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Post by brucie on Jan 14, 2021 21:08:06 GMT 1
Hi all just wondering if anybody knows what maximum you can bore a standard 125 cc cylinder out to on a mk 3 thanks
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Post by wonkywheel on Jan 15, 2021 20:27:32 GMT 1
About + 2.00mm, and in my opinion that’s pushing it.
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Post by 123 on Jan 15, 2021 21:49:31 GMT 1
+ 2.00 in my opinion aswell
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Post by brucie on Jan 15, 2021 22:35:55 GMT 1
About + 2.00mm, and in my opinion that’s pushing it. Thanks for that roughly what cc would that be cheers |
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Post by pedheadfred on Jan 15, 2021 23:27:04 GMT 1
Scooter tuning calculator makes it 132cc
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Post by brucie on Jan 16, 2021 0:03:25 GMT 1
Thanks for the replys i imagined it would be more but now I know thanks
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Post by wonkywheel on Jan 16, 2021 0:04:40 GMT 1
About + 2.00mm, and in my opinion that’s pushing it. Thanks for that roughly what cc would that be cheers Standard piston 56mm =123cc +2.00mm = 125cc Not unless, I’m told otherwise... |
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Post by pedheadfred on Jan 16, 2021 0:28:16 GMT 1
A std MK3 rd125lc is 123 cc according to all info I can find 🤔
Go on scooterhelp.com/tuning/defs.cc.html a STD mk 3 rd125lc is if Iam correct 50mm stroke 56mm bore.
Which on the above site equates to 123.15cc
So if you increase by the said 2mm it equates to 132.1cc
Another free engine cc calculator I use is this one.
Performance trends.com/calculators/engine Displacement calculator
Just check it out for yourselves 🕵️, Iam only trying to help 😜
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Post by pedheadfred on Jan 16, 2021 20:15:21 GMT 1
Thanks for that roughly what cc would that be cheers Standard piston 56mm =123cc +2.00mm = 125cc Not unless, I’m told otherwise... If stroke is 50mm and bore is 56 then if cylinder was bored out to 0.5mm over size. Then it would be 125.36 CC Punch in the figures in the cc calculator on these sites it will show you were my figures came from its do easy to use, (even I can use it) 🕵️👍 |
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Post by 17again on Jan 18, 2021 18:33:25 GMT 1
i read years ago they did 140cc piston kits for them from japan.
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Post by arrow on Jan 18, 2021 18:48:15 GMT 1
I've modified an oil pump for a 180cc kit for these bikes.
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Post by 17again on Jan 18, 2021 20:28:06 GMT 1
I've modified an oil pump for a 180cc kit for these bikes. I didn’t and it locked the back wheel up. Shame I was to young to think to premix it. |
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Post by brucie on Jan 18, 2021 21:14:26 GMT 1
There's a big bore cylinder on eBay now but you need to modify the clutch as far as I'm aware the 140 cc would be great but never even seen one
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Post by pedheadfred on Jan 19, 2021 0:41:30 GMT 1
MK1 125lc there were BB kits Autisa 66mm piston 170 kit but never seen anything for the ypvs engine.
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Post by Norbo on Feb 10, 2021 10:08:11 GMT 1
The biggest one you can do it actually 3mm over standard but the pistons you use dont have windows in the back they are a crank ported piston so have a cut out in the bottom of the skirt . This means they dont rev quit as hi but have more torque lower down
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Post by 17again on Feb 10, 2021 18:54:27 GMT 1
The biggest one you can do it actually 3mm over standard but the pistons you use dont have windows in the back they are a crank ported piston so have a cut out in the bottom of the skirt . This means they dont rev quit as hi but have more torque lower down i think i had one of those once, it only had one piston ring and a had moon shape skirt. i also had a 170 kit back in the day for my mk1. |
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Post by Norbo on Feb 15, 2021 11:52:09 GMT 1
no they are still a twin ring piston . i use them all the time in lc barrels
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