GTS OWNERS CLUB

old mod · troop Joined: 31 May 2007 Posts: 27 Location: Auckland, NZ

Sorry if its obvious but can you get away without an electronic mixture gizmo if leo vinc and polini variatoring a GTS.

Can the standard piaggio dealer tuning be set a bit different to accomodate the performance backpressure difference?
Ta
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Was at Brighton '62, always ridden my scoots everday from then on, beginning to think I have a slight problem!

Maver · Posted: Fri Jun 27, 2008 9:10 pm Post subject:

loads of people run a polini variator and a leo vince (or PM / scorpion / other pipe?) without adding the expensive electronic gizmo mixture masher box.....

has someone suggested you need it???

best thing is fit new pipe, disconnect battery for 5 mins, re-connect battery, let scooter idle for a good 10 mins to allow the sensor to adjust the mixture to suit the pipe.

as for the variator just find out what rollers folk on here are using and have a play Wink

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suit scoot · Posted: Fri Jun 27, 2008 10:20 pm Post subject:

14g rollers are the sex. i ran 14.7 for ages to gain more top end but its crap off the line. 14g is just right for me.

but i'm a rake.....
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revolution deathsquad!

old mod · troop Joined: 31 May 2007 Posts: 27 Location: Auckland, NZ

Maver and Scoot. Yes I got impression engine is set too lean on factory settings and richening up could aid longevity.
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Was at Brighton '62, always ridden my scoots everday from then on, beginning to think I have a slight problem!

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

No the engines not running lean, its lambda controlled fuel injection so its running as close to the ideal stoichiometric ratio which is 14.7:1 air to fuel... this is the same ratio that all lambda systems use, car bike etc etc.

The plug in gizmos are there to enable the injection system to cope if you move parameters outside of its adjustable range...

There is also a minor improvement in performance by running the engine slightly richer especially when under acceleration... but its marginal on a std engine...

old mod · troop Joined: 31 May 2007 Posts: 27 Location: Auckland, NZ

So to recap Cheeky.

Put Leo on ,allow battery disconnect as Maver says, and ride.

As a side issue on MV forum a dyno test reckoned the gizmo box could have been worthw a small power increase, so really we are saying then its a power thing not a safety thing for temperature and thus not a necessity? Right?

Thanks for input, always like seeing your helpful posts. Thats for real.
Old Mod
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Was at Brighton '62, always ridden my scoots everday from then on, beginning to think I have a slight problem!

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

Yes the power box is purely about trying to get the most power from the machine, the standard fuel injection can cope with an exhaust no problem at all.... and the variator kits have no effect on fueling anyway so they are fine. Wink

aa-gts · Posted: Sun Jun 29, 2008 9:36 am Post subject:

"No the engines not running lean, its lambda controlled fuel injection so its running as close to the ideal stoichiometric ratio which is 14.7:1 air to fuel... this is the same ratio that all lambda systems use, car bike etc etc.

The plug in gizmos are there to enable the injection system to cope if you move parameters outside of its adjustable range..."

I see big words but have no idea what they mean Confused

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

Haha... big words from my small mind Laughing

Basically the ideal air to fuel ratio is 14.7 to 1... this gives the best possible burn and its known to boffins as the stoichiometric value.

With modern fuel injection including the GTS in question, they have a lambda sensor fitted into the exhaust that basically works as a nose for the engine management and continually sniffs the exhaust gases, if it finds a weak mixture it tells the ecu to inject more fuel, if it finds a rich mixture it tells it to inject less.... and it does this all the time many times a second to always try to stick to the 14.7 to 1 ratio.

So even if you swap the exhaust for a performance one, as long as the lambda sensor is still fitted, the injection system will keep the mixture correct the best it can...

aa-gts · Posted: Sun Jun 29, 2008 10:53 am Post subject:

I'm getting a Scorpion Pipe fitted next week, do I take then, from what I've read on here, that the dealer fitting the pipe should go through the whole disconnect battery routine without needing to be asked and that there are no other adjustments to be made - as opposed to the rigmarole surrounding a new pipe on a two-stroke engine?

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

Spot on correct...

You dont have to disconnect the ECU it just speeds up the process, the ECU learns quicker when its freshly restarted thats all.

buddyphil · Posted: Sun Jun 29, 2008 11:30 am Post subject:

aa-gts · Posted: Sun Jun 29, 2008 11:37 am Post subject:

Thought those problems had been sorted on the newer version?

Chose a Scorpion over a PM as I have had a bad experience with PM Pipes (and the people who work there) in the past - had brand new PM on my PX210 and it rusted through within ten months despite being coated by PM; when I phoned to complain they didn't seem to give a toss and, hence, I wouldn't go back to them ever again.

As for the other pipes available for the GTs, what would anyone recommend over a scorpion then - other than a standard Piaggio replacement pipe?

Maver · Posted: Sun Jun 29, 2008 12:34 pm Post subject:

i think the PM has proved itself on the GTs, comparisons with PM pipes for 2 strokes is like black and white, 2 stroke pipes being mild steel (needed for them to work correctly) and the 4 strokes being stainless and therefore more durable.

true PM tuning have a reputation for shoddy after sales service "race use only, 3000 miles is a lot of races" being their usual reason for what we consider early failure Rolling Eyes

however if the pipe works and lasts, which the GTs PM version seems to so far, then there's no need for after sales service Cool

i do hope the newer version of the GTs scorpion is better than the original, at least that way there will be another pipe to consider using.
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monty9120 · Posted: Sun Jun 29, 2008 6:12 pm Post subject:

the only difference with the new scorpions is they have added another strap

which makes them look shit anyway Laughing

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