jap restricted v max

hi i got a jap v max , bought vboost manifolds, carbs, servo etc . V boost opens at 6000 but there is some sort of rev limiter kickin in . also need to change stock 190 kph sppeedo for 260 one different connections reed switch ect.
Has anyone out there modified a jap spec max and if so what has to be done

Jap restricted Vmax . Must be a non vboost model or has it a speed limiter on it . I imported my Max from Japan but its Canadian stamped . Had mine 220kmph+ . Mt agent told me that they didnt have speed limiters on them .
The imported cars in the 80s had them tho but you could bypass this somehow .

hi i have a jap restricted v max and you also need a new ign box i got a dyna 3000 box.
or you can open the speedo and bypass the speed restricten but it is a pain in the ass.

There's a little disc behind the face of the speedometer that trips the speed limiter. There's a tutorial somewhere(think it might be on vmaxoutlaw.com) on how to bypass it----not that big of a deal to unlock the Vmax's true potential.

Mine was a Jap import! Here's what I replaced...

Exhaust, Carb jets, VBoost system, Speedo restriction, Carb diaphrams, CDI

Here's a writeup of the first of the process, I used a manual VBoost until I sourced a servo, '97 CDI, conrods (these were just to fix a knocking problem I had)
http://johnpclynch.gotdns.com/Jooml...le&id=5:vmax-restricted&catid=1:vmax&Itemid=7

Also check that your cams are correctly aligned... My rear exhaust was out a few degrees from spec!
http://johnpclynch.gotdns.com/Jooml...icle&id=8:vmax-teardown&catid=1:vmax&Itemid=7

john, u have some great info there bud!

gunrunner said:

Jap restricted Vmax . Must be a non vboost model or has it a speed limiter on it . I imported my Max from Japan but its Canadian stamped . Had mine 220kmph+ . Mt agent told me that they didnt have speed limiters on them .
The imported cars in the 80s had them tho but you could bypass this somehow .

Click to expand...

Speed restriction on the japanese model #01
by Morten, Jun. '98
I'm a danish Max'er with a 1990 Jap-home-model. It's been fitted with the original Yamaha V-boost (of course!), 'cause without the boost it's not "The Real Thang", right? I have a problem though....

My Max is still limited at top speed 190 km/h. Do you know how to get rid of that limitation? I've tried to open the speedometer, but it's one whole encapsulated plastic "house"....so that you can't tamper with the milage I guess. Some say, that the top-speed limitation is in the speedo, and other says, that I need to get an ignition-advancer to get the full potential of the bike. I don't know where to turn! There's no limitation at all at the revs - it boosts from 6.000 rpm to the redzone like it's supposed to. But you know in 5th. gear your "flying" with app. 180 when it turns open, but at 190 (homemarket models have this sorry speedo..) it turns off until the needle hits the mark 190 again and you fly on... Hmmm !

Can you help me? I hope so. Ya' see, not many know much about our beloved Mr. Max here in Denmark. Hope to hear from you or others !

Multi-Max Greetings
Morten "MadMan" Valbj?rn


The Solution

Earlier I tried this HELP-site to find out how to get rid of the Speed-restriction on the 1990 Jap-homemarket model....

The answer came from VMax-club Norway...
One is to buy a "Speed-Restriction Modification". It is to be mounted in the headlight. It's a small box which goes between to wires to cheat the electrical system. I haven't got hold of one yet,so I can't tell you much more about it, yet. You should be able to fit it in app. 5 minutes with the use of a screwdriver - niiiice!

Where to get it?
Speed & Dyno Shop, Oslo Tel. (00)47 6706 0882 (9:00am-12:00am)
Cost: 2614,- Nkr.

See ya' Morten "MadMan" Valbj?rn

so far have changed to vboost unit, carbs ,servo etc CDI,
trying to sus speedo next . ive got a 260kph speedo to fit on instead of the 190, but wiring / connectors are different anyone done this already?