Airbox Modification Guide for a YZF1000R.
By Nihat HasbekImportant !!
Do not operate the motorcycle after applying this modification, without also rejetting the mainjets. The increase in air will cause the engine to run VERY lean!!Most YZF1000R’s need main jet sizes of about #160 after this modification. The only way to find out the exact size of main jet needed is to do a dyno run and depending on the results, installing the right size main jet. Also finetune the needle position while doing a dynorun.
Use of this modification in conjuntion with a Jet-kit (Dynojet/Factory) will have the best results.
As stated above, the main jets of the jet-kit can not be used. This modification needs much larger size main jets.
To be able to fully take advantage of this Airbox Modification, which is based on feeding as much air as possible to the engine, the "Air-scoop" at the front of the bike needs to be open.
In picture 1 , the "Air-scoop" is located just above the radiator. On ’96 models YZF1000R’s this scoop is already open. On ’97 (and up) models there is a vertical edge in front of it about 3cm high as seen on picture 1. This vertical edge needs to be cut away, so the front of the scoop is
opened up.
Cut this edge out of the "Air-scoop"
Picture 1
The next step is to open the normal Air-intake on the top-side of the Airbox.
Take of the flat Air-intake tube/cap. Also take out the long metal tube which sticks in the middle of the Air-filter in the bottom of the airbox in a reinforced cross. Also take off the rubber airfilter inlet ring as seen on picture 2. To make sure that the airfilter won’t bounce up and down during riding, the filter must be taped only around the edges to the airbox.
Picture 2
Take out the long metal tube where the screw
of the air-intake cap normally sits in.
On the bottom of the airbox, the reinforced plastic cross is visible in this picture.
NOTE: it is advisable to also make a dynorun with the rubber ring on top of the airfilter to see if there is a difference, and after that make a final choice.
In picture 3 , the reinforced cross on the bottom of the airbox is also visible from the outside of the airbox. The next step is to cut out an oval shape, exactly the same shape, but in a smaller size as the airfilte opening in the top-side of the airbox (size should be about the inner diameter of the airfilter) The airfilter can be used to draw out this oval shape on the bottom outside of the airbox. The shape can be slightly bigger than the inner diameter of the airfilter, but leave enough of an edge for the foam of the airfilter to rest on, so as not to cause an air-leak.
The oval shape must be cut out of the bottom in 4 quarters! This leaves the reinforced cross intact and also prevents the airfilter from falling trough the bottom of the air-box.
Picture 3
Cut out the oval hole in 4 quarters, while
leaving the reinforced cross in the middle intact.
For this step the 2 halves of the airbox need to be taken apart, by taking out the screws around the airbox. In the bottom of the airbox are 4 tubes located of which the bottom sides slide over the carburetors when installing the airbox. After opening the airbox, these tubes can be taken out and made shorter. The tubes should be made 2cm shorter on the sides that stick inside the airbox.
When closing the airbox, silicone paste (the stuff they use to make watertight sealing in bathrooms) can be used to seal the airbox up again (also around the 4 tubes).
Picture 4
the airbox.
Disclosure: Writer of this document is/will not be responsible for any damage to any part of a motorcycle even remotely related because of using this modification.