the need for speed

[speedyspeedyboy]

http://en.wikipedia.org/wiki/%C2%A5 CNY & JPY shares the SAME currency sign!!!

Haha that explains it! I'll keep that site saved for now, have a proper look when I'm ready to make such as drastic change. Thanks.

[td_ref]

I have installed a 150cc bore kit, and top up the max speed to 110kph (GPS tested).
more cc is what you need.

[ZMC888]

Speedy, try reading up or finding some youtube videos where there are proven results, there may be something out there where someone has dyno tested a 125 and possibly made it more powerful by changing the fueling and proven it on a dyno, if you then replicated those procedures it might work for you. There is a particularly interesting video with some guys trying different pipes on a Harley connected to a dyno. Basically they found that by putting on the very popular 'drag pipes' which are straight-thru the bike lost some power and nearly all it's torque, then welding in a coin into the pipes to make a little restriction boosted the torque back up to nearly half a stock pipe.

I've never looked into changing a piston before, not sure about that one.

My logic would be that by increasing the airflow and fuel mix by a certain percentage you would need a muffler to be less restrictive by that amount too. At the end of the day don't worry about this stuff too much riding bikes is all about having fun and playing about with the way your bike runs can teach you a lot.

[speedyspeedyboy]

I have installed a 150cc bore kit, and top up the max speed to 110kph (GPS tested).
more cc is what you need.

Well that's rubbish because mine sits at 62mph, head down on flat 70mph, and I've had 85mph down a massive hill. People seem to always claim top ends are s bit lower that what they are.

And zmc888: you seem to love dynos. Ta for the advice though. Riding is and always will be the best bit about having a bike, but as I improve how I ride I want to spend some time and money and improve what my bikes capable of.

[td_ref]

Well that's rubbish because mine sits at 62mph, head down on flat 70mph, and I've had 85mph down a massive hill. People seem to always claim top ends are s bit lower that what they are.

If those figure read from speedometer, the actual speed should be 10-20% lower.

[speedyspeedyboy]

If those figure read from speedometer, the actual speed should be 10-20% lower.

If that's true it makes me sad. Why does it show at 10% increase?

[td_ref]

If that's true it makes me sad. Why does it show at 10% increase?

Welcome to the forum.

[that1guy]

One thing you can look at doing is porting the head. Along with re jeting or milling out the jets (For people like me who cannot get jet kits for my Chinese knock off carb). Proper carb adjustment will do wonders, in my experience. Always need to remember if your going to increase the airflow in and out of your engine you need to increase the amount of fuel. I've had rather good success with the mods I've done to my Baja DR125. Messing around with the sprockets is definitely something worth looking into, my bike from factory is geared extremely low. Figure in the range of 3.73ish final drive. I believe I had a 15 tooth on the front and a 56 on the rear, changed out the rear 56 tooth sprocket for a 43 did wonders for my top end (yes you do loose torque). However in my case I didn't loose a ton of low end power because the bike was geared extremely low anyways. Part of the reason the factory did this was to limit the top speed. You'll have to mess around with the sprockets to find out which setup works best for your driving conditions. Just remember not to go too low, otherwise you'll end up going slower in 5th gear than in 4th, and say goodbye to any torque lol.


Total mods I've done:

FMF slip on muffler
High Flow Air filter
Ported Intake and Exhaust (Maybe 1.25 to1.75mm at most)
High performance coil (Its hot orange, so it must be badass)
Performance CDI
Adjustment & Re jetted carb
Changed final drive gear from 3.73 to 2.86

[david.rmr125]

ive fitted a performance exhaust, swounds go and cars move out the way more the filtering tho trafic. i fitted cone air filter sounded faster but wasnt it just hit the rev limiter sooner than normal(rev counter brocken) so i fitted bigger jets (100) now it runs too rich and adjusting the card dosent seeem to work at all. so im going to just keep the exhaust now a fuck the rest off.

[speedyspeedyboy]

IMG_20130802_191247_898.jpg
Just an update.
So far I've fitted:
Yoshimurra rip off pit bike end can £35
16t front sprocket £9
Renthal fat bars £40

The cheap exhaust is sick. Not a perfect fit, but only 2mm out. Will get some wading soon. The sprocket is OK. I got it to reduce the strain on the beast; sitting at 7400rpm in 5th at 60mph, instead of 8500rpm. But there isn't enough power to back up the higher ratiod 5th gear, unless I'm going downhill or with my head down.