TW200 Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hi I just bought a 2002 TW 125, and I'm wondering is there any cheap mods that I can get for starters.
 

·
Registered
Joined
·
156 Posts
I would suggest the following(not all are mods):
1.A good service if it's neglected+[new air filter,clean carb].
2.Properly inflate tires.
3.Bigger rear spocket(will increase fuel consumption and reduce top speed probably).
4.Jetting
5.Exhaust+Jetting(probably not cheap)
 

·
Super Moderator
Joined
·
4,851 Posts
Disconnect the exhaust from the cylinder head, and look for a washer inside the exhaust restricting flow

This is about all you can do with the 125 without taking the top end of the engine off and modifying near enough everything

If there is no washer in said location – then it is what it is – get used to it …….

Welcome to the board ….
 

·
Registered
Joined
·
1,462 Posts
If you have a kickstarter remove the battery. If not a smaller lighter battery will reduce a little weight. Not cheap but a good plan in the long run. I hear aftermarket mufflers can give a small increase to performance and even weigh a little less, but costly.
 

·
Registered
Joined
·
165 Posts
While it's fun to say "a reduction in weight will increase horsepower" that's not actually true. Horsepower is an engine derived calculation. Increases in horsepower can only really come from direct changes to the mighty TW engine, which may include opening up the airbox/re-jetting or even modifying the exhaust. Or..nitrous!! Reductions in weight and changes in gearing, rider ergos can improve handling, throttle response time and tractability. IMHO-these are the changes that really impact the attitude of the TW and my enjoyment of it.
 

·
Super Moderator
Joined
·
4,851 Posts
The TW125 in the UK market is aimed at “learner drivers” – so if the bike is capable of too much horse power, the bike becomes unlawful to ride on “L” plates here in the UK

There are two primary ways of restricting the horses on the 125 – one is the introduction of a washer inside the exhaust to restrict flow – the other is more likely in the EU, and relies on the speedo cutting out the CDI

I am unaware of any other methods – if you have input, it would be appreciated

“Nitrous” – losing weight etc – is all well and good in humour. Just remember, you are encouraging a learner rider to go faster – we all know how that usually turns out

The OP asked an honest question, which deserves an honest answer – and not one that is going to get him killed

An over exaggeration perhaps, but you know what I mean ……. ;)
 

·
Registered
Joined
·
1,927 Posts
While it's fun to say "a reduction in weight will increase horsepower" that's not actually true. Horsepower is an engine derived calculation. Increases in horsepower can only really come from direct changes to the might TW engine, which may include opening up the airbox/re-jetting or even modifying the exhaust. Or..nitrous!! Reductions in weight and changes in gearing, rider ergos can improve handling, throttle response time and tractability. IMHO-these are the changes that really impact the attitude of the TW and my enjoyment of it.
Yeah, "reduced weight doesn't improve horsepower" but it surely improves the power-to-weight ratio, thereby improving acceleration.
You might call it "free or synthetic" HP!

That's why builders of (most) racing & performance vehicles reduce weight as much as possible...
 

·
Registered
Joined
·
156 Posts
The TW125 in the UK market is aimed at “learner drivers” – so if the bike is capable of too much horse power, the bike becomes unlawful to ride on “L” plates here in the UK

There are two primary ways of restricting the horses on the 125 – one is the introduction of a washer inside the exhaust to restrict flow – the other is more likely in the EU, and relies on the speedo cutting out the CDI

I am unaware of any other methods – if you have input, it would be appreciated
I was just surprised by the fact that a 4t engine is restricted with an exhaust washer/restrictor, I thought only 2 strokes were restricted this way.
I have seen the "L" plates in some videos, but I assumed that the bikes were just A1 license compliant(up to 125cc and 15 hp,I doubt the tw125 is more as the tw200 is 16HP as far as I know).
 

·
Registered
Joined
·
19,401 Posts
Serious reliable power increases can be had depending on your budget but none are technically cheap. Bigger valves, higher displacement cylinders and pistons, with or with out high compression pistons, stronger valve springs, etc all can increase ability of engine to pump more air/fuel mix and thus more peak horsepower. Then a better exhuast system reap some benefits. A pumper carb can help a stock or modified engine accelerate quicker. All demand time and money though.
 

·
Registered
Joined
·
721 Posts
Serious reliable power increases can be had depending on your budget but none are technically cheap. Bigger valves, higher displacement cylinders and pistons, with or with out high compression pistons, stronger valve springs, etc all can increase ability of engine to pump more air/fuel mix and thus more peak horsepower. Then a better exhuast system reap some benefits. A pumper carb can help a stock or modified engine accelerate quicker. All demand time and money though.
Yeah I’m still surprised there are no pumper kits anywhere. I’d try one for sure. I’m not a fan of the current glueing the intake hack.
 

·
Super Moderator
Joined
·
4,851 Posts
I was just surprised by the fact that a 4t engine is restricted with an exhaust washer/restrictor, I thought only 2 strokes were restricted this way.
I have seen the "L" plates in some videos, but I assumed that the bikes were just A1 license compliant(up to 125cc and 15 hp,I doubt the tw125 is more as the tw200 is 16HP as far as I know).
No idea whether it’s to restrict speed on full chat rather than BHP, but it’s the way Yamaha approaches the issue for many countries with varying regulations – if you think that’s weird, try the speedo option. The needle hits 60, and it cuts power to the CDI …..
 

·
Registered
Joined
·
439 Posts
1 - 19 of 19 Posts
Top