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I don't like running open mouthed carbs, although I'm not totally averse to the idea.

I rode to Davos with this same engine (in a different Lambretta, mind) with an MB panel filter. Despite the GT being a reed valve, every day mid afternoon, I'd have to stop and clean the filter as it was clogged up and really strangling the engine.

When I came back, I ditched the panel filter and replaced it with a Breathe Sweet. However, it was a Series 2 and I could do that. With a PHBH 30 and the GT manifold I have, the Breathe Sweet won't fit inside my Series 3 panels.

Anyway, that's the history of why I have arrived at this:

Don't look that there's much chance of that fitting inside the panel

It's foam, it's designed to press against the panel but to leave a pocket of air around the bellmouth (a small one by the time it is compressed though)which the MB panel filter doesn't.

I know I need to test it myself but I need the DVLA to sort a registration number for me first.

Just thought I'd post it up in case anyone had any thoughts or experiences

That looks interesting, I have just bought a shallow Marchauld filter from MB but not sure of panel clearance yet.

It'll have to compress quite a lot,the panel fits to the inside of the inside plastic runner strip.

coaster wrote:That looks interesting, I have just bought a shallow Marchauld filter from MB but not sure of panel clearance yet.

I'm running one on my left hand side gt186 manifold in a series 3. Just touches the panel and clips around 1bhp off the peak power.

dickie wrote:

coaster wrote:That looks interesting, I have just bought a shallow Marchauld filter from MB but not sure of panel clearance yet.

I'm running one on my left hand side gt186 manifold in a series 3. Just touches the panel and clips around 1bhp off the peak power.

Do you mean compared to without a filter or because it is pushed up against the panel?

Cheers

Same bike, same dyno. Runs 10 minutes apart. One with side panel fitted but no filter, the other with side panel and filter fitted.

This engine peaks around 7000rpm and makes 14bhp without the filter

I opted to lose one bhp in order to gain the protection of a filter.

dickie wrote:

coaster wrote:That looks interesting, I have just bought a shallow Marchauld filter from MB but not sure of panel clearance yet.

I'm running one on my left hand side gt186 manifold in a series 3. Just touches the panel and clips around 1bhp off the peak power.

Mine is on a GT240 kit with the manifold on the off side and the panel goes on ok but does partially touch. Not able to road test just yet

That's interesting Dickie, a loss of only 1bhp for extra life on the barrel and piston is well worth it.

I've got a Marchald too, straight onto a 26mm PHBH and GT186. Mate fabricated a vent/scoop into the side panel as it was right up against the panel and wanted a good airflow into the filter. Going onto the dyno tomorrow so will be able to see how it breathes but can't compare too old elbow and RamAir filter as the GT is replacing my old Suzuki conversion.

Apologies to OP if gone a bit off topic.

Mark

I had to modify my panel and cut down toolbox to get my sweetbreather to fit upright. Ive seen a pic of one of the CamLam guys scooter with the sweetbreather fitted horizontally pointing backwards.have you tried that? I think whatever way it goes the foam will never be free on compression.

jonno wrote:I had to modify my panel and cut down toolbox to get my sweetbreather to fit upright. Ive seen a pic of one of the CamLam guys scooter with the sweetbreather fitted horizontally pointing backwards.have you tried that? I think whatever way it goes the foam will never be free on compression.

Jonno, I have used an elbow/RamAir in the horizontal position and it worked well. However I changed the engine's set up and then found that it held back in the higher rev range, the flywheel's air flow seemed to affect the carb's ability to draw air in through the filter. Put it in the vertical position and all was well.

What is the orange filter off? Couldn't it be trimmed, so it doesn't compress as much?

The Breathe Sweet is not an option whichever way you fit it as the rubber elbow is compressed too much. I could take the manifold off and get it machined down to shorten the inlet tract but I'd probably just run it open rather than go to that trouble.

I'll give the filter a go and take it from there. I'll report back.

+ 1 on Fred's questions... 1. what is the filter off/what is it supposed to filter? Without seeing it in the flesh (tone, groan...) I imagine if the the inside edges are chamfered with a pair of scissors, angled to be as close to 90 degrees to the sidepanel as possible, with careful fitting of panel, so as not to double up the foam in the carb mouth this could be an interesting option (dyno 1st eh!)... Ugly as sin & somewhat hospital stylee, but if it works...

SORRY! Correction... Not flesh tone, I meant trump tone

I bought it from Darrell Taylor. It's a Twin Air but what it is from, I don't know.

Cheerz chap, will be interested in your updates...

Looks interesting Paul - If you can get it to fit then it looks like the best of that type of filter I've seen

Scoot's looking great by the way

There was a thread about these filters on here or scooterotica a couple of years ago (ish) ....the filter's off a KTM