Modern Vespa

Hi is it possible to combine the Dr Pulley Clutch with the j costa?

I expect so - but the silky slow-speed manouvering may be compromised. The HIT clutch is designed for a rapid positive take-off (think racing) not for all-round utility.

I have read that before, but what does that mean? Is is not possible to ride the city anymore?
does it have inpact on topspeed?

No change to top speed. Riding very slowly in the city wouldn't be as easy, if I've understood the descriptions of the mechanism correctly. If you did adjust the HIT clutch for better slow-speed stuff, then you'd be losing the whole point of fitting one, which is to give you the best possible WOT take-off.

The stock clutch is a reasonable compromise. Not perfect, but that is the nature of compromise.

Jim do you have a better suggestion for more take off power?

btw:
I read on a dutch forum it is possible to get a cilinder of a X9 with that adjustion you get 460 cc instead of 400 (in my case) or is that bs?

The x9 (500 cilinder) has 40 pk thats 4 more than the mp3400.

You'd have to check with cheekythomas if it is reasonably possible. Of course anything is possible with enough money. Personally I wouldn't dream of doing it, there are so many ramifications.

Better take-off by altering the clutch directly adversely affects smoothness in take-up. So up to you which you want. If you rarely have to do slow manouvers or never filter through traffic, and just want to be first away from the line - change the clutch.

If you want more power, faster take-off *and* smoothness and you already have the modified 400 J Costa bell then by far the cheapest and most pain-free way is to chop in the 400 and get a 500.

hmmm is the 500 so much faster than a 400?

thanks for the advice btw

Not according to the specs Piaggio supplies in their brochures. Almost the same. Top speed anyway. Not sure off the line to various speeds.

Top speed on my 500 was 95 (GPS verified). Strangely, lower top speed now I have a larger diameter tyre on - I think that even with the J Costa the bike just can't get over some power hump. Downhill might help here.

The stock 500 is for sure faster off the mark than the 400 - as is the 250!