Max speed ST70

Hi all,i bought an ST70 from 1992 and the bike's engine doesn't start in the first place,than we cleaned the carby and now she drives good but the max speed is 55 Km/h is this normal?

No, that's a bit too slow.
She should do 65km/h at least.

Most likely it's the ignition timing.
Followed by air filoter, valve cearance and timing, spark plug.

make sure to fit a fuel filter, especially if you have the metal gas tank.

There is no fuel filter the carby is an keihin pc05,and my gastank is metal,i changed the front sproke from 17 to 15 the back is 35.now the speed almost 70 is this the top? Because i think 90 is much safer to go allong in the traffic.
Ignition timing:how do you do That?there is only à black box witch controls THE sparks i think.


P.s:sorry for my bad english,but i am so in love with my st70 That i do anything to make here ride perfectly,even making me ridiculous.

Because there is no fuel filter, you should install one. Just an in-line filter.
They come very cheap and are very helpfull.

70 is about pretty much the top speed, yes.
If you want to go faster, get in touch, I can do some tuning for you.

A black box? So you have a CDI 12v ignition?
What's written on the flywheel?

Idd it is a 12v but i don't now witch parts are original,the bike was bought by a man who set it in his home for decoration i will look this evening watt is written on the flywheel.

Alsow i read here that everyone has a chasisnumber starting with st50 or ST70 mine starts with DB01 and than a number there is no st in my number.

Now i see you are from belgium cool i sent PM.

I am still not getting any more than 35mph absolute max which is with the engine screaming uncomfortably and I am sure it will not rev any higher without blowing up..... I did change the drive sproket to 15 teeth and aside from that ,everthing is 100% original 6 volt from 1979.

Can someone explain the valve clearances? I have feeler guages but I don't know at what point in the compression cycle to measure it and what the gap should be. Also any other clues to speed it up without changing the original engine parts. Plug seems OK and clean and the points too, maybe confrm the clearance on this too? Just curious why it won't go a little faster, 30-35 is too slow in general traffic and I am fed up hugging the kerbs being overtaken by everthing except bicyles....

Thanks

Set the valves at 0,05mm when the engine is warmed up.
Flywheel should be in position 'T' when checking.
Checking the spark plug gap and the points gap is always a good idea.

35mph is too slow for a full Honda 70cc engine.

Thanks Waynus, I will try and check the setting at the weekend. 40mph would be fine a be a safer speed to go any distance.