Scooterotica

Anyone who was interested in the Avanti kit since its launch, may well remember the original long-term test and review we did on the kit. Its a bit of a mammoth read now, but anyone wanting to catch up might want to at least glance through the first few pages to check the port maps and dyno graphs we posted: viewtopic.php?f=7&t=19172

So fast forward a few years and what's happened? Well, Andy who owned the bike had thousands of trouble free miles with the kit and enjoyed it immensely, but times being hard n'all he had to part with the scooter. But the new owner (Alan) has run into a spot of bother.....he has holed a piston and written off the kit! Now I'm not exactly sure what's happened mechanically speaking since we last saw it, but when i stripped the engine for inspection, the ignition timing was 22+ BTDC, so I'm thinking there was an Adv/Ret box on....which has since been removed, but the timing not adjusted accordingly? But that's just a guess, as i say.....I've not seen the bike since we did the original test.

So, having received a new kit from Ron today, i was really pleased to see a few subtle, but very important updates. The head, and piston seem to have remained as they were, cowl cover is now black (which aesthetically i prefer) but the important changes are of course inside the cylinder:

1) Inlet port - timing duration remains the same, but the shape has changed. A much nicer 'softer' shape to the port, which will be kinder to the piston.
2) Transfer port timings look unchanged - same with the rear boost port but the casting looks cleaner inside and directional flow looks slightly better.
3) Exhaust port, this is the biggest change. It appears to be about 1.25mm higher thus giving increased timing duration, and 1mm wider each side, plus the shape/flow is much more angular and pronounced giving better blow-down area. This should bode well for performance, but as always.....the dyno will tell all.

Once we have rebuilt it and run it up, i'll follow up with some dyno graphs.

Old exhaust style:


New exhaust style:


Old inlet:


New inlet:


Kit:


Von Dutch:

Watching this thread with interest

My Avanti TT3 has served me very well over the years and it has been one of the few items that has not given me issue when long distance rallying (exhaust issues, electrical issues, 1 snapped layshaft, etc.) so I've simply left it alone and used it... and used it... and used it. As such, I've not done any 'playing' or tinkering with mine, however, when you consider the after-sale development that other kits (e.g. TS1) have gone through, I'm loving the fact that Ron has kept developing the kit and love the fact that we now seem to have at least a couple of examples that have been further 'dealer tuned'.

I'm intending to pull up a chair and see what you do

Adam

I now have my 3rd kit (still in the box) and will be interested to see the graphs. I've touched or altered the barrels but tried various combinations of exhaust, carbs, gearings, etc..............watching with interest

On a slightly different note....will the Dyno still be available when you head to Fleet Street ?

mick1 wrote:I now have my 3rd kit (still in the box) and will be interested to see the graphs. I've touched or altered the barrels but tried various combinations of exhaust, carbs, gearings, etc..............watching with interest

On a slightly different note....will the Dyno still be available when you head to Fleet Street ?

It's easy to see changes on a Dyno....what different pipes, porting, ignition changes make. But without that visual knowledge, what have you found to be your favourite owner based combination of gearing and components to date?

Yes.......the wheel of steel will keep on turning

I have tried:

Ron Moss Clubman
Franspeed Tourer (not Super)
Franspeed Race

with and without filters
28mm PHBH
30mm PHBH
35 Mikuni TMX

GP 200 G/Box 46 Crown with 20T front and a 19T front (4.6 and 4.8)

Rocco 5 plate clutch
LTH 4 plate with uprated springs

Static ignition
Varitronic ignition
M-Tech ignition

Finally settled on the Franspeed Race, Mikuni 35 TMX with remote filter, M-Tech, 46/19 gearing, 4 plate clutch.

Great for motorway running and nice long straights, economy doesn't change that much unless it's hilly or windy roads then the economy is noticeably less than the clubman and a PHBH. Only negative can be finding the power band when on hilly/windy roads. I recon' i changed gear 4 times more on the C2C than if running 4.6 with the Clubman and PHBH.

You found the clubman so unbearable that the increase gear change and fuel consumption of the Franny was worth it?

My Avanti rides beautifully with a RM clubman on it but I have an early start in the mornings and I had to swap to an expansion with a muffler, otherwise I would still be using it on mine.

Whilst trying different pipes on mine, over a number of years, I've run mine with RM clubman, 48mm VW clubman, Taff / JL3 Road, Micron and Fran Supertourer. The RM clubman probably gave the nicest all round ride, the Taff JL3 gave the best touring performance (static ignition), and the Fran Supertour is what is still on mine now, however, I did have to fit an Agusto unit in order to get back sufficient grunt.

Adam

More the fun factor with the Race

Economy not a massive issue. I think I was getting 12 miles to the litre at best and 9 miles to the litre at worst. Plenty of variables in this though with routes taken and wind/hills, etc. The gear change is a pain but most of my miles are long haul so it's worth sticking with it as is. If I lived in the Scottish Highlands i'd probably think different.

It's also comforting to know you can accelerate from the 60+ bracket and easily overtake, whereas the Clubman will crawl past (maybe a bit unfair, but you know what I mean).

Top speed there's not a massive difference, the Race (+Mikuni) will get over 80 mph whereas the Clubman is more mid-70's. The Race just gets there a lot quicker.

As you know Dan I've Dyno'd the engine as I've changed the bits and it's gone from just under 19bhp to nearly 23bhp....

So mick do you have all the dyno graphs for all your differant combinations or was it done on how it rode?

Got about 3 dyno graphs, there was more but can't find them ! Dan may have some stored on his computer but i'm not 100%