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piston install direction question

   
Old Mar 17, 2014 | 08:10 PM
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Default piston install direction question
Wondering if fuelmoto CP 10.25 pistons have a front or rear orientation. I know the larger valve reliefs need to be inward facing and are the intake reliefs. Never saw any front or rear arrows like stock slugs and nothing in the cp instructions from what I can see. Anyone?
 
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Old Mar 17, 2014 | 08:18 PM
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You are correct. The larger reliefs are for the intake valves. So they go inward towards the carb/throttle body.
 
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Old Mar 17, 2014 | 08:22 PM
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Originally Posted by WI Bob
You are correct. The larger reliefs are for the intake valves. So they go inward towards the carb/throttle body.
So each piston is interchangeable front to rear as long as the large valve reliefs are facing center/each other, right? The pin bores are center and not offset as in the,stock ones. Correct? Just want to be sure.
 
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Old Mar 17, 2014 | 10:12 PM
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A quick call to FM will answer this.
 
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Old Mar 17, 2014 | 10:27 PM
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No difference between them, the can go in either hole.
 
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Old Mar 18, 2014 | 12:37 AM
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The pistons are probably close to being identical. It is up to the machinist who bores your jugs to label the piston/jug matching.
 
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Old Mar 18, 2014 | 11:29 AM
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FYI - I talked with Keith @ FM today just to be sure. CP 10.25 FuelMoto pistons are interchangable front to rear. Obviously the larger valve reliefs are for the larger intake side valves and must be positioned as such. Larger reliefs facing each other toward the center of the motor.
 
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Old Mar 18, 2014 | 11:49 AM
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Originally Posted by 12hdrk
FYI - I talked with Keith @ FM today just to be sure. CP 10.25 FuelMoto pistons are interchangable front to rear. Obviously the larger valve reliefs are for the larger intake side valves and must be positioned as such. Larger reliefs facing each other toward the center of the motor.
They are the only people I'd trust to answer this question. You can see the different interpretations random internet answers are based upon.
 
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Old Mar 18, 2014 | 05:31 PM
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Originally Posted by 12hdrk
FYI - I talked with Keith @ FM today just to be sure. CP 10.25 FuelMoto pistons are interchangable front to rear. Obviously the larger valve reliefs are for the larger intake side valves and must be positioned as such. Larger reliefs facing each other toward the center of the motor.
In addition the the intake valve reliefs there is also a cutout on the bottom of the piston skirt for connecting rod clearance that goes to the center also.

Just thought I would throw that out there.
 
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