Avanti TT3

Avanti TT3

Regular price £599.00

And Now For Something Completely Different

The New Super Cool

Avanti TT3

It Runs At 30% Cooler than any other air cooled Lambretta Kit

(Test carried out at JB Tuning on 13th May 2011)

Finally after 18 months of design and development we can now release the details of the all new Avanti 225 TT3, not since the TS1 has there been such a radical design change, not one but THREE.

1. The first Lambretta cylinder to give over 30% more radial fin cooling area than an Innocenti
      External cylinder temperature on the Dynamometer at JB tuning 90 degrees C
      Other well known kits run at 140 degrees C+(source: JB Tuning)  

2. The first Lambretta production produced centrally bridged exhaust port

3. The Unique MWO transfer port, conventional transfer fed 3rd port opposite the exhaust port

100% designed and manufactured in England apart from the Mitaka piston which has a standard compression height, designed by us and specially manufactured for the Avanti kit so as to fit any standard 107mm conrod crankshaft.

As with all 2stroke engines heat is the number one enemy and has been even more exasperated by the legislation of compulsory usage of unleaded fuel which in itself burns hotter than leaded fuel,

Not only do we have to put up with unleaded fuel but also the ever increasing amount of additives being covertly added which include oil dispersants of different types. If you have found that your cylinder is relatively dry but your crankcase has excessive oil then this is in part the reason why.    

Because of the above it has influenced our most recent design for a touring type kit.

The Head

A standard head is approximately 140mm in diameter, the Avanti being 180mm in diameter has a far greater cooling efficiency; the design has also taken into account the need to be anti warp.     

The head has a central combustion chamber, being recessed it excludes the need for a head gasket and has a set squish clearance of 1.5mm which can be adjusted by the use of base gaskets, the compression ratio is 10:1

The Cylinder

MWO Transfer Port

Central Bridged Exhaust Port


Following the same theme the cylinder has at least 30% more cooling fin area than a standard Innocenti Cylinder and in some cases over 50% more than some other alloy kits that are on the market. Put it another way look at your own Lambretta cylinder (any) now add on 20mm to any fin you are looking at, on each side of the diameter! You will see not all the fins are uniform, the reasons why will become obvious when the cylinder is fitted. 

The cylinder also incorporates a central bridged exhaust port; the piston has 2 small oil holes to help lubricate the bridge. The bore utilises the now common Nickel Silicone Carbide platting and last but by no means least, our unique MWO transfer ports, located opposite the exhaust port, are feed from both standard transfer ports by looping over the cylinder studs; this is not a boost port. We believe this is another first on a piston ported Lambretta cylinder.

The Piston

Manufactured by Mitaka to our design, 2 x 1mm rings, full length skirt & standard 16mm gudgeon pin. 

(Note: the piston pictured is not the one being supplied)

The Head Cowl

Our own head cowl designed to fit our kit.

(Note: cowls will be supplied in white only)

Included: inlet, exhaust & base gaskets, studs and nuts.
Fitting instructions.

Technical Specification


Demonstrator Set Up

Avanti TT3 kit with 10:1 compression Ratio

Gear Box:     LI150 with 47 / 18 sprockets = 4.4:1

Carburetor:   Dellorto 30mm VHSH 125 main 55 pilot

Exhaust:        Franspeed Race / Avanti Clubman

Ignition:         17 degrees BTC Sil Lightened Flywheel

Crankshaft:    MEC 58mm Full Circle

Clutch:           Standard 5 plate / strong springs

Exhaust test


Compression Ratio's

The Avanti TT3 is a versatile sports tourer developing around 24bhp and being able to pull up to 4.44:1 gearing depending on what exhaust is used. Please advise us on what your ideal road requirements are and we will be please to advise you on the set up that would suit you best.

Avanti TT3 Fitting Instructions & Kit Content: Download


Copyright: Please note the design of this kit has been carried out solely by Ron Moss who owns the Intellectual Property Rights of the Avanti TT and the Avanti TT3 cylinder kits.

Adam Winstone – Cad work
Peter Brunskil – Head Cowl Pattern
Ben Moss – Animation
Jack Moss – Website Design

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