hi my bike came with a dyno printout of 31 bhp and the kid i bought it off said it was restricted because he past his test at 18.my mate said it does feel a bit sluggish we have taken the carbs off and no restricter in the inlet nothing in the carbs to restrict it and on the paddock stand (haven't got my full licence yet so cant take it out) revs freely to 14000 rpm well past 110mph on the speedo so its not the cdi where else do i look or would it be best to just get it on the dyno again to see what power its making now

The only way of restricting the ZZR is with carb washers. If the clocks are still reading kph, then it is most probably still governed to the 114kph restriction. A healer (mph converter) will fix that. If there's no washers in between the carbs and the engine (in the rubbers) then 31BHP is all you're likely to get, I doubt anyone would have restricted the slides or the throttle, they are not the ideal way and do not guarantee output.

Depending on the model year, the factory fresh BHP could be anything from 48 to 62. Bear in mind that some of the horses will escape over time and a badly set up bike will also reduce horses.

thunderace wrote:The only way of restricting the ZZR is with carb washers. If the clocks are still reading kph, then it is most probably still governed to the 114kph restriction. A healer (mph converter) will fix that. If there's no washers in between the carbs and the engine (in the rubbers) then 31BHP is all you're likely to get, I doubt anyone would have restricted the slides or the throttle, they are not the ideal way and do not guarantee output.

Depending on the model year, the factory fresh BHP could be anything from 48 to 62. Bear in mind that some of the horses will escape over time and a badly set up bike will also reduce horses.

hi thanks for the quick reply the bike is a 1988 zx 400 and forgot to mention i have the before and after dyno one reads 54.16 before the restrictor and one reads 31.11.the kid said its still restricted but i cant find the restrictors anywhere so if there not in the intake do you think he has taken them out?

I'd say they've been removed and you have a badly set up bike.

thunderace wrote:I'd say they've been removed and you have a badly set up bike.

ok thanks haven't taken it out since we cleaned and balanced the carbs il get someone to take it for a blast tomorrow see if its any beter

are the slides lifting all the way or are there plastic spacers in the carb tops ?