Speedo not working properly?

[Smousley1995]

Hi! To cut a long story short I had a Zxr 400 which I utterly wrote off and have now bought another one.
The new one I bought had kph clocks on with an adapter which screws into the speedo and the speedo cable screws into the adapter. I think this was showing the correct speed but I changed it over to the mph clocks from my crashed bike.
Again I think the mph clocks were showing the correct speed but I'm not 100% sure.
Well the mph clocks then stopped working properly and the needle would show the right speed but I would accelerate off the line to 40mph and the needle would sit at 15 for a second and then jump to 40. Any idea what's wrong with that?

So then I decided to change back to the kph clocks. I read about the restrictors in the jap import clocks so I opened up my speedo which meant prising the metal ring around the front off so I could access the internals, I then removed the tab which restricts it and put it back together. The speedo is now reading slower than I'm actually going by around 8mph and becomes less accurate the faster I go?
Now I'm not sure if they were reading wrong when I first bought it because I hadn't rode for a while so I just presumed that I was going 30 when the needle showed 30, however I'm now sure they are reading wrongly which they could have already been wrong or I did something when I opened it up which has caused it? Does anyone have any idea what's wrong with them or how I can fix it?

Also my bike is restricted to 33bhp with washers after the carbs but my last bike did 115mph and could easily use 9000-14000 rpm rev range. When I got the new bike the speedo was showing 80 mph flat out in 6th gear and the engine wouldn't rev past 8000. It didn't hit a limiter or anything it just struggles to find more revs. This is why I changed the clocks and derestricted the kph ones because I thought that could be the reason but that's made no difference. It will rev past 8000 in the lower gears but there's absolutely no powerband and I don't get and benefit or more acceleration from revving it into the powerband. Any ideas as to what may be causing this would be appreciated too?
Thanks!

[harrisonjc87]

Hey,

Not sure on the speedo problem - but when I first got my 400 I had it restricted and top speed I could get out was 90mph and revs were limited... Think thats just pretty standard for how they restrict them with the washers in the carbs.. It'll be like a new bike when you get to take them out and have it full power (:

[Smousley1995]

It seems that 100-110 is about standard for a 33bhp motorbike but I know zxr's are capable of 115 while restricted because I did that on my last one :/ I mainly solved the slow problem in the end anyway, turns out there were two size 88 jets and two size 90 jets in for some reason still not as quick as my last one but it'll do
Thank you for your answer