Slow top speed

[acmetalhead]

my ZXRs top speed is only 120 and i thought the top speed of the 400s was at east 140. i read that some are restricted to 110 by the speedo but since mine does 120 i don't think that is the problem . Any one got any ideas why it is so much slower?

[zimm]

some have smaller carbs,..

I had one that wouldnt top 120 due to fuel starvation issues .. finally traced to badly setup (and smaller) carbs

maybe it's just a bit tired ? low on compression ? tight topend ? badly setup ? do you tuck right in ? how does it run otherwise ? is it standard ? or modded ?

should be good for 135mph stock if no problems, maybe more.

[acmetalhead]

yeah tucked in as much as i can. its standard apart from a Remus end can and seems to run great apart from the slow top speed. its my first biggish bike so i got nothing to compare it to tho.

[masterofinsanity]

has anyone changed the sprockets for aftermarket ones? maybe a bigger rear for wheelyin but you will loose top end speed.

[zimm]

get it dyno'ed i'll put some imaginary money on it running lean and needing re-jetting, and maybe even having the smaller carbs.