Back of the garage


Staff member
A while ago, because of the SU conversion, I did a mod to the air filter set up on Bonnie

It worked pretty well but was always a little bit noisy and when I replaced the filter last year with a bigger one it was very noisy. So I had a bit of a fiddle with some bits and pieces I had laying around.

I had an old K&N cone filter and offered it up to the original air box

A little bit shallow but the rest fitted nicely so a little bit of packing required

The inlet tract is a bit small so I welded on a length of 1 3/4" tube instead

Nice fit

A 3" domestic gutter downpipe elbow was a good fit on the carb side, just needed a little heat to push it on

The other end was secured by extending the original wing bolt to the carb elbow

It fits in it's new position - just

I did all this months ago and finally got a chance to try it out and it's so much quieter. Before, if you put your foot down, the induction roar was just too much for such an elegant lady but now, along with all my other sound deadening additions, the cab is a far more pleasant place to be and as a bonus she seems to be a bit more sprightly:).
This was a bit of an experiment so some tidying up to do and a cleaning kit for the K&N to order.


Staff member
You can see from Bonnies engine bay pic that, with the SU carb, the original accelerator cable sits at an awkward angle and makes it a little stiff. Harvey was the same and eventually the cable frayed up and jammed :confused:
So I fixed it with a noodle:)

and a universal push bike cable cut down to size

The run is now nice and smooth with no kinks

Got plenty to sort Bonnie out as well, all sorted for about a tenner:)


Staff member
Now Bonnie's new air filter set up has proved itself I decided to make the installation a bit more permanent

First job was to recondition the very dirty and tired K&N with this £15 ebay purchase. Pic show it after treatment with the cleaner supplied, it works very well

I cut down a rubber ring that came with the filter I previously removed and fixed it to the air box to replace the foam.

Sits just right

Filter all oiled up

While the air box was out I fitted a noodle to Bonnie's accelerator cable

Jack nuts fitted to secure the air box bracket, note the several attempts to get the right position :rolleyes:

Secured with a couple of stainless button head screws

Just need to use her now:)