Big bore kit will it work??? Any input??

[livingoodnathan]

So I've been toying with the idea of getting a bigger top end for my bike. There is a ton of kits out there And after a lot of research I've found this one ( pictures below). I have to do some measuring and fine details sorted but i think it will work what y'all think. It's a 50 mm bore and I believe the outside diameter of the skirt is right at 56mm (which i.could shave a couple mm off if need be. Only thing is I have yet to find out anything saying what the stroke is. Are there any bore kits out there that are known to work for sure without much modifying. Looking for close to a bolt on application as possible if I have to change the rod so be it but i would like to find something that woukd work with my 47mm stroke. In need of a new project. My engine is a pk80 race engine built by Fred at cr machine.

 

[Frogslayer]

Changing the rod will keep the same stroke but move that strokes height higher or lower. To achieve different strokes you'll have modify the crankshaft or possibly replace it with a different one.

 

[Will'smotobikes19]

There is rip-off Robert who sells big bore stuff. Mzmiami has a 48mm sleeved cylinder on eBay. With mods a 54mm ms660 jug will work. Actually soon there will be a bigger bore version of the CG from zeda Zillin technologies.

 

[Frogslayer]

There's no replacement for displacement. (Stole that from Gran Turismo)

 

[livingoodnathan]

There is rip-off Robert who sells big bore stuff. Mzmiami has a 48mm sleeved cylinder on eBay. With mods a 54mm ms660 jug will work. Actually soon there will be a bigger bore version of the CG from zeda Zillin technologies.

Yeah ive researched the 660 and it is too much modification I'm willing to take on right now i dont want to go weeks probably months with no bike. I was hoping Zeda was going to start selling the big bore top ends but ive seen more than a few people exposing their work for what it really is and to be honest from watching a few of there videos I think they are people trying to get rich off people from selling them s**t parts and motors and keeping all their real mods to themselves. I've just seen too many things that came from them that was s**t. On top of that they bashed my boy Fred/cr machine in one of there videos and I know he does good work. I wouldn't buy a motor from anyone else. Idk just trying to find something easier than the 660 mod.

 

[Will'smotobikes19]

There’s a clone of the ax100 motor which was made by Suzuki maybe that would work. If you want more power. I think it has kickstart and gears.

 

[livingoodnathan]

Changing the rod will keep the same stroke but move that strokes height higher or lower. To achieve different strokes you'll have modify the crankshaft or possibly replace it with a different one.

So what would the stroke be for this kit? I can't find anything with that info. There is a bunch of websites selling this kit but they all say "works with stock stroke" and I can't find anything that says what "stock stroke" is for the scooter. I've got to do some more research just wanted some input and to see if there are any proven kits out there.

 

[Will'smotobikes19]

Stock is 38mm upgraded motors are 40mm or known as triple 40’s. I got a pk80 too it’s 40mm 47 is the bore.

 

[Frogslayer]

Took a little searching but i found your solution!

 

[livingoodnathan]

There’s a clone of the ax100 motor which was made by Suzuki maybe that would work. If you want more power. I think it has kickstart and gears.

Yeah? I've also found that a 1990 yamaha rx100 has a cylinder that looks close. There only sold in India. Check them out.