Author Topic: piston to cylinder clearance for a cb125j  (Read 873 times)

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Offline mazingerzeca

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piston to cylinder clearance for a cb125j
« on: June 12, 2008, 09:28:29 AM »
Hello all.
Do you know which should be the piston to cylinder clearance for a Honda cb125j? The Haynes manual says that standard cylinder bore internal diameter is 56.50 - 56.51 mm (2.2244 - 2.2247 in) and piston standard diameter is 56.46 - 56.48. This is going to be 2nd rebore, so the piston will be 56.96+-.

fuzzybutt

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Re: piston to cylinder clearance for a cb125j
« Reply #1 on: June 14, 2008, 05:15:46 PM »
i would guess around .04mm. piston manufacturer of the replacement piston is the best place to ask though.

Offline crazypj

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Re: piston to cylinder clearance for a cb125j
« Reply #2 on: June 16, 2008, 09:00:32 AM »
About one and a half thou (0.0015") is good (+/- 0.0002")
 If its going to ge a lot of 10.500~11,000rpm, go closer to 0.002"
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Offline mazingerzeca

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Re: piston to cylinder clearance for a cb125j
« Reply #3 on: June 16, 2008, 10:20:21 AM »
Thanks for the replies.
The manufacturer of the piston is Honda.
Well, I will go somewhere between these measures.

Offline bryanj

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Re: piston to cylinder clearance for a cb125j
« Reply #4 on: June 17, 2008, 05:56:47 PM »
If its 2nd over add 0.5mm to standard sizes and bore to that
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