What is the best exhaust system for a honda ls 125 1998 model?

unless you want to spend lots of money chasing your tail for little result , the best place to start is a bike shop that specializes in power or performance and get as much spot on information first
and improvement has to be planned and not guessed
start with a dyno test to see where you are at first
This is the datum line upon which to gauge success with each modification you do
most bikes improve with a modified exhaust system but you need to know how much you gain over the datum line as feeling better is not always right and could be costly in other areas
so be advised that specialist shops who understand what you want to achieve , how much you are prepared to spend and can show proof of the results for each stage of development is the only way to go

The bascs are - For your NSR - Remove the intake restrictor, drill some holes in the exhaust, and find a replacement jet for the carb.
Sounds simple but is not. Had a bunch of stuff for you to read but post would not go (before). Search Google "2001 Honda NSR 125 R" to find specific info and forums for your bike, and dont experiment unless you can afford to.

The below are improvements over the years. One thing to remember that a HUGE % of the energy the rider puts into moving forward is used to overcome wind resistance.

In terms of motion....

Lighter overall. Lighter bikes overall, lighter wheels - easier to spin up and keep rolling.

More efficent bearings all around/ wheels cranks, etc.

Better design of frames/bars, etc. Positions the rider better on the bike to convert his energy into forward motion Also - better positions the rider on the bike to cut the wind better - lower rider resistance.

better tires, skinner tires - Less rolling restiance -

Hi,

I suggest to check wether the carburator has a restriction in the holder
check if the clapets (between carb and cilincer) has a restriction
check if the exhaust has a restriction.

But overall: a race-exhaust, a tecnician who personalizes the carb to the local wether conditions by adjusting the jet, an eventually needed unrestriced cdi will improve bigtime.

greetings from a big 2s fan.

Olivier.

Many factors go into the style of a bike.
Changing the exhaust is a major issue in regards to position of the current hardware and wiring. Designers at the time the bike is being developed determine position, size heat shielding etc. Local codes, restrictions and generally what sells today. Once the fabrication starts on a specific model it is rare that major changes like the exhaust system are allowed.

That is what after market exhaust pipes are for.
I for instance can't stand the one large big pipe.
Dual pipes on each side have a better sound and seem to balance the bike.
But that is only my opinion and everyone has one. :)

Keep in mind, There is no dumb question. Only the one not asked. :)
Have a great day!

Need to know the year of the bike,but you may find that your powervalve is not working or lifting up to open the exhaust port fully.Does it rev cleanly otherwise?You could also have a carb issue if it doesn't.

I also find that if the bike has a high mileage the carbon build up in the expansion chamber will be too much and then it will need to be burnt out...this can improve the performance significantly.

Please leave some positive feedback for me if this solves your problem and get back to me if you need to.

Thanks

Yoshimura's stuff is the best under the sun. Be sure to order the TEC kit if you get it. It gives you two sound inserts. The smallest makes the bike as quiet as stock. Best fit and finish there is as well!

must the exhaust be specific to the model is there no way to take an exhaust made for a similar scoot and fit it to the scarabeo? What is your goal? The scooter exhausts offered by Leo Vince and Malossi aren't actual performance systems. People use them because they want to customize the scoot or get more of a growl sound while also passing emission inspections. Most people in the USA never have an emissions inspection on their scooters and are thus free to bolt on any exhaust they choose. If you are looking for performance you need an aftermarket free-flow system like those used for off-road bikes and your only limitation is how loud of an exhaust you are willing to accept. There are plenty of aftermarket exhausts for pit bikes and small dirt bikes that should bolt on to the S100-4T. Personally I would start by looking at mods people have done on the Honda XR70 since it's about the same size engine and uses the same 20mm Keihin carburetor. Of course if you bolt-on an aftemarket free-flow dirt-bike exhaust you will need to replace the existing restrictive airbox with a free-flow K&N unit and either add larger jets to the existing carburetor or switch to the high-flow 20mm PE Keihin or the 24mm Keihin. Either way, the muffler is the easy part it's getting the fuel/air mix right and that's all carburetor work. ,,,