am i right by sayin that if i get a 180 bore for my 125 runner would i need to mod the engine casings or nefin.? thanks for any comments
Yeh you need to get the casing lathed speaking of which does any1 know of anywhere that can do it and for how much?
i didnt think you have to.. im sure u can just stick a 180 bore on a 125... but its best to just get a 172 as ppl with 180's tend to get a 172 cos theyre better ported etc...
I dont bout it for sure but every1 says the 172 runs better on a 125 than it does on a 180 cos it suits the 125 more
Hmm i dunno.... i wouldnt stick a 172 or 180 on a 125 until i have a bigger carb and maybe a sports exhaust... other wise you'll forever have problems cos the engine wont get enough fuel/air.... You can just stick a 172 or 180 on a 125 engine, and it will be MUCH quicker, but it would benefit from a bigger carb, and even a 180 variator..
yeh true but you wouldnt have problems running a 172 wiv standard exhaust and carb as long as you set it up right then it would be fine
fuck carbs my quickest set up for power wheelies was a 172 kit on its own and an exhaust.... and carbs just drink more petrol and another thing for theifs to nick in my opinion....
I did this to my old runner 125. The bottom of the barrel needs to be turned (or filed carefully if your on the cheap) and the stud holes drilled out a little. It will not bolt straight on. The reason for using 125 cases is keeping the crankcase compression as high as possible (dont want to go trying to flow/match milled casings when theres chunks already gone) When i did mine i put the 180 jets into the standard carb (which is a 20.5 on both 125 and 180 anyway), 180 variator, 180 polini belt, 180 clutch (just for the cooling fans), 180 gearing and a scorpion. Pulled 90 clock very easily and getting there was quick too. Never had any reliabilty issues with the engine, Though the new owner has given it back to me to do the whole 172 on it.
i will mod a 180 to fit a 125 case if needed, will lay the malossi 172 port map onto it aswell if you want a decent performing 180 (or an iron sleeved 172 as the case may be)
Yea but if we're talking about setting up a 172 and having it all right, and to its best performance, a bigger carb is necessary in my opinion.
my best setup for wheelys was a m8's bike with a 30mm carb pm and a whole load of ground goodies. power wheelys above 60mph anyone?
i heard 180 cranks are different to125 but there not definatly, i know 180 barrels will definatly not fit on a 125 engine ( been sold ''180'' engines which turnt out to be 125) i think the reason people like to put 172 in 180s is due to the carbs having bigger jets and better gears etc.
the replacment crank offerd by piaggio is the same on ether 125 or 180 yet the 180 uses a crank with slightly larger webs to correct the compression loss from the larger case. 172 on a 180 is simply because people have a 180 engine and cant be assed changing all the bits into a decent case
