KevShek

The bike seems fine, its my daily ride and ive noticed no adverse effects. On the back of that, i emailed dyno jet regarding a map for fitting the filter, and they said it didnt need one, as it doesnt have enough of an effect fueling wise that compensation is needed. This is also mentioned on their site, where they have tested bikes with k&n filter.

And heres some info on the exhaust http://www.yamahaclub.com/forums/index.php?showtopic=17219

I managed to get hold of an 08 exhaust from ebay for £40 so i thought id mess about with that and keep mine stock if i need to swap it back. Performance system range from about £300 upwards so for 40 quid, it was worth a shot. I had a friend cut and reweld the stock exhaust to see what he could do with it. Heres some pictures of the standard system. Above is a picture of what looks like a restrictor, this bulged section contained a honeycomb like cross section. To the right, you can just see the small tube coming off the exhaust, this is the fresh air bypass tube which comes from the valve on the bike. Aftermarket exhaust wont have this tube on it. Heres the exhaust back from my mate. The first thing my mate done was to chop out the restrictor section and reweld and new section of pipe. Next he removed the small tube and welded it closed. Finally, he cut out the cat section and drilled out the centre so it was hollow. He then rewelded that back on. There was little we could do with the rear can, as it would be baffled and the engine would need some form of back pressure. Results wise, it seems to ride just as good, however i have noticed that the top end is better, i can maintain motorway speed easier, and the bike pulls better up high rpm. I have however fitted both my air filter mod and now the exhaust in conjuction with a power commander 3 and its now running a more aggressive fuel map.

It seems perfectly fine, but I haven't had a proper ride of it yet. I won't get a chance till tomorow when I goto work. Ill keep updating the thread.

Here you go peeps, so more info. http://www.yamahaclub.com/forums/index.php?showtopic=17033 Next mod will be the exhaust, another cheap mod when that happens hopefully.

I had a bit of spare time, and a few bits lying around so i thought id make my own performance air filter. I simply begrudge spending £90-100+ for a JR, K&N or BMC one, beside, i dont have that amount of money! So with a few bits i had lying around, i decided to make my own. Even if i made a hash of it, all id do is buy a new air filter from yamaha. and heres how i did it. First thing first, i had no idea what the standard air filter looked like so i remove the tank cover, and the tank, and unscrewed the air box to find this. Above if the filter. This is how its positioned looking down onto the bike. It paper pleats on this side. Its around 1 inch thick. The plastic surrounds the the filter and is about mid way all the way round. This edge is how it sits into the airbox, what youre left with is a rectangular filter in the middle. On the underside, there is a metal gauze, which if you look carefully, you will see, it plastic welded on the 4 corners. Next i dug about and found an old HKS air filter i had lying about from one of my old jap cars. This is a 3 stage foam filter (the one on the right) Luckily, the casing just seperates and i could take out the foam, which is about 3/4 inch thick. The first thing i did was to tear out all of the paper element. This is messy and tedious. Using a combination of hot soapy water, and scraper, and flat screw driver, i cleaned it up as best i could. I was careful not to damage or disturb the metal gauze. On each of the 4 corners, there was a piece of plastic which comes all the way up flush to the top. I simple snaped them off, NOT TOO FAR THOUGH, cos the bottom of them is what holds the gauze on. I used a stanley knife and carefully trimmed it flush to the sides and left about 1/4 inch. After looking at the filter a bit, i decided that the original gauze may not be sufficiently strong enough to support the pressure of the filter pushing down on it when the engine is reviing, so i dug out some diamond aluminum gauze i had lying about. You can buy this stuff from B&Q in a large sheet (like i did a while back) Using a pair of heavy duty scissors, i placed the gauze on top of the filter area and carefully cut out the net shape to allow me to fit it into the filter housing. I then bent up the sides like so and pushed it into the housing as far as it would go (which is about 3/4 inch into it) I then cut off the excess leaving approx 10-12mm so i could then fold over the lip. This would also help support the force on the filter. Next step, i cut the foam filter to size, and pushed it into the housing like so. Voila! and there you have it. One performance air filter for no bucks! Final step, is simply refitting it all up. FIRST IMPRESSIONS I managed to take the bike for a quick spin (literally) round the block, but the initial report is that the bike seems to pull much better through the revs. Basically it revs more freely. So for no money, its gotta be worth it! Enjoy!

Ok, ive taken the plunge and have blocked off the pipe. After tracking back the tube toward the airbox, ive notice it fits into the side of the throttle body. From what i can see, it just bleeds off some of the air coming in so the engine isnt get the full amount. For those who dont know what weve been talking about, i took the liberty of taking a few pics for you to explain. After removing the right hand side panel, youll see the side of the engine. Up on the top half youll see this black box mounted on a bracket. This is the "air valve" (second pic down). If you still unsure, look down at the exhaust from the front and youll find this black rubber pipe (which im holding) Follow that back and youll hit the air valve. All i did was chop out the middle section of the rubber pipe, and left enough tube at each end to plug it up with. On the valve side, i simply use a plastic bung i had lying around. This was a perfect fit. I re-fitted a clamp around it just to make double sure. Down at the exhaust end, i simply used a short bolt with the correct diameter to match the tubing, and also clamped that too. Hopefully, it might feel a tad better, especially with a headwind....... uphill!

Thanks for that infomate, so from what it would seem, simply cutting that tube to the exhaust and blanking it off both side could be benificial. The only reason I can think of is it would only allow the air into the engine, and more air would certainly give better performance albeit just a slight improvement. Not bad I suppose for a free mod. I'm. Personally won't be chabging bikes for a long while so would like to tune up this one.

oh, another thing, has anyone noticed this?? http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...em=320332783423

ive been hunting around for this thread and was helpfully pointed to it again. im not 100% sure how the air box mod benifits the engine. From what i can tell, its talking about the valve system which connects to the exhaust. Ive just had my bike back from 1st service and i asked about that box. I was told its an air circulation system, where air is taken from the airbox and piped out directly into the exhaust. When asked what the purpose was for, its so fresh air can bypass the engine, out into the exhaust, for a cleaner emission result. But i have been told "Getting rid of it can help slightly (and make it rather easier to get the fueling right), just don't expect large increases. There are 2 reasons for similar systems. Either to feed fresh air into the exhaust and complete combustion, or to feed exhaust gases back into the engine to reduce combustion temperatures (reduces the emissions of oxides of nitrogen). " Im considering getting a LeoVince exhaust sometime soon, so will know then if this system has the same return pipe on the exhaust.

I too am interested in hearing more about this CDI unit? any further ifno? part number maybe?