polini 208 low on torque

[ssteam177]

having just dyno'd my scooter last week and looking at some other figures of others with polini 208 kits i was wondering if anyone can give me a few ideas as to why mine doesn't seam to have the same amount of torque and to why mine seams to make its power higher up the rev range 6000 rpm to 7500 rpm? and more than likely for the snapped dykes ring that was spat out of my exhaust port yesterday on the way back from my clubs over night run. ive ordered the gran sport twin ring piston with no dykes ring to hopefully fix this problem. i also have an mmw evo 2 reed block to replace the malossi reed block.
any ideas to help would be most apprecitated
thankyou in advance!!!!!!!!
the dyno sheet and specs are in the vespa dyno graph section

here is my polini 208, bgm pwk 30mm mikuni vac pump
maz 60mm reed valve crank
23/64 up gear with t5 4th
malossi reed block
pk flywheel
cases welded and reported to suit the kit
exhaust port widened
.8mm packing plate on the bottom of the barrel
mmw 10.5;1 head
vintage 226 hot wing pipe
the set up is not as torquey as i hoped it would be copared to the other dyno sheets ive seen with the polini kit im unsure why
http://i40.photobucket.com/albums/e241/ ... 153616.jpg
ps sorry for the s**t image scaner is not working taken with mobile

[ssteam177]

it wasnt a snaped ring but the piston skirt snaped off below the transfer window and the barrel cracked below the transfers also. the engine has only done 750 miles.
although i have a spare polini barrel and piston i think i will give a malossi a try this time

[Diablo]

Crikey cracking the barrel spigot as well. That can't be easy to do!
Struggled to read your dyno graphs but yes it does seem a little down on torque.
I see you have split the difference regards pack plates as well which should have by rights gave you a torquier set up.
One of the great benifits of the polini kit is its masses of torque so I can see why your dissappointed.
I do wonder though if there weren't some underlying problems with the set up being as the piston has let go so badly.
The piston breaking where it has is classic polini but with the old type pistons not the new 2 ring ones. Its the main reason they fell out of favour for so long.
I'd go back and check evrything regards your set up and see if you can find a cause.

[ssteam177]

I think the reason the barrel spigot cracked was due to me maybe not leaving enough meat there when i matched the piston to the barrel as i opened up the transfers on the barrel leaving 10mm from the bottom of the transfer window to the bottom of the barrel.
I think the kit didnt last due to the power being made to high up the rev range 6000rpm to 7500rpm? I was going to try a jl pipe to see if that helped with the torque but i didnt get that far. I 'll post a few pics of the damage tonight once ive pulled the engine out as ive only taken the head and barrel off to see the damage

[ssteam177]

here is my pistonhttp://i40.photobucket.com/albums/e241/ ... 150338.jpg

[ssteam177]

Any ideas to why this happened?? Ive striped the engine down and had the crank checked everything looks good