How does the new BGM 177 aluminum barrel for the 125/150 cc largeframe Vespas compare to the most powerful contender in its class, the Quattrini M1X?
Since the 1960s millions of 125/150 Vespas and their derivatives have been built which is why the market for tuning barrel kits for these models is highly competitive and currently undergoing a revival. Several brands now offer a new generation of super kits; aluminium cylinders with machined heads, pistons with high silicon content and wire rings. These are more powerful with great potential for further modifications and are made by the likes of Quattrini, Parmakit, Polini or Pinasco and the range is still growing.
BGM have presented a prototype of their own tuning kit at this year’s Scooterist Meltdown which features all of the above plus BGM’s obligatory selling point; value-for-money. It is the only kit offered for less than 300 Euros, but does cheap also mean cheerful in terms of performance?
To answer this question German Tuner Dietmar Mauerbauer of LUZ Racing tested it against the strongest kit in the 177 cc class, the Quattrini M1X. Out of the box both kits are designed for torquey engines and for the purpose of touring they should ideally be run with a box type exhaust and a slightly enlarged inlet with a Dell’Orto SI carb of at least 24 mm or a larger round/flat slide carb.
For his test Dietmar used a PX 125 engine with a standard 57 mm stroke and a moderately modified inlet; it now opens at 116° before top dead centre and closes at 58° after bottom dead centre. He also used a PHBH 30 Dell’Orto carb since it offers more flow capacity and better adjustment over the SI range. The exhaust is a Big Box Touring by BGM. The ignition system remained standard.
The results are quite impressive for this level of engine mods and budget involved. The curves look similar with the exception that the BGM 177 kit (black curve) produces slightly more power and torque than the Quattrini M1X across the entire rev range. Peak power and torque figures are 19.8 bhp @ 6366 rpm and 22.5 Nm @ 5762 rpm for the BGM compared to 19.1 bhp @ 6274 and 22.1 Nm @ 5645 rpm for the Quattrini.
To give you an idea how this translates into the real world: The torque of the BGM barrel at only 3,500 rpm is what a P200 produces at its peak. Top torque is 22.5 Nm (16.6 ft lb) @ 5762 rpm which is more than 40% over that of a P 200 and not too far off a GTS 300 with 23.8 Nm (17.5 ft lb). The peak power of almost 20 bhp is roughly double of what a P200 kicks out at the back wheel. With uprated gearing this scooter should be capable of 75-80 mph and travel at 65-70 mph all day.
Since both barrels can easily be ported and stroked they offer excellent opportunities for tuners. Being relatively new on the market there are no examples for the BGM barrel in high states of tune but German tuners have already achieved 50 bhp with the Quattrini!
To summarise, the 177 cc BGM ali barrel has been demonstrated to have a good price/performance balance. With comparatively few modifications you could build yourself a low maintenance large frame Vespa that is cheap to run and therefore suitable for everyday use and touring, yet offers outstanding power and torque. At the moment it is too early to comment on reliability, but with a cast piston from a reputable manufacturer things look positive.
Marcus
Specifications compared
BGM 177 (street price €300)
- Ceramic plated aluminium barrel
- CNC machined billet cylinder head
- Bore 63 mm
- Stroke 57 mm
- Capacity 177 cc
- high silicon cast piston with two 1 mm wire rings
Fits all 125/150 3-port largeframe engines:
- Vespa PX125, PX150
- Vespa Sprint 150 Veloce
- Vespa GTR 125
- Vespa TS 125
- Cosa 125/150
Quattrini M1X 172 (street price €430)
- Ceramic plated aluminium barrel
- Cast & machined cylinder head
- Bore 62 mm
- Stroke 57 mm
- Capacity 172 cc
- high silicon cast piston with two 1 mm wire rings
Fits all 125/150 3-port largeframe engines:
- Vespa PX125, PX150
- Vespa Sprint 150 Veloce
- Vespa GTR 125
- Vespa TS 125
- Cosa 125/150
hp nowhere near that in vespa 125 bit febs scootering
please please can someone tell me what size jets to use in a 30 mm delloto on a bgm pro 177 ,60 mm crank open inlet port opend transfer ports to 1,5 bgm gasket , we are have trouble at high revs got in running only doing 2,, 4 000 rev it wount pull afther that it seems as if it stariving for petrol DONT GET ME WRONG THERE IS NOTHING WRONG WITH THE BMG 177 PRO please please can some one help me THIS A GENIUE REQEST thank mark finney ,england newcastle under lyme
May well be starving of petrol. Did you fit a fast-flow tap? Checked the petrol cap breathes properly? Best bet is to get the scooter on a reputable dyno.
Can you please tell me what jets you used for the 30mm Dellorto phbh I’ve got a similar set up but I’m a bit stumped???
thanks sticky just had all the right jets sizes emailed to me from germany we where way out i was only on a 118 ,,silly me but now i no the right sizes atom,, needle and idle ,thank god
Shame the BGM kit is no longer available 🙁