Suzuki GP 100 I NEED HELP

Hi All I have got a Suzuki GP 100 I bought it as spares or repairs I have stripped the bike down and repainted and got the bike running I have just got the bike throw its MOT and tax the bike the problem I am having I have clean the carb and put in a new Plug and air filter but the engine will not rev above 6000-6500 in any gear under load. It will
rev to over that in neutral I have now run out of ideas and could do with some help there are no air leaks there are no leaking on any of the pipes I live in Chorley if there is anyone that live near me and is willing to help me out I would be grateful I have pulled out all my hair and at my age I haven’t got much

shot in the dark steve....valve clearences?? maybe go up 1or 2 sizes on the main jet would say fueling problem some where down the line disconect the air filter while testing

miffa wrote:

shot in the dark steve....valve clearences?? maybe go up 1or 2 sizes on the main jet would say fueling problem some where down the line disconect the air filter while testing

Thanks Miffa I have had a play with the timing today and the bike sound a bit better not took it out yet to see if it as made any change to the way the bike is running due the good old rain hope to go out on it 2moz let you no how it goes