branshano666 wrote:Hi there I have recently purchased an mz saxon soortstar 125cc 1997 at the moment it is only capable of 65mph with 3000 rpm to spare the bike wont push any more and 65 is the speed down a hill I only hit 60 maybe 61 on a straight any advice on how to derestric if possible would be appreciated
That's about all you're going to get out of it. Forget any thoughts of derestricting it as it's not restricted, but you'll not get any more performance unless you spend more than the bike's worth. The ETZ125 motor will pull around 7000 rpm, no more. You'll never see the tacho all the way over to the right, the engine isn't designed to do that. Design top speed is 100kmh (63 mph) on the flat.
Don't forget that the speedos on small Japanese bikes tell massive lies - a "mate on a YBR125" isn't really going any faster than you are, even if his speedo says 75.
Depending on your weight, you may be able to get it up to 65 on the flat if you tuck down behind the nose fairing. New plug, new air filter, check the timing, cleaning out and setting up the carb properly will get the most out of the engine. Decoking the exhaust pipe may help - a "sports" pipe definately won't.
If you've passed your test, an ETZ150 top end (try ebay.de), bolts straight on.
However - the best way of going fast on an ETZ or Sportstar 125 is to buy the best tyres you can afford (try a Michelin Pilot Sporty on the front), change the fork oil, service the brakes and learn how to take corners quickly without dropping much speed. There's not much that'll keep up with a well sorted MZ around the twisties.