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Alternative 2 Stroke for Part 103!

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Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,797
Location
AMES, IA USA
Alternative 2 Stroke for Part 103! I picked up a Crank years ago for $60. I paid $67 for this Case & Cylinder/Head combo off eBay. The Skidoo TUNDRA 250 Type 253 is rated 22hp@6000rpm! (72mm x 61mm) 248.36cc / 7cc = 35.48 hp at 6500rpm can be madeusing a Tuned Pipe. Can be Big Bored up to (82mm 61mm) 322.14cc!

To make 28hp x 7cc = 196cc.
To make 30hp x 7cc = 210cc.
To make 32hp x 7cc = 224cc.
To make 34hp x 7cc = 238cc. Overbore (72.75mm x 61mm) 253.56cc
To make 36hp x 7cc = 252cc. Overbore (73mm x 61mm) 255.31cc
To make 38hp x 7cc = 266cc. Overbore (74mm x 61mm) 262.35cc

Back Bearing Case OD 62..8mm.

Front Bearing Case 62.3mm.

Case/Cylinder Bolt Pattern 108mm. Could be Big Bored to 82mm.

V Bolt Pattern. Max 60mm across. 76mm Diagnal. 10mm Bolts.

Exhaust Port 40mm ID. 50mm OD.

Exhaust Port 37.8mm wide. 22.2mm high.
Intake Port 24.8mm High. 42.8mm Wide.

11.824 lbs for the Case & Cylinder & Head. I have to Weigh the Crank.

72mm Bore x 67% = 48.24mm is what the Ports can be Widened too. My 335 Single is Intake is 26.5mm x 47mm and my 340 TnT 29mm x 47mm.
 

Attachments

  • My 250 Type 253 Bottom.jpg
    My 250 Type 253 Bottom.jpg
    211.4 KB
  • My 250 Type 253 Carb Side.jpg
    My 250 Type 253 Carb Side.jpg
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  • My 250 Type 253 Exhaust Side.jpg
    My 250 Type 253 Exhaust Side.jpg
    245.9 KB
  • My 250 Type 253 Front PTO Side.jpg
    My 250 Type 253 Front PTO Side.jpg
    213.9 KB
  • My 250 Type 253 Full Back Side.jpg
    My 250 Type 253 Full Back Side.jpg
    256.9 KB
  • My 250 Type 253 Info.txt
    413 bytes
  • My 250 Type 253 Top.jpg
    My 250 Type 253 Top.jpg
    190.7 KB
  • TUNDRA 250 TYPE 253 22hp@6000rpm.jpg
    TUNDRA 250 TYPE 253 [email protected]
    81.5 KB
  • My 250 Type 253 Back.jpg
    My 250 Type 253 Back.jpg
    223.9 KB
Last edited:
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