As per title really. I fancy a couple of K&N filters for the twin Dellortos. They currently have trumpets fitted and I wondered if anyone knows what to do about trumpets - do I even need them? If so the clearance between end of trumpet and the steel plate of the K&N.

Also, got the throttle cable sorted today - so I now have full travel, cant wait to go out and give it a go. Tried it last weekend, but didnt have the last 1/4 to 1/3 of throttle travel. I guess that last third will make a big difference....

The trumpets smooth of the airflow and give more torque. Ideally you need the longest trumpets you can fit inside the filter whilst leaving a minimum of 19mm between the inside of the filter and the mouth of the trumpet. It is preferable to have around 32mm clearance if you can get it though

Yep - as above you do need the trumpets to get the airflow smoothed. Different length trumpets will effect the power and torque characteristics too. Give at least an inch of clearance to the filters.