(T) air box

i have a 899 sx with the infamous flat spot. ive read that you need to upgrade the induction system either by fitting a high flow filter element and drilling holes in the bottom of the airbox to allow more air in or just fitting a custom air induction kit. these can be quite expensive by the looks of things so my question is can i replace mine with a sporting air box? do the sportings suffer from this flat spot aswell? or should i just stump up for a new filter? money is an issue at the mo as ive spent a LOT getting it through the mot.

cheers for any advice

Its the 1108 that has the imfamous flat spot, not the 899, however the 899's inlet manifold is higher than the 1108 so you can't put a sporting filter on. That leaves putting something else on the end of the 'bob', or throttle body cap.

Do a search on here and you'll find plenty of suggestions along the lines of the GSR one.

Could be worth a try.

Cheers

D

ah. maybe mine wants to be a grown up 1108? hehe. might go for the k&n replacement filter when i do the head gasket etc. how often do you have to clean these?

cheers for the info btw

If you are doing a head gasket on an 899 cos its overheated, lap the valves in. Reduces the chance of a high spot on a valve or seat causing problems later.

Been there, done that.

Cheers

D

If you have a spare 90 notes (IIRC), get in touch with GSR. The BMC induction kit they offer (F2i, I believe) is really impressive. I fitted one to a Cinq SX last weekend and it revs so much easier and is much more throttle resposive. Not to mention the huge roar it makes in 2nd and 3rd

Just to add:

With the kit I've spoken about, you will need to get hold of a seperate oil breather filter though. K&N do one for about £15 but why pay that when halfords sell a Ripspeed one for £8.99?!

Just wish I'd taken a few pics to show you how it's done now

If you reroute the breather hose you can connect it to an threaded airline fitting, which you screw into the plastic cap