Tuning options for 200cc engines using the Monza kit

We were recently shown one of these kits by a customer of ours who had bought it to use on a scooter he was building for his girlfriend.

Not many of these kits have been sold worldwide so there isn't a lot of feedback available on how people are getting on with them. They have been launched into a market that is already full of barrel kits with long histories, both good and bad.
There are hundreds of cast iron, TS1 and Rapido barrels in use.
It seems that the Monza kit is aimed at the middle of the road touring type engine but it's price is comparable with the TS1 kit so pound for pound it doesn't seem like such a good idea.
Having said that, it opens up options to use smaller carbs thereby helping with fuel economy - at the expense of a little top end power.

On examination of the kit it appears to be a direct copy of the TS1 200cc barrel, but with the different, slightly smaller reedblock.
The manifold supplied is either an alloy or rubber Imola type manifold, which we looked at on the Imola page.
The piston is a 66mm version of the later type Imola piston, which is lasting OK by all accounts.
We are told by Tino Sacchi that he plans to "beef up" the Monza in the same way as the most recent Imola barrels (more area on gasket face for big transfers and boost port, more metal around the transfers for doing big race style transfers).
When these "beefier" versions are available there is a strong chance we would choose them over the TS1 barrel for making the "big" barrels we do (71mm with Japanese pistons and stroked cranks) as all the improvements which have been made will make our life, as tuners, easier.
There are apparently three versions of the monza kit - 200cc, 210cc and 240cc.
The 200cc version is the one we have discussed above and has a bore of 66mm and uses a crank with a stroke of 58mm (i.e. most cranks around).
Then there is the 210cc version which is still 66mm bore but needs a crank with a 60mm stroke.
We don't know if this is the same barrel as the 200cc one or if it is taller to allow for the stroked crank. Lastly there is the 240cc version which has a 70mm bore and is for use with a 60mm stroke crank like the 210 version.

Our concern is primarily with reliability these days - we've done super quick but now it is all about reliability.
We are worried about how well these 60mm off the shelf cranks will last - they are harder to use as you sometimes have to use pack plates and recessed heads.
Added to that the fact that many scooterists will still fit a kit and not check the squish clearance there is the potential for problems.
Many will take this as us being negative again about someone elses product but we are trying to be objective and give useful advice.

To help you decide about a Monza barrel please look at the table below for a summary of our thoughts on the kit.

	Pros	Cons	Questions to ask yourself
Monza 200 66x58mm	Better fuel economy than a TS1 due to use of smaller carbs. Better piston than TS1 200. Can keep 28 or 30mm PHBH if you've already got one.	Pound for pound more expensive than a TS1 200. Numbers sold mean little feedback at present.	If I am making the jump to a reed valve barrel is the Monza the one I want? Or should I look at the TS1 225?
Monza 210 66x60mm	Stroked crank means more power.	Possible reliability/setting up problems with 60m crank. Stroked cranks normally make the scooter vibrate more.	If I am going the hassle and expense of fitting a 60mm stroke should I jump straight to the Monza 240?
Monza 240 70x60mm

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