 Piston Venom  Standard size, 8:1 compression ratio, split skirt piston for Alfin barrel Full split skirt Dome with valve cut outs Two compression, one oil control Alloy
M 27/17 Piston Viper, Scrambler Standard size 9.3:1 compression ratio, solid skirt for iron barrel Full skirt  Dome with valve cut outs Two compression, one oil control Iron
M 27/18 Piston Viper +.020" 8.5:1 compression ratio, split skirt piston Alfin barrel Full split skirt Dome with valve cut outs Two compression, one oil control Alloy
M 27/19 Piston Viper +.040" 8.5:1 compression ratio, split skirt piston Alfin barrel Full split skirt Dome with valve cut outs Two compression, one oil control Alloy
M 27/20 Piston Venom +.020"  8:1 compression ratio, split skirt piston Alfin barrel Full split skirt Dome with valve cut outs Two compression, one oil control Alloy
M 27/21 Piston Venom +.040"  8:1 compression ratio, split skirt piston Alfin barrel Full split skirt Dome with valve cut outs Two compression, one oil control Alloy
M 27/22 Piston Viper, Scrambler +.020" 9.3:1 compression ratio, for iron barrel Full skirt  Dome with valve cut outs Two compression, one oil control Iron
M 27/23 Piston   Viper, Scrambler +.040" 9.3:1 compression ratio, for iron barrel Full skirt  Dome with valve cut outs Two compression, one oil control Iron
M 27/24 Piston Viper, Scrambler standard size 9.3:1 compression ratio, solid skirt for iron barrel Full skirt  Dome with valve cut outs Two compression, one oil control Iron
M 27/25 Piston Viper, Scrambler +.020" 9.3:1 compression ratio, solid skirt for iron barrel Full skirt  Dome with valve cut outs Two compression, one oil control Iron
M 27/26 Piston Viper, Scrambler +.040" 9.3:1 compression ratio, solid skirt for iron barrel Full skirt  Dome with valve cut outs Two compression, one oil control Iron
M 27/27 Piston Viper, Standard size, 9.3:1 compression ratio, split skirt for iron barrel Full split skirt Dome with valve cut outs Two compression, one oil control Iron
M 27/28 Piston Viper, Scrambler +.020" 9.3:1 compression ratio, split skirt for iron barrel Full split skirt Dome with valve cut outs Two compression, one oil control Iron
M 27/29 Piston Viper, Scrambler +.040" 9.3:1 compression ratio, split skirt for iron barrel Full split skirt Dome with valve cut outs Two compression, one oil control Iron
M 27/30 Piston Alloy MSS   standard size, 6.8:1 compression ratio, split skirt for iron barrel Full split skirt Slight dome with valve cut outs Two compression, one oil control Iron
M 27/31 Piston Alloy MSS +.020", 6.8:1 compression ratio, split skirt for iron barrel Full split skirt Slight dome with valve cut outs Two compression, one oil control Iron
M 27/32 Piston Alloy MSS +.040", 6.8:1 compression ratio, split skirt for iron barrel Full split skirt Slight dome with valve cut outs Two compression, one oil control Iron
M 27/33 Piston Venom  standard size, 8:1 compression ratio, split skirt piston for iron barrel Full split skirt Dome with valve cut outs Two compression, one oil control Iron
M 27/34 Piston Venom  +.020", 8:1 compression ratio, split skirt piston for iron barrel Full split skirt Dome with valve cut outs Two compression, one oil control Iron
M 27/35 Piston Venom  +.040", 8:1 compression ratio, split skirt piston for iron barrel Full split skirt Dome with valve cut outs Two compression, one oil control Iron
           
MAS 97 Piston, complete. MSS Standard size, for Alfin barrel        
MAS 97/2 Piston, complete. MSS +.020", for Alfin barrel          
MAS 97/3 Piston, complete. MSS +.040", Alfin barrel        
MAS 97/4 Piston, complete. 500cc Scrambler, Clubman, Standard size for Alfin barrel        
MAS 97/5 Piston, complete. Viper  Standard size, for Alfin barrel        
MAS 97/6 Piston, complete. Venom Standard size, for Alfin barrel        
MAS 97/7 Piston, complete. 500cc Scrambler, Clubman +.020", for Alfin barrel        
MAS 97/8 Piston, complete. 500cc Scrambler, Clubman +.040", for Alfin barrel        
MAS 97/9 Piston complete   Viper Scrambler, Clubman Standard size  for Alfin barrel        
MAS 97/10 Piston, complete. Viper +.020", for Alfin barrel        
MAS 97/11 Piston, complete. Viper +.040", for Alfin barrel        
MAS 97/12 Piston, complete. Venom +020", for Alfin barrel        
MAS 97/13 Piston, complete. Venom +.040", for Alfin barrel        
MAS 97/14 Piston, complete   Viper Scrambler, Clubman +020"  for Alfin barrel        
MAS 97/15 Piston, complete   Viper Scrambler, Clubman +.040" for Alfin barrel        
MAS 97/16 Piston, complete   Viper Scrambler, Clubman Standard size  for iron barrel        
MAS 97/17 Piston, complete   Viper Scrambler, Clubman +.020" for iron barrel        
MAS 97/18 Piston, complete   Viper Scrambler, Clubman +.040" for iron barrel        
MAS 97/19 Piston, complete. Viper standard size for iron barrel        
MAS 97/20 Piston, complete. Viper +.020" for iron barrel        
MAS 97/21 Piston, complete. Viper +.040" for iron barrel        
MAS 97/22 Piston, complete. MSS Standard size for iron barrel        
MAS 97/23 Piston, complete. MSS +.020" for iron barrel        
MAS 97/24 Piston, complete. MSS +.040" for iron barrel        
MAS 97/25 Piston, complete. Venom standard size for iron barrel        
MAS 97/26 Piston, complete. Venom +.020" for iron barrel for iron barrel        
MAS 97/27 Piston, complete. Venom +.040" for iron barrel for iron barrel        
MAS 97/28 Piston, complete. Scrambler, Clubman, Thruxton, Endurance  standard size for iron barrel        
MAS 97/29 Piston, complete. Scrambler, Clubman, Thruxton, Endurance   +.020" for iron barrel        
MAS 97/30 Piston, complete. Scrambler, Clubman, Thruxton, Endurance   +.040" for iron barrel        
           
T2/2 Piston, cast iron U, USS, 32        
RT 27 U Piston, aluminium U, USS, 32 Two Stroke Deflector Two compression Iron
RT 27/2 Piston 1930 GTP standard size Two Stroke Deflector Two compression Iron
RT 27/2/0 Piston 1930 GTP +1/2mm Two Stroke Deflector Two compression Iron
RT 27/3 Piston GTP standard size Two Stroke Deflector Two compression Iron
RT 27/3/0 Piston GTP +1/2 mm Two Stroke Deflector Two compression Iron
RT 27/3/1 Piston GTP +1 mm Two Stroke Deflector Two compression Iron