[Performance air filters. Are they worth it?]

they're never worth it, unless you're racing and at the top of your game!

larger bikes have so much power and torque, and performance, that putting race and performance parts on them for non competitive use is pretty pointless.

Smaller capacity bikes such as 125 etc, don't gain enough from these kind of mods to make them worth while at all.

Racing however, yeah they will help get more power, but it's gonna save you maybe 1/100th second per lap at the most, but then again, unless you are exceptionally good, you will probably lose this time in one corner.

So, road vehicles, useless. Race machines, more time to be had, for free, by improving your own abilities.

[Would there be interest in fibre glass parts/vinyl wrapping?]

To be honest, the market is tiny, and difficult to make work on a large scale.

I build carbon fibre components, the problem is, that as mine are hand made, and in smaller quantities it's extremely difficult to compete with companies that specialise in this kind of thing.

Stuff like huggers, chain guards and mudguards etc I can beat on price. But when I priced up doing track bodywork for a friend, it was cheaper for him to buy it from a large company.

I only really custom parts now, as it's the only market left.

[Starting Problem]

Did you charge the new battery fully before you fitted it to the bike?

[Virago XV125 regulator/rectifier]

Glad you have traced it back now, as others have said, unplug, unbolt and reverse it.

And no, it shouldn't be covered in any kind of powder!

[Problems starting xv125 Virago]

Follow this guide, this will test the full charging system with nothing more than a multimeter.

Follow the steps, and it will it narrow down your exact fault.

http://www.electrosport.com/media/pdf/fault-finding-diagram.pdf

[Problems starting xv125 Virago]

buy new rec, unplug old one, plug new one in.

I'm off to bed now as work again in the morning. I will post up detailed reg/rec test sequence tomorrow

[Problems starting xv125 Virago]

If you're hearing an electrical sound but it's not turning over then it's likely the battery is flat.

If it cut out while riding, it's like the reg/rec isn't charging the battery. Additionally, batteries don't like the cold, and will die quickly if not left on a maintained charger through unused periods in winter,.

[What bike have i got?]

To be 100% sure, you could just call Yamaha up, and give them the frame number, they will tell you what the model is within seconds.

[brake pads - OEM or aftermarket?]

already replied to other thread!

[brake pads - which do you suggest]

Go with EBC HH mine are fine, after 2 trackdays, and about 1000miles, and are still fine!

Unless you're a racer, you need no more power. Make sure you copper grease the rear of the pads to stop them squeeling though

[ITS F**KING COLD!!!!!]

haha, cold you say?! I was at Oulton Park for a trackday at 7:30am on 3rd! That was chilly, especially in leathers at 100+

[Which is better/faster?]

No reason for me to echo what all others have said about it being the better rider, that is obviously true. Out of curiosity here are some figures.

YBR 10:1 Compression

YZF 11.2:1 Compression

YBR 7.5kW @ 7800

YZF 11kW @ 9000

YBR 9.6NM @ 6000

YZF 12.2NM @ 8000

Can see here the YZF is slightly more powerful, but will need to be worked harder to keep the revs higher for the performance.

YBR 5speed

YZF 6speed

This will help with keeping it revvy, as gearing will be short, but may be a hassle town riding.

Caster and Trail both are shorter on the YZF giving quicker steering, and wider tyres giving it higher lean angles, and is likely to also have larger ground clearance for faster corner speeds.

YBR is 125kg

YZF is 138kg

So you already have 13kg weight advantage.

All being equal the YZF-125R will probably be slightly quicker, but biggest difference will be the handling, unfortunately it is down to the skill of the rider to extract the most from a machines handling.

[Motorcycle Live @ the NEC]

I'm working Tuesday, so it's looking like I'll be down on Wednesday. Really wanting a go of the enduro, motorcross and trials riding!

[air box removal]

little problem ....iv got 3 kids under 4 years old the youngest being only 2 weeks old so library is a no go, but internet on the other hand, i can use that anytime iv had a read on 4 stroke tuning and come to the conclusion that unless you have a small fortune to waste then there is no point trying to tune the 125cc 4 stroke. but im not trying to tune so to say, im just replacing the original airbox cause it wont fit.

and a hypercharger? .....no point id have to put a new engine in every week

If you're not attempting to get it running as well as possible with a smaller airbox, then just make something fit and play about with it till it runs how you're happy with. It all depends what you're aiming for to be honest. I found a lot of internet articles often came with a lot of garbage in them too.

