malossi help

1st post for a long time sorry, has anybody else built a malossi 210 motor which cant pull the skin off custard ? i have a 210 kit , centre plug head, race crank , upjetted carb, matched casings, cut piston windows, polini exhaust ( i know),t5 4th. Its not bad but its not good either. Very lucky to get 65 plus unless downhill. windy weather kills it stone dead. what have i done wrong , any ideas? (or am i just too fat )

Your Polini won’t help you at all, except you rev like mad, try getting a decent pipe like taffspeed, pm or sip.
Bigger carb as well. This should help you out in the first instance.


Thanks for the answers , i will have to bite the bullet and get a tidy expansion . i have a feeling that my squish band is too big therefore not enough compression perhaps (about 1.5mm). If i do up it , do i jack the barrel up or skim the head or no gasket? this is where i start to get a bit confused to be honest , any help welcome.i have access to a machine shop. Hitman are you saying the stainless exhausts are no good ? as pm tuning seem to suggest.

My 210 with matched casings, modified crank, sito plus exhaust, would pull between 60 and 75mph on the flat depending on conditions and I weigh about 15stone.
I was disappointed with mine originally and expected more, a couple of my friends were running standard T5s with expansions and it was no better top end than the T5s.
Make sure everything is set up right though and check plug colour at full revs if its running too rich it definitely wont help top end power, be very careful though if you down jet, too much and you might seize the kit.
The exhaust does make a big difference though as it is now fitted with a scorpion and will pull between 60 and 80+mph on the flat. It starts pulling at about 70mph now!(T5 4th], but its just as bad into the wind. It runs much hotter with the scorpion though and that brought other problems.

   Hope this helps