I'd say it usually is, but at high rpm there will be a point where the small outlet may not be able to exhaust the volume of the muffler. In my limited thought process, based on observation of a variety of racers on the road and dirt, best thing is to have the inlet and outlet at least the same size. As for the stock head pipe, odds are it's small to make for more low and mid range power. I know the aftermarket pipes for the 650 and 300 are larger than stock, so there's gotta be something to it. My pipe is actually an increasing taper head pipe connected to a reverse cone megaphone with what appears to be the same diameter or slightly larger opening, then connected to a glass packed muffler with a Supertrapp 4" silencer on the end. It pulls significantly stronger from 3500 up over stock. The guys at the shop where I used to sell bikes told me the felt the stock set up pulled stronger around 3000, but mine pulled away above that.

 

Gents, Ladies and Inbetweens,

I'm considering purchasing a KLX250 (Thai built and dirt version) for touring and general day to day use. Not sure if I have the right thread for this being new to this forum thing. I used to own an early 80's KLX250.


It appears there has been much discussion on the performance of the motorcycle over the past several years.


I am not interested in going 130-140km/hr flat out because there are few roads in the Lao PDR that would allow that anyway (let alone on a 250 dirt bike).

I am more interested in torque , throttle response and exhaust note (so I can be heard in traffic for safety reasons) ie. "Acceleration and noise to be basic" . If the top speed of a stock Thai KLX250 is 115km/hr (?) fine but I'd like to cruise at 90-100km/hr for the majority of my travel (at least I did that for thousands of kilometres on my old one) and be able to overtake/climb rapidly.

Can anyone tell me the Thai factory CPU mod part number (or an alternate eg. Power Commander), where best to buy it from (inThailand or online) and what is the best aftermarket full exhaust system I can buy in Thailand preferably or online?

Regards,

DB1Kinobe