110MPH Restriction

[Jaicen]

Anybody have a definitive answer as to how to remove the speed restriction on a GK76a?
Mine is an SP, which has a single plug CDI, and i'd like to derestrict it. I have searched the forum, but I can't find anything about how the restrictor actually works.
My concern about tricking the bike into thinking it's running in 3rd gear all the time is due to the retard/advance function built into the stock CDI, which keeps the engine from detonating at high revs, and keeps things smooth at low revs. Obviously I don't want to lose that.
Can anybody shed any light on this topic?

[greywolfhunter]

i know little but here we go, I know lower in the sump of the gk73a there is a small circuit that can be manipulated into thinking its in 3rd gear all the time, however you will almost certainly lose lower end power aswell as potentially over-fueling and at lower revs, causing engine cooling aswell as increasing the revs and (over a prolonged time) causing excessive fuel to drip into cylinders and causing excess wear on the piston rings and cylinder. i wouldnt reccomend any big / super tech modifications for these bikes, they're made perfect already, and if you want more power, get a bigger bike. baby gixxers weren't meant to out-do they're 600 counterparts.

in short, get a bigger bike, or destroy your 76a... your choice.

[lloydspencer]

But wasn't the 110mph restriction purely to satisfy the Japanese speed restriction.

The bikes were designed to rev freely and reach up to 125mph. Then a restriction was put on them.

I am sure there must be a way to derestrict it without causing long term problems.

[Andy]

A M-Max box is the answer if you can find one or you can use a small resister to sort the problem out but ultimately(in my opinion) it`s the box mate,hope this help`s.....

Regard`s
Andy

[lloydspencer]

Can you get them new anywhere?

OR do you have to wait for them to pop up on ebay, yahoo japan etc?

[Variablevalves suck]

Its well documented and an easy fix. The gears sensor thats just below the front sprocket has two wires, one is neutral and the other sends a different resistance or each gear. As the cdi see's the resistance it gives full advance or cuts the ignition to stop the bike going over 180KPH. The M max boxes work the same as the DIY, they just have a pritty box. You disconnect the gear wire and put a resistor ther that only reads one resistance, so long as the resistance is lower than the 4th gear reading ( or higher carnt remember) the cdi will give full revs. The standard fix the Japanese did back in the day was 1.5K ohm as this was said to give the bast setting.
I run this but have never dynoed with different resistances to see if these any diference, but these bike are elctrically pritty simple so dont go thinking they had multipul advance curves etc.
If you put a ohm meter on the wire and change thro the gears you can test each resistance given and try any one of them.

[lloydspencer]

http://cgi.ebay.com/ebaymotors/Speed-De ... ccessories

Would something like this be any benefit as well as getting rid of the speed restriction?

Or should I stay away from things like this?

[Variablevalves suck]

Dont spend money on a chinese box they have had a lot of bad press. The resistors are so cheap i had to buy about 20, if you need one PM me and i will sort you one out.

[lloydspencer]

I don't need it yet but I may do in the very near future.

You have said on previous posts that you sell the carb oring kits.

Do you sell any other bits for GSXR's?

Do you do it commercially or just to help fellow riders out?

[Variablevalves suck]

I just supply the o'ring kit. I buy in bulk and then just supply at cost so these bikes can stay on the road.
I got sick of people asking why the bike ran crap and then within the month it would be on ebay in bits.
If you buy the o'rings from Suzi they cost over £80 so at £11 a set its got to be worth giving them a go before throwing the towel in.