sluggish between 50-60mph

[mk1phase1]

my 1.2 rl prima goes fine up to 50mph but then between 50mph and 60 mph it seems to struggle a bit. once it gets past 60mph it shoots off again. is this normal or is there something i can do to fix it? its a 1994 mk1 phase1 with a 1.2 engine and 4 speed gearbox.

 

[iimushroomzii]

Don't you change gear between 50-60mph? That's why.

 

[mk1phase1]

im usually in 4th between 40 and 50mph. so u think if i wait till between 50 and 60mph to knock it into 4th that will get rid of the sluggishness? it seems like it needs the 5th gear because theres more power there