Scooterotica

Hi all.

I will spare you the complete background, beyond to say that I'm a long-time motorbike dork who's just dipped his feet into the world of Lambrettas. Just got a derelict LI 150 back on the road after a near-complete (and entirely not-intentional or desired) rebuild, thanks to a lot of help from Sticky's book and a lot of lurking on here. The plan was to turn it into something, I dunno... more-casual than my motorbikes that could get me and a girl and a case of beer to wherever I decide to park it with a minimum of fuss and drama, and I almost got that. The only problem now is that the LI is loud. Really, really loud. Louder at idle than my Triumph with straight, unbaffled TT pipes. And that really cuts into the "minimum of... drama" bit when I ride it.

So here's what I've got: Muggy 186 v.4 kit with matched block and manifolds. PHBH 26. Ancillotti clubman. (All of the prior sourced from Cam Lam.) Standard gear and drive ratios (willing to change if necessary). Standard wheel and tire size.

Here's what I plan to do with it: Low-key blasting around town with occasional longer-distance runs at a comfortable 55, and nothing more than a couple or three hundred miles in a day. Riding two-up with said girl (I'm 190 lbs, she's much, much less) and case of beer, and I'd like to be able to go up hills at a not-pitiful speed. Winding it out on occasion is fun, but I don't want to have to rev the nuts off of it in daily riding. I have motorbikes to go far and fast, but I would like to keep up with traffic in town.

And really, as it sits right now, it's pretty much good as-is. Still has drums both ends, and still no dampers up front, so top speed is (definitely) not a goal, but it has enough go to tear away from a stop light and seems like it'll haul enough weight (haven't tried, since it went back on the road three days ago). It's just too damn loud.

So now to my questions: Is there another pipe (clubman or expansion) that will give me similar performance with less noise? Alternatively, is there another pipe that will give me a little more performance down low (keeping in mind my intended use for the bike) with similar noise. My understanding is that the JL3 road is still going to be more peaky, the JL3 snail just sucks, and most other expansion chambers are going to be even more top-end oriented. Then there are the other clubmans, all of which will cut into performance, save maybe the Gori, which looks great, but is probably even louder and too big anyway.

... or at least that's what all I've taken away from the research I've done on this forum. Most of what I see is (understandably) more biased toward higher-revving engines or old-school tuning on iron barrels, and is thus maybe not applicable here. It wouldn't surprise me if there's a niche-market pipe that's exactly what I'm looking for, but I just don't know about it and haven't found it in my search, which is why I'm asking.

The obvious option is probably to fit the Ancillotti "retrobooster", which I assume muffles the sound of the Ancillotti somewhat, but there's one final complicating factor: I'm in the U.S., and ordering from the U.K. (or anywhere in the E.U. for that matter) costs a lot. That also means it's extremely unlikely I can find someone even relatively local who has a given pipe to listen to it. I'd really like to not order something, fit it, and then find out it's still far louder than what I'm looking for. I don't mind spending the money to get what I want out of this thing, but I'd rather not sink huge piles of dollars into shipping hollow metal across the ocean more than once.

Thanks for any advice you can give, and apologies for the length of this, but I wanted to hit all of the pertinent details in a single go.

Hello Ghost,

Yes, quite an essay. If I might summarize.

You have an Li150 but you have now bought a V4 Mugello 186 for it (good choice - a quality kit). However, the exhaust pipe is louder than your motorcycle, and you see this as a problem.

I don't, and you might be hard pressed to find other on here that disagree with my opinion. If I might para-phrase Gordon Geko, "Loud is good" (especially if it is louder than a m/c).

But seriously, it would appear from your description that the pipe is exceptionally loud but I can't decide from your description whether the Mugello, carb and pipe supplied by CamLam have been fitted to the re-built engine, or whether you have rebuilt the engine as an Li150 (with original exhaust which is noisy) and the new parts are now sitting in a box awaiting installation.

What I am trying to get at is; is the Ancilotti clubman supplied by CamLam the noisy pipe?

Is the exhaust you have fitted blowing anywhere, either u-pipe or flange, if you cover the end of the tailpipe does the engine go quiet then stall at tick over, or does it carry on running blowing smoke from elsewhere?

Knowledge wrote: I don't, and you might be hard pressed to find other on here that disagree with my opinion. If I might para-phrase Gordon Geko, "Loud is good" (especially if it is louder than a m/c).

Nonsense. Too loud and you sound like a bike stuck in second gear.

And you end up joining the Harley types that everyone laughs, points at and shouts COCK when they ride by making a f@@king racket.

Well, I didn't have to press very hard to find someone to disagree with me. I stand corrected, though my scooter will never sound like a Harley, as it does more than 4rpm (just)

Anyway, back to Ghost's enquiry ...................... Good point J1ms.^

or is it that previously having bikes hes just not used to the racket a lammy makes ????

I built an engine with exactly that setup recently, goes very nicely, ideal for the OP's intended use I'd say and doesn't seem offensively loud... but I'm perhaps more used to hearing scooters making more noise...?
didn't someone post a video up of a retrobooster fitted ? red ghost maybe ?

Good questions and points, all.

The Triumph makes plenty of racket. I was just hoping the Lambretta would be a little lower-key, and was kind of surprised when what I thought was supposed to be a relatively quiet pipe ended up being as loud as it is.

The engine is built as described, with the Muggy, the PHBH, the Ancillotti, etc. Stock, it was quiet, and I didn't want or expect anything like that. There's no obvious leak in the pipe, and when I cover the end of the pipe, the engine dies quickly (within five revolutions or so) without blowing smoke from the joints.

It seems going quieter probably isn't an option (aside from maybe the retrobooster, and if anyone can find a clip of one, I'd be really appreciative), so I guess the real question becomes: Is an Ancillotti really that much quieter than an expansion chamber on a Lambretta, and if not, is there a better pipe out there for midrange power with that setup?

(Re-reading this, I realize how stupid this question has become at this point. "I'm really happy with everything but the noise, which I can't really change, so what can I change instead?" I still feel compelled to ask anyway.)

My ears were burning...

I made this little end-can myself, it does cut the db's a bit..

This is with a std 150 iron barrel.. I have now updated to the same mugello kit but with a 60/110 crank. To me now, my scoot seems to pretty much the same volume wise...

Any questions just ask..

and I know what question is comming....

Nice can, RG.

I do have a question or few, though maybe not the one you're expecting. Is that a perf-core glasspack, or is there something else going on there, and if so, what? Also, what's the I.D. of the core, and what'd you pack the baffle with (and how's it holding up)? Finally, assuming it is a glasspack, is the core straight or flared?

Again, I'm new to Lambrettas, and I'm pretty new to two-strokes in general. I know the general principles by which an expansion chamber works, but box exhausts are a complete mystery to me. I know that stinger length is a major tuning consideration on expansions, so I figure boxes are probably the same, and wasn't sure exactly how to build a silencer that wouldn't upset that.

Also, just practically, I've never built a can or a baffle for a pipe that small and have no idea whether any of the perf sheet I have is even appropriate, or whether any of the packing is going to survive two-stroke exhaust.

Dammit. Kind of thought I was close to done with this one.