You can turn a400 in to a 500 very easy just change the cylinder and it becomes a 486cc with 41 HP

its also possible to change a 250 into a 400/500 its need some more then a engine cableharness, throttle body and a swing arm + mounting brackets for the frame
Jah wrote:
But the combustion chamber's volume is larger, thus the mixture will be leaner. Those things do not have a mass airflow sensors, so the ECU does not "know" it should add more fuel.
it will learn it self
Jah wrote:
Nope, it won't. Lambda probe works only on middle revs.
It will, i have done it dozen of times even tested it on a dyno a stock 400 has 23.7 hp on the rear wheel a 486cc 34.x hp a stock Fuoco 500 (492cc) 34.6 hp and the mapping of a 400 and 500 are the same
Jah wrote:
Well, if the maps are the same, that means that either 500cc works lean or 400cc works rich. There's no third option, because that means that they get different amounts of air per same amount of fuel.
Different injector
Jah wrote:
Nope, both 400 and 500'2011 use 8720235. But the ECUs are different (504680/CM078510 for 400cc, CM085503 for 500cc), and given they're the same by hardware, their only difference is firmware.
Eh don't forget the twinspark a 492 is a twinspark the 399 and 469 are single sparkplug

and yes injectors but the non twin spark like your big Beo or a X9 the 469cc simply exchange the top part from the 400 injector because there is no return

and your right a 2011 is running leaner then a 400 it did came with a firmware update after a year or so it started running 200 rpms higher then at about 1700 rpms at idle then, but using a injector of a x9 will also give it a different mixer

There was also a update for the 400 in 2010 due the the stalling and backfiring and you can upgrade the firmware of a 400 ecu to a later 2012 500 ecu but it runs better with a x9 injector if you want to spend more, and now i'm thinking about it i will try the x9 injector some time when i got a stock 400 in never tried it

And it will run also with out problems, with out it, got 10+ customers without any other modifaction then the barel and piston it got more bite at lower rpms then the 400 so it will learn and it also show's on a Dyno
It depents on the customer how much they want to spend could be the never updated there firmware never looked in to it

the ones that complained about it after conversion i uploaded the 500 image or fitted a x9 injector but that where only 3 or 4 and one of them did keep having there problems when it was sold to someone else the new owner came to me and did find it eventuely, it was a unhappy fuel relay that did the stalling some how when in use longer is did cut out for a second or so but when you messured the relay it was all fine

I will decline the mods i did to my Fp3 in nov 2009 48 hp due to warranty issues it all most exploded was just in time could save the crankshaft and crankcase but the rest needed new parts and that one did have the 69 stroke crankshaft with the 492 cylinder

the 400's where nothing more then a downgraded 469cc with the same mapping so it will learn that it got more cc its still in the older mapping

With the new 400 HPE piaggio did the same thing it will be update soon i think because its also backfiring there is no regulation on firmware updates in the eu

Some Funny stuff when you look at mappings of the mp3 mui, i believe that it was Winols it will show 4 cylinders where 2 are disabled no mapping and the 2 other will show 2 different mappings when its updated and the same mapping with out update so somehow the 469cc mapping is still in the ecu it al depents on how they flash it i think i never used the OEM Piaggio reader writer

And Sorry for the long explaination

Shortly it will run with out problems most of the time