Yamaha Genesis Exup 400cc - grey import -HELP!

Hey Folks, can anyone help or advise me. I have a Yam 400 Genesis Exup, as picture on the left. Its 1988, an import & seems to be limited - to 80kph, as this is the speed limit in Japan. When I got the bike, it started, had keys and a log book but it hadn t been on the road for a couple of years. Over the few months I ve owned it, I ve learnt a few things - if any one can confirm, that d be great - the restrictor is on the back of the speedo, if i change the speedo i will blow the idu…If I change the speedo an idu for uk spec, will this solve the problem with out a knock on effect?

If any one can advise, throw in idea s or has first hand experience, I d be really grateful for some feedback.

The exup valve was shut but this has now been fixed, Someone else said it could be the dyno…

I look forward to hearing from yas & many thanx for your time ! :smiley:

Well, I am quite surprised that no one has any idea s on this…

Luckily, a nice chap ffrom a bike shop in Staffs, Vyxxn, mailed me this morning with some info on this, apparently not so difficult to solve… we ll see… any thing I touch turns into a circus !

If I get it sorted, You ll all be seeing me on the roads of londinium from 5.30pm to 9 am every night !!!

fingers crossed - - - cummon !