[air box removal]

Best thing to do is get down to a library and take a good old fashioned, no bullshit book out about 4 stroke engine tuning.

[air box removal]

0.125litres x 1.3 = 0.1625litres so, 162.5cc of filtered air.

As above, it's to do with providing smooth air flow, and having readily accesible air for the engine to take on quick throttle openings, this is the job of the airbox (plus protecting it from heat), adjusting the dimensions and volume can affect how the engine runs.

130% isn't a hard and fast rule, but is a popular starting point for air intake systems in motorsports, generally rallying where a lot of people still run airboxes, there's a lot of research around the K&N site about it, if you read around.

[air box removal]

you cant just put a filter on the end of the carb, as the little 125 engine just wont work (this was my original point) the air needs to be sucked in by the engine so the vacume can suck the fuel from the carb, mix with the air then go into the chamber. the dragstar 125 uses a special pipe to control airflow into the engine where-as the cbr uses a box, both restrict air flow in some way. iv been doing some research into it and have come up with a new setup.

im going to use a silicone u bend with a cone air filter on the end, now to restrict the airflow im going to have to think of a way to put a sort of butterfly valve in there (similar to the throttle valve on the carb) then i can have a play with different setups to find the best for the engine. might even make it spring loaded then it would free up airflow when the engine needs it. in theory it should work and all id need to do is find the right tension spring and put a slightly bigger main jet in. but il order the parts, have a play and post the results

For optimum throttle response, you should have 130% of the engine's capacity of filtered air between the filter and the butterfly.

[how to estimate top speed]

Was bored so wrote a quick Java Application for this. Not sure how to add an attachment on this forum, so here's the source code.

// Sprocket calculator


class Sprockets

{

        public static void main (String[] args)

        {


        // Check correct syntax at runtime

        if (args.length != 5)

                {

                System.out.println("Syntax: java Sprockets OrigRear OrigFront NewRear NewFront TopSpeed");

                return;

                }


        //Set Variables and calculations

        double OrigRear = Double.parseDouble(args [0]);

        double OrigFront = Double.parseDouble(args [1]);

        double NewRear = Double.parseDouble(args [2]);

        double NewFront = Double.parseDouble(args [3]);

        double TopSpeed = Double.parseDouble(args [4]);

        double OrigRatio = OrigRear / OrigFront;

        double NewRatio = NewRear / NewFront;

        double n = OrigRatio - NewRatio;

        double u = OrigRatio / TopSpeed;

        double p = OrigRatio + n;

        double NewTopSpeed = p / u;

        int RoundedTopSpeed = (int)NewTopSpeed;


        //Print Result

        System.out.println ("New top speed is " + RoundedTopSpeed + " MPH.");

        }

}

[/code]


You'll need to copy and paste to a text editor save it as a *.java file and then compile and run it.  It will work on all formats.


If anybody wants the actual executable file for this, let me know and I'll email it over, Java Runtime Enviroment is needed for it though.

[Motorcycle Live @ the NEC]

I think I'm going to be there either on the Tuesday or Wednesday too. Not sure if I'm up on the bike or not though yet.

[2002 R6 Front Pads]

So, I took the pads out of the R6 earlier, to grease up the slide pin and piston faces etc before winter as I use it year round.

The front pads are looking quite a bit worn and battered now, what pads do people recommend? I don't want to spend ridiculous amounts of cash, and the bike is only used on the road.

[Good Evening!]

That's similar to what the guy said when he collected the CBR.

The CBR600 was a 1991 model though, and the R6 is 2002

[Good Evening!]

Getting excited, collect the bike on Friday

Are the flighty front wheel handling rumours of the R6 true? Or just applicable to the later models? Thinking I should order a steering damper for when I get the bike?

[Why do people buy new 125's]

I have a friend who bought a new RS125, he was quite upset when he came out with me to look at some bikes when he could have done his DAS and bought a mid 90s 600 sports for the same cost as his 125.

[Good Evening!]

Thought I'd give you all a shout and say Hi.

I'm from the Cheshire in England, and have recently bought a 2002 R6 after selling my CBR600.

I'm looking forward to chatting to you guys and finding my way around the forum.