Part 3: Catching up on SLUK Projects – Quattrini M210

Back in 2018 I imported this very original, one owner from new Spanish Lambretta Li 150.

It was at this time that the new Lambretta small block Quattrini M210 kit was released. Having bagged an early test ride on the Chiselspeed demonstrator I knew instantly what my engine choice was going to be.

I’d already got the scooter an MOT and UK registration plate by this stage and sent it off to Chiselspeed to be brought sympathetically back to life. They rebuilt the motor from vapour blasted casings with a new Quattrini top end and all the internals needed to cope with the extra power. I also had a front disc and BGM dampers on it, plus a bit of powdercoating. Other than that the bodywork was left as it was, even the cable outers are still the original ones. It’s tatty but I like it that way.

I’m not very mechanically sympathetic (well, I like to enjoy my riding at least) and have a reputation for blowing things up. That first kit didn’t last me 500 miles. I killed it riding back from Tenby in 2018 (click the link to watch the video). Chiselspeed rebuilt it with a new top end (not cheap) and I rode it to the Spanish Euro in Abejar, then on to Ibiza and back with no problems, other than a persistent misfire which turned out to be a dodgy flywheel.

Not long after that road trip, I killed it again, although I don’t accept any (or at least not much) blame for that episode. The crank melted on the motorway on the way back from Exmouth. I’d been sitting at a decent motorway speed thinking ‘what a fantastic engine this is’ for about 50 miles when it went bang.

Third time lucky?

It went back up to the lads at Chiselspeed for a new crank and top end. Whilst it was there they also fitted a Koso EGT gauge and SIP speedo for extra safety. They also lowered the compression slightly. The Quattrini can run quite hot and sitting for long periods with a wide open throttle isn’t good for a two stroke engine. I ran the engine in and with the EGT and head temp gauge was able to see what the engine was doing. It was surprising how quickly it was getting overly hot on a wide open throttle. The EGT is like a constant reminder not to get too giddy but it was spoiling my enjoyment as well.

2021 SLUK Cool Flow

It was around this time that Sticky’s Lambretta Kit Book was released. One of the things he’d done for that was to modify a head cowling to provide more airflow to help keep the Quattrini a little cooler. I decided to look into having them made. The first fibreglass prototype was moulded and fitted to my scooter within a couple of weeks. The cowling certainly works, it lowered my max running temperature from 628ºC to 597ºC. The plan was to have a few made to sell but sadly the manufacturer was too busy to make them and they never materialised. Whilst writing this article I’ve given him a nudge again, so maybe we will realise that project soon.

Belgian Euro

Obviously, 2020 and most of 2021 had been written off thanks to Covid but things were a bit more normal last year. I used the Quattrini for the Belgian Euro in June and spent a few days touring on it before the rally.

As we headed along a Belgian dual carriageway about 15 miles from the event my curly CST 10 exhaust decided to crack – big time. It made one hell of a noise but I decided to carry on at a lower speed and get to the rally. If you were on site when I arrived you will have heard me arriving! An unsilenced Quattrini is VERY LOUD! A quick look under the scooter revealed that there was nothing left to weld, most of the exhaust had dropped off on the road. The one disadvantage of having something that’s not a typical Lambretta setup is that you can’t just buy something to fit as easily as you could with a TS1 or RT. There were hardly any stalls at Euro Lambretta and I was forced to send the scooter home in a van and ride back on the missus’ RT225.

New exhaust

Due to various factors, I didn’t get around to buying a new exhaust for the scooter until just before last Christmas. I opted for Darrell Taylor’s version of the JL Race. He’s made quite a few improvements to it, especially with the exhaust flange. I had it powder coated at a local place in ‘high temp’ black after the New Year. With the exhaust fitted, I headed down to see Al at Diablo Moto in Nuneaton to check the jetting on his dyno. The ‘high temp’ powder started to bubble during the first run!

Fault finding

What should have been a quick dyno session turned into one of those full-day jobs as we tried to find an ignition fault that showed up on the dyno. It turned out to be the MTECH box. Rather than simply replacing the mappable CDI/ignition coil I decided to swap the whole ignition system.

We also discovered the reedblock had started to split so that was replaced. The old one will be bodged as a ‘get me home’ spare.

SIP Vape

The SIP Vape has proven to be reliable, with good power and lighting characteristics. Plus the Vape is easier to get if you’re riding abroad and have a problem. So Al fitted that and we set the scooter up on the dyno last week. We’ve done some video showing how we fitted the Vape so will do an article on that at a later date.

Dyno talk

On the dyno at Diablo Moto, my scooter was down on power around 4,500-5,000 rpm, just at the point where you need the torque when riding to rallies. I’d been feeling that on the road as well before the exhaust broke in Belgium so we may need to investigate things further. The scooter had a set of new rings just before the Euro so I don’t think it’s that. The only other difference is that we’ve swapped from variable ignition to static. Even so, the engine is still making 25.2 bhp and 19.3ft-lbs of torque.

Diablo Al explains his Dyno findings, “Where you are most noticing the lack of power is at 5000rpm and this is where you are spending a lot of time when riding in a group. Another customer is running the same pipe and his has an extra 2.5 hp over yours here which is key. The difference at 6k is noticeable too”.

Road test

After spending a bit of time setting the scooter up for the new ignition and exhaust and having done a couple of road tests (see video above) we swapped the timing over from 17º to 19º and lowered the main jet from a 142 to 135 and I went out again. This certainly improved the performance, the engine temp was well within safe limits and the jetting was still ‘safe’ on the Dyno. Al was happy to leave it at that.

I’ll be using the Quattrini for Scarborough at Easter so will see how it performs then.

Summing up

I’ve had this engine for five years now and paid for it with my own cash. Aside from the early teething trouble, it’s been amazing since the third rebuild. I’ve covered 6,100 miles since then. Even in the early days when I had problems I still loved this engine. Given the choice of any small block kit, or any of the mainstream large block 225 engines there is absolutely no doubt that I would choose the Quattrini M210. It’s an outstanding engine. It’s fast, useable, good fun, doesn’t use much fuel (comparable to an RT225) and aside from my heavy right wrist has been reliable since 2018.

If you have a small block engine and are wondering what to do with it, I suggest you go for the Quattrini M210. You won’t regret it.

Thanks to Al at Diablo Moto for help with this article.

Iggy