So was I 8) so I bought and install J COSTA less then month a go (you can see my write up here http://www.modernvespa.com/forum/topic47985?highlight= )
My expectations were quite high and I could not wait to try it.
Liked it... it was definitely an improvement but it was still not exactly what I was looking for. Acceleration 0-20 MPH did not improved at all. The revs stayed quite low (3500rpm) between 0-20 exactly the same as with OEM variator. 20-90 MPH smoother and quicker than with OEM variator but it never hit 7500rpm as jimc said his Fuoco can do with his J COSTA.
So I ordered Dr Pulley stuff. Sliding Rollers of 15g,16g,17g + HiT clutch. It arrived on Friday.
First Hit clutch went in so the set-up was J COSTA + HiT and then I went for a ride. Immediately when I took off I though oh my GOD this is so smooth. The clutch just bites instantly and there is no vibration what so ever. It was smooth but again the engine was not reving as high. This was most probably down to weight of the J COSTA + weight of the HiT as they are both noticeably heavier than the OEM parts.
Next I took COSTA out put my OEM variator in with 15g Dr Pulley sliding rollers and off I went.
No shudder, No vibration, Acceleration 0-20 MPH improved, 20-90 VA-VA-VOOOM, Throttle response excellent and Smooth as silk all the way up to 90MPH
Feeling that I could still do more I changed the clutch spring for harder one (25kg Pink) and the overall result is UNBELIEVALBLE !!!!!!! The power is brutal and instant. It was a first time I got scarred on the scooter doing WOT It is a totally different machine now.
Now I am not done with it yet, I am still going to experiment more with the springs and rollers. For now I am keeping it as it is !!!!
If you really want to improve your MP3 400 get Dr Pulley stuff. You will have much more options to choose from in terms of tuning it the way you like it (HiT clutch has 2 different sets of springs so you can change both for softer or harder + you can try different weighs of sliding rollers). I know there is a lot of fans of J COSTA but I can only report my experience and findings. Also note that the MP3 500 could be slightly different story.
OEM clutch + J COSTA = £230 for COSTA ....there is just one set-up option, no weights for variator other than 23.5g it's shiped with. There could be different clutch springs available somewhere but I doubt that would help cos the clutch just slips to much.
HiT clutch + J COSTA = £255 + £230= £485 ....bit expensive but and not the best in my opinion.
HiT clutch + Sliding Rolers = £255 GBP + 40GBP = £295... maybe 10 different ways of set-up to fit you riding style. I am really amazed with this and it beats J COSTA (on its own) hands down!!
I am sorry for my English it's not my mother tongue.
EDIT: Going home today through a lot off start and stop traffic I experienced quite a lot off vibrations at take off. This should be due to clutch (push pin) biting too early. Manual recommends changing to harder clutch springs and/or harder pillow springs. I already have the hardest clutch springs on but softest pillow springs. Will replace the pillow springs for harder ones asap and will report back... So don't take my above set-up for final please. 8)
EDIT 2: OK so "Clutch Springs" need to be Pinks (25kg) and the Pillow Springs" Yellows (20kg) + Dr Pulley SR (15g) in your OEM variator . This is my finall set-up ABSOLUTELY LOVING IT !!!! That grin is getting so wide that I have to pick flies from it
⚠️ Last edited by joe bulva on Wed, 08 Jul 2009 18:01:01 +0000; edited 5 times