LCGB Forums

Hi all,

Anyone know whether there is a free-flowing air filter available for the Spanish toolbox type airbox? I note that there is a airhose available to upgrade to a 22mm carb but the standard Serveta filter is fairly small and restrictive. I'm considering an upgrade to a reamed 22-24mm carb but have my doubts that the standard filter will pass a suitable volume of air, even with a modified airbox.

Anyone know of an uprated filter.

Adam

I seem to remember that Scooter Loopy John did an interesting airbox conversion Adam. I don't suppose that particular thread is still around, but it would be worth tracking him down. Basically he blanked off the existing breather, did away with the partition and made a new aperture for a foam filter to sit inside the toolbox itself. Quite an interesting idea I thought.

Yes, I remember SLJ carrying out that conversion. I may have to search it out.

Ta

I'm running an Avanti with a TMX 35. I was using a Breathsweet filter but found it was crushing slightly under the panels. It still worked but wasn't happy with it.

I've now fitted a Spanish toolbox and made my own filter. The inlet and outlet holes on the toolbox are very small and I have enlarged them, fitting a wider pipe to the outlet so my Breathsweet bellows will fit over it and cutting a large section out of the front, above the existing inlet pipe. I had to use a standard lid and drilled numerous holes to allow air in. For my initial run I had some wire mesh and foam over the toolbox inlet. My first run was not successful and the scooter would only run with the door removed. My second attempt required the foam to be removed. This ran fairly well but was still boggy at mid-range. I have now cut a hole in the carb' side of the tool box and fitted an additional filter. This is looking more promising, although I may fit a second hole or enlarge the first.

Obviously with a 22mm carb' you should have more success but I assume the original spec' was probably boarder line or slightly under performed with the restrictive inlet and outlet....both should have been bigger..........IMO

MickYork wrote:I'm running an Avanti with a TMX 35. I was using a Breathsweet filter but found it was crushing slightly under the panels. It still worked but wasn't happy with it.

I've now fitted a Spanish toolbox and made my own filter. The inlet and outlet holes on the toolbox are very small and I have enlarged them, fitting a wider pipe to the outlet so my Breathsweet bellows will fit over it and cutting a large section out of the front, above the existing inlet pipe. I had to use a standard lid and drilled numerous holes to allow air in. For my initial run I had some wire mesh and foam over the toolbox inlet. My first run was not successful and the scooter would only run with the door removed. My second attempt required the foam to be removed. This ran fairly well but was still boggy at mid-range. I have now cut a hole in the carb' side of the tool box and fitted an additional filter. This is looking more promising, although I may fit a second hole or enlarge the first.

Obviously with a 22mm carb' you should have more success but I assume the original spec' was probably boarder line or slightly under performed with the restrictive inlet and outlet....both should have been bigger..........IMO

Very interesting reading as I am of the opinion that there must be many of 'us' that have adopted a more civilised(?) approach with filtering the inlet yet many must be strangling/restricting the full potential of the engine. Not only that, but there is the real danger of overheating as a consequence IMHO.

You are on the best course, by the sound of it, as you are drawing in cold air.

Perhaps Serveta were right in the way they went with moving the air filter to the toolbox as its not too difficult to imagine that location as more of a baffled 'plenum chamber' with cold air drawn/forced in from the stand plate area to then be filtered as a fresh, cold air feed to the inlet.

Thanks for the responses guys. I'm a long way from coming back to you with any feedback as I still have the motor to strip and rebuild before it sees the road, however, this is all very useful food for thought.

I'm not surprised by Mick finding that he's ended up stripping the filter mesh/foam out of the box and having to drill a number of holes in the box to increase flow to it as I recently went through the same when trying to supply enough air to a 30mm PHBH. I too found that the standard SIII airbox needed drilling, even once the kidney was out and the neck increased in size. As such, I'd already started to think down the lines of drilling the Spanish airbox side to further increase flow, even if only using a 22 or 24mm carb. I really don't like the idea of running an air cleaner system that doesn't supply sufficient volume to satisfy the motor.

Thanks again... interesting reading (for me at least).

Adam