Increase top speed
What does "Sorry, this thread has been deleted" mean exactly, and WHY?
Since I can type here, I'll assume its still "open", in some way.
If you REALLY want to put some effort into this, I'd say you are more likely to get payback (and less likely to break your bike) if you leave the engine alone and try and improve the aerodynamics.
Since standard naked bikes are so bad, significant improvements are possible with fairing, though the biggest have been achieved with a "feet-forward" configuration that won't be achievable with a CG125.
DIY fairing could be low-tech and quite cheap. For temporary, experimental attempts you could use skin-on-frame techniques, or papier mache. If you get something useful you could do a more permanent job in glassfibre. As a bonus you might get some weather protection, and maybe some crash protection too.
There are potential dangers, of course, like reduced steering lock, sidewinds, (see the controversy on "dustbin fairings") sharp edges, so you'd have to be careful, and regard it as an experiment, but if you survive your bike should be easily restorable to stock, and anything learned could be transferable to another bike,
Checkout Craig Vetters site
Or this streamlined Honda Innova. A crude prototype increased top speed by over 10mph, with more to follow (though this is a feet-forward design, and the focus is on mpg)
empty your pockets befor eyou get on the bike! loose some weight, go for a jog 3 times a week!!!
leave it alone man, just ride it and sell it on when done and buy a faster bike later. its really not worth the effort
How fast do you want a 125 to go? how much money have you got?!!! you could spend a few hundred quid having the cam reprofiled and maybe a re-jet, bigger carbs, high flow air filters blah blah blah, you could have the head skimmed blah blah blah.........but theres really no replacement for displacement on a road bike. bigger engine; more power to you.
Yeah - guess you could put in lighter push-rods, heavier springs, and a slightly harder opening cam, but sounds like a pretty fun project anyway.
Of course - there's always super-charging and nitrous
well time for an update,ive done 3000miles so far and made a few changes,first off i found another head off of a loncin off road bike with a 2mm larger inlet valve and a 1.5mm ex valve and fitted that along with an oil cooler,with this fitted it does 0-60 in about 7 secs,not sure of the top speed but the speedo and rev counter go off the clock (speedo goes up to 87mph) but i think about 95 at 12,000 revs,also forgot to say i ground 2mm off of the base circle of the cam,im running about 20 thou clearance on the valves and piston,not a lot but it seems ok up to yet!,well the problems so far are two blown head gaskets and a busted gearbox second motion shaft bearing!,firstly on the head gasket,well this was fixed by making one out of a piece of copper hot water cylinder and annealed and its been no trouble since,then on to the gearbox,this was a bit hairy as the bike locked up solid at about 65mph!,when the bearing broke up it let the shaft move sidwards about 3mm causing the kickstarter to engage,this shot the lever downwards at great speed denting the silencer,luckily it mist my leg which im sure it would have broken!!,the shaft was scrap as the bearing surface had bits of needle roller welded to it!,i ended up using one crankcase fron the loncin engine as the bearing was about 1mm bigger than the standard giantco crankcase,also the clutch end of the selector drum is supported by a needle roller as the original case it just runs in plain alloy,also the jet in the oilway that feeds the bearing has beed drilled out to 2mm to increase the oil supply to the bearing,was it all worth it?,well as the whole lot has cost me under £100 for all the mods and a few hours work i think so,it comes on cam at about 7500 rpm and pulls to 11000 plus,ive had a few old honda 250 twins from the 1970s and this would thrash them into the ground,so ive got a bike thats light goes like stink looks pretty standard and is fun to ride,so on the whole i think yes,the only downside is the fuel consumptiom,about 45mpg but you cant have it all ways lol.
Ha ha ha - I SOOO need to see that some day
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