won't pull past 5000rpm

[30psi]

Originally Posted by datdrift

that is the problem, the idle's sorted, but it cant pull the higher revs on full load without hesitating and spluttering

I was gonna ask this very question.

If it will go past 5,000rpm on light loads then the problem is most likely to be fueling. Either too rich or too lean.

Does it sound like a rev limiter or is it more severe and just a complete loss of power?

[datdrift]

yeah it can pull around past 5k when its not under full throttle.
it was doing a similar thing when i had to run it on some 95ron fuel when it came on boost, but now i only ever run it on optimax.....
it doesent sound too bad when it happens just maybe little poping backfires down the exhaust?
i havent got a timing light so i don't know what its set at, ive tried twisting the dizzy to the left to retard it but it diddent seem to make a difference