Scooterotica

I've been running an RT225 with an open mouthed 28mm dellorto, JL exhaust with standard Indian GP200 gearing. Got no complaints ! regularly does well over 70 with the set up that I have . It delivers its power effortlessly, a joy to ride. Used it for the Euro in Austria 2015 with no issues from the kit. IMO a quality and quick touring kit that returns a surprisingly good MPG. Just finished building the engine for my current project and its also an RT (195).

What about a large capacity old school kit? One using a Japanese piston conversion. Are these kits still available / viable?

Yep but the more tuning you look towards, the more you remain in the realms of revs = power, rather than very limited tuning and simply a capacity increase.

One of the best conversions out there is the Suzuki TS250 piston conversion with an Ape rod or a.n.other rod that has 18mm gudgeon pin to suit the TS250 piston. Harry Barlow produces kits with a different rod to give the same result. The new Richard Taylor cranks have a suitable rod with 18mm gudgeon pin too. The Mitaka TS250 piston is cheap and fantastic quality, with quality alloy and rings that put Lambretta pistons to shame. 60mm stroke is an option too and should be considered when thinking about port work. Remember that 'tuning' may actually be working in the opposite direction to the stump-puller power delivery that you're looking for so don't think that BHP is your end result, rather it is about spread of power.

I've run a number of TS250 conversion motors and the current 18mm gudgeon pin, long rod, 60mm stroke cranks out there mean that it is a spec that is probably a better option now than it has ever been.

Adam

Avanti
NK road
30mm delly
107 crank
AF 6 plate clutch
Static @17 degrees.
All simple stuff.
Can and does run flat out all day long.
GPS'd at 80 ( the pipe stops it going any faster).
Pulls up handcross hill at 70+, steepest hill on the A23 to give you an idea my work van rolls down it at 80mph

And as Adam says change the pipe and gearing and its a different beast.

10 inch Terror wrote:What about a large capacity old school kit? One using a Japanese piston conversion. Are these kits still available / viable?

At the risk of sounding like I'm giving a clevercunt answer, and having the thread locked, what about an iron 200 with a fettle by someone who knows what they're doing? Keeping the capacity at 200, rather than 225, should keep it from being overly vibey too. All the parts are easy to find, in that it's just a piston you'd need to buy.

Muttley McLadd wrote:

10 inch Terror wrote:What about a large capacity old school kit? One using a Japanese piston conversion. Are these kits still available / viable?

At the risk of sounding like I'm giving a clevercunt answer, and having the thread locked, what about an iron 200 with a fettle by someone who knows what they're doing? Keeping the capacity at 200, rather than 225, should keep it from being overly vibey too. All the parts are easy to find, in that it's just a piston you'd need to buy.

With the same risk,
How are you going to develop the power.
Stage 4 Is about as wide as you want to go on the exhaust, lift it and you getting revvey, which the OP doesn't want.

Jazzy wrote: With the same risk,
How are you going to develop the power.
Stage 4 Is about as wide as you want to go on the exhaust, lift it and you getting revvey, which the OP doesn't want.

That's all I was thinking. A stage 4 200 with a can (that's not revvy) or a well made clubman, although not going to set the world alight with performance, would be easy to ride if you're not in too much of a rush. And, so long as the tuner doesn't try to make the exhaust port big enough to fit his fist through, should be pretty quiet too. The tuning wouldn't cost a mint, and if/when it goes bang with hamfisted use, it wouldn't be another trip to the mortgage broker for a rebuild.

I had an Indian case with a Spanish 200 barrel,
The combination altered the deck and port heights which ment without gaskets I had a squish of 2mn.
30 delly and an under kick start fresco .

It Was a dream to ride. But then the Arms race started and it got left behind by newer kits.
And my requirements changed with Euros being my main thing cruiseng at 65+ what ever the wind or gradient became a minimal requirement

I built an engine using the BGM RT225 kit using a 660/110 crankshaft and Jet gearing. I had MB do the reed set up for me and take a good look at the cylinder and make some changes. I put 12 miles on it around town before heading out on a 1100 mile 2-way trip to Pasedena and the LCUSA Jamboree. Still going strong 4200 miles later, much of it highway miles at speeds upto 80mph. The highest rate I've had it has been 85mph - but it is really pushing it as far as it will go. A very affordable price on the BGM RT kits so that I could afford to have some work from a pro shop.

I think it's between the Avanti and RT at the moment. I'll dig a little deeper into both I think. Thanks for your help fellas.