Blinding

Get your self over to the R125 forum. The people there have a vested interest in you, your question and finding you an answer we all have an R125 . http://www.yamahar125.com/forum/index.php Also, becuase the R125 is a 4 stroker, it has been designed to produce the 15hp at the flywheel, to get more out of this engine requires tuning and stressing the standard components. There is no washer to remove from the exhaust or YPVS valve in the exhaust port to turn etc etc. There is a 150CC cylinder available from Yamaha and a 180CC cylinder from malossi which may be a good next step for your bike, but like I said get over to the 125 forum and youll get lots more answers to your questions. Blinding

Phew busy night.. Anyone seen this? My link I would buy one of them bore kits.

Ive just hit 1000 miles in mine, I get 84mph on the limiter, not a regular occurance but it does happen. All I will say is I have been suprised that when I got to 600 miles i thought "thats it, all run in" but its not. The engine is getting looser all the time. It spins up so much quicker than it did. I also find winding it up to 9k and keeping the revs between 7500 and 9000 is the most fun. It is a 125 and unless you wanna spend a fortune on squeezing every last hp out of it you should like me, accept it is a 4stroke 125. Here is something that everyone that owns a R125 should know... 13.8L Tank Capacity = 3.04 Gallons 12.2L / 4.539 = 2.69 Gallons 1.6L Reserve / 4.539 = 0.35 Gallons 275.9 miles on a tank 275.9 / 2.69 = 102.5MPG 0.35 * 102.5 = 35.87 miles 112p/Litre 13.8 * 112 = £15.45 12.2 * 112 = £13.66 3.04 * 102.5 = 311.6 miles Im running mine on Shell Super Unleaded, every octane helps Blinding

Fatboy, You said "iv had 84 off the limiter", as have I, without changing the gear ratio you will still only reach that limiter and the 84mph. To add 13 mph you would need to change sprockets. Blinding.

My dealer tried to sell me an exhaust for it, removing the cats. At £400 im not interested, its only a 125 and for £400 I could pass my test and trade it in on an R6.. Blinding

Mania, I had to post a reply as I have seen two TZR 125's do over 100 mph. One had a smaller rear sprock and the other, mine, was completely standard except for the valve being turned. Totally agree with everything else you said tho. I had my R125 bouncing of the limiter earlier, a sad moment. Blinding.

Does anyone know if the top of the airbox on the R125 will fit the oposite way around to that shown? I am thinking that an easy HP gain could be to ram air into the box inlets!

The compresion build up can spin the engine back if the crank doesnt pass top dead center. It is common.

Glad it wasnt serious, but I know what a let down feeling it is when all you want to do is ride it and it just wont let ya.

Yamaha man, I just ran in my YZF-R125 as per the owners book. Check out this thread http://www.yamahaclub.com/forums/index.php?showtopic=18525 Vince

Guys dont forget that assuming you weigh 60 Kg, approx 10.5 st, on the YZF-R125, a total of some 200Kg an increase of 1-2 hp is a gain of 5-10 bhp per ton an increase from 75BHP per ton to 85... The standard exhaust weighs something like 4 kilos and a leovince, scorpion weighs a quarter of that which again increases the bhp/ton This bike may be restricted electronicaly but as with a car engine the increase in power comes from tuning.. I have noticed on mine the top of the air filter box has the inlets on the back of it. I've not had the tank off so cannot see the shape of the filter box but it looks like it may be possible to rotate the top through 180 degrees and feed cool air into the box. This could achieve a ram effect! Can anyone confirm if the top of the box can be rotated?

Alex, Did you follow these run in recomendations....? I thought it sounded suspect and then when I got to the bottom of the page I saw "Smaller ports = 7% more power" LOL Whilst this may be true of an engine with a head on it that contains too large ports and valves, eg. the ford two litre engine as fitted to the MkII RS2000, where it has been proven that fuel drop out occurs when the intake speed falls too low due to the large port and low air pressure, this is not true of most engines. I personally will disregard mototuneusa's comments. Vince

Ian, Owners book say first service is at 600 miles and that includes an oil and filter change. Mine went in at the weekend just turned 660 miles. Parts were £14 ish labour was 80 ish £100 all in. This bike is so nimble very chuckable im using mine to commute every day what ever the weather. Saving a fortune over the car, in fact the car is up for sale now. Im planning on doing my test just to lose the L plates. Will upgrade next year some time. Have fun. Vince

<300 miles < 6000rpm <600 miles < 8000rpm 601> any.... I bought mine 1 august couldnt wait for the 59 plate, i just had to get one. under 6000 rpm is a lonely 50mph, expect cars to pass. I did not enjoy those first miles. under 8000 rpm is 65mph you can keep up with them but I whooped when I passed the 600 oh and after the first oil/filter change, very important. Now i reach the speed limit . Need a new exhaust though the stock one is suprisingly heavy. I bought the black one, I like the blue but seen loads of blue r1's, seems a common color choice. Have fun. Just visited that url above. I am just wondering why do the caparison pictures of pistons show the crown on the piston is completly clean. I dont care how the engine was run in, if you run an engine the crown of the piston will always have carbon deposits on it! Looks like a load of nonsence to me but I have run mine in as per manufacturers instructions and it runs fine. Good luck. I would be interested in the experience you have with that run in method and speed to gear mappings!

I got a white Tiger. Well comfy + 5 stars