40mm cylinder or 44mm cylinder for my 49cc bike motor

[Mossy]

Ok so I need a low hole piston. so as long as I can get the rest of the measurements right I can still get a larger cylinder to replace the smaller stock one?

Not 100% sure... I would message Street Riderz a member on here and ask about it if he doesn't see this and chime in on it... He's our master builder on here that knows a lot about these motors

 

[SanTanfan]

Thanks.. I will try to contact them and I will follow up on how it goes. thanks for the help, just saved me some money by not buying the wrong part.

 

[Mossy]

@Street Ryderz

 

[Chainlube]

Check the cylinder stud spacing.

 

[Greg58]

If you have a 48cc engine with a 40mm bore there is only one piston available, you may see a 45mm bore listed on ebay but it won't fit, I tried it. If your engine looks like the one below and has 6mm head studs just choose who you want to buy from.

 

[Greg58]

Here’s another 48/50cc. The head stud spacing is 42mm.

 

[Freddy Snottgrass]

I got family in San Tan

 

[Greg58]

I found this which has every measurement correct, but now I am questioning if the piston will fit the rod.
This is what I found.

That cylinder is for upgrading a 66/69cc engine, I have a 69cc I upgraded to the 49mm iron sleeve top end.

 

[Greg58]

Here’s the 45mm cylinder with the 40mm on top, the bottom of the 40 mm cylinder actually goes into the 45, I haven’t measured it but it’s probably 44mm. You would have to align bore the cases to use the 45mm kit.

 

[DieselTech]

That cylinder is for upgrading a 66/69cc engine, I have a 69cc I upgraded to the 49mm iron sleeve top end.

What's your take on the 49mm bore cylinder kits? I love them! Makes ample power for me.