At high revs 7k it seems to misfire and stutter a lot almost bouncing between 7 and 8k but no more acceleration and loses power. any ideas?
That doesn't sounds good. Could be the valves hitting the head gasket or even worse the big end's gone. I remember this problem when engines changed from using leaded to unleaded. The lead would act as a kind of protective coating and prevented pinking and knocking due to the higher octane level.
It did it when it had a 50 block on and now got a mallossi 70kit on still does it but no valves to hit also turned over by hand when fitting 70kit and nothing touches. I am running V Power in it tho
Do you know if it uses rocker arms or camshaft? Rockers were more tolerant but less efficient. V power could be the problem! Best to run on regular. I've heard folks having problems using super high octane unleaded in scoots.
I'd hang tight till someone like scuba or stevep come online and give you proper advice. I'm a bit of a novice to be honest.
What would you recomend? Im currently on an 68 jet and have sports exhaust fitted as well (standard 17.5mm carb)
Ok will give that a go. When i have adjusted the mixture i have been putting idle to 3k then adjusting till the revs pick up (generally hit 5k) and it sounds clean with no smoke is that rite? Also is the screw air or fuel? Im guessing un screw is more flow and tighten reduces? As you can see i have been flying blind having been given conflicting info from people i know
3k is way to high idle... The mixture screw I can't know without seeing the carb, which side of the needle/main jet is the screw? (side nearest reeds or side nearest airbox)
Makes sense Just put 80jet in so is it just a case of all the way in and 1.5 whole turns out with the screw then just tweek till it sounds smoothish?
Yeah that's the ticket. It's wise to blip the throttle between adjustments then wait 20 seconds to see if it creeps down or up.