What does a bore kit do? And can a 125cc engine have one?

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ThisGuy

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What does a bore kit do? And can a 125cc engine have one?
 
the bore is the engines' barrel, or cylinder.
the kit's usually come with a new standard sized cylinder, new piston to suit, new rings, gudgeon pin, gudgeon bearing, and related gaskets.


when your engine is worn out, you can have the engine cylinder bored to suit an oversize piston/rings,
or-
you can use the new standard bore kits to replace a worn out or damaged cylinder, this is basically a top end rebuild.

or sometimes, f you can fit a bigger bore to your motor, then this can increase the engine size,

eg fitting a bigger bore to some 125s, will make it become a 138/140cc engine.
it depends if you can get one that has the same gudgeon pin sizes, so the new bigger piston will still fit onto your conrod, and also depends on whether the cylinder skirt of the big bore will fit inside your casing.
otherwise case machining is required to make it fit
another example- fitting a big bore to a YX160 can make the engine a 184cc engine.
 
the bore is the engines' barrel, or cylinder.
the kit's usually come with a new standard sized cylinder, new piston to suit, new rings, gudgeon pin, gudgeon bearing, and related gaskets.


when your engine is worn out, you can have the engine cylinder bored to suit an oversize piston/rings,
or-
you can use the new standard bore kits to replace a worn out or damaged cylinder, this is basically a top end rebuild.

or sometimes, f you can fit a bigger bore to your motor, then this can increase the engine size,

eg fitting a bigger bore to some 125s, will make it become a 138/140cc engine.
it depends if you can get one that has the same gudgeon pin sizes, so the new bigger piston will still fit onto your conrod, and also depends on whether the cylinder skirt of the big bore will fit inside your casing.
otherwise case machining is required to make it fit
another example- fitting a big bore to a YX160 can make the engine a 184cc engine.
What would I have to get to bore my 125? Everywhere I look I see a 114cc or 88cc bore kit
 
yeah, the kit linked above, is a big bore/stroker kit
so will increase the length of stroke at the same time.
this requires a full engine pull down, cases split, gearbox apart, and a crank swap etc etc
and before you buy a bore or bore/stroker kit, you might want to consider your current engines wear.
thing like shift drum fork, clutch, kickstart parts/gears and gearbox components might be worn out, and require replacing at the same time
so it might end up expensive, or just as much as a new engine?

sometimes it may be easier just fitting a new bigger engine,
http://tboltusa.com/store/piranha-140cc-enginebr-fits-pit-bikes-and-other-minis-p-660.html
http://tboltusa.com/store/pitster-pro-155-engine-brfits-pit-bikes-and-other-minis-p-522.html
http://tboltusa.com/store/pitster-pro-155-engine-brfits-pit-bikes-and-other-minis-p-522.html

if you are considering one off the latter engines them it might pay to look at this one ?
they are priced very good atm
http://tboltusa.com/store/daytona-engines-daytona-190cc-engine-c-114_120_534.html
 
wow, the 190 is pretty cheap there! e-bay is sellin the for 1490? or 1390? still thats the cheapest i've seen 'em
 
"import tax, get one sent to a usa friend then sent as a gift" quoted from a unknown persons from the international waters...
 

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