hi...i'm rudy from singapore. I juz bought an NSR 150cc SP. it's a thailand make.
Recently i've been trying very hard to find info on the internet on how to achieve the maximum power for my SP. i've down some portings to the bike n achieve a 200km/h speed on a gradually uphill road, within 1.5km. After that, i change the engine oil & new plugs. i've also added a "racing booster" (some electronic device that gives more current flow) in it. i set the rpm timer to 1100rpm. Everything else is still doing on stock.
However there's a problem i've face. I had to use the choke to start the bike frequently. Even to the extend of when i leave it after 3 hrs after i've ride the bike. Why?
I would also appreciate if experience nsr riders out there to give me tips n guidelines to improve the performance of my bike.Tanx mate!

The stock NSR150SP promises so much, but is a real let down if you ask me.

The engine's weak and the handling isn't worthy of the NSR badge.

All is not lost though as they are primarily designed to run in bangkok traffic at low to mid rpm on roads that the Western World farmers would consider "rough"!

Good tyres are a must. The stock Bridgstone rubber is pretty good. The suspension needs stiffening up. Try some porridge in the forks, that might get you a little damping! Seriously though, some 15W oil will probably work better than stock. can't do much to the rear (unadjustable) except preload.

But I guess that you're more interested in engine performance.

You say you've already done some porting. Did you mess with compression? any crankcase mods? carb? you're in Singapore so I bet you're using the stock pipe for fear of Police harassment!

The stock engine settings are pretty low spec. you need a bigger carb, a good pipe and the breathing through the engine needs attention all the way from start to finish. The intake especially is very restrictive at high rpm.

you can also lighten the flywheel and trim down the balance shaft (don't take it out).

Apparently there's also trick CDI's available, but I've only ever seen an HRC one and wasn't allowed to touch it.

Just keep fiddling with it. there's potential in that little rattler, but you'll have to get a little savage with the grinder.

yeah man..police harrassment!! the police even had Subaru WRX on the highway to bust speed demons on the roads.

Btw i was thinking of fitting an K&N air filter to replace the airbox. And fit chamber pipe to replace the stock ones. Is this enough to top the bike's performance?

Trimming down the balance shaft? Any hands-on details as how to do it?

hi... sryy to say this but if u wana go faster buy a BIGGER bike,i had a supped up rs125 with a 164cc big bore kit with longer gears and all sorts of gadgets to make it go faster when we finished with it was pussing 47bph......yup 47 bph.i send a great deal of money on this project only to be dissapointed apon ridding my nsr250R.if i was u i would get RId as soon as possible and dont waste any more money or time trying to make **** 150 go any faster.


bigger is better:)
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