Bike wont rev over 5k, help!!

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Tom1
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Joined: Tue Aug 03, 2010 6:27 pm
Bike owned: 1990 VFR400 NC30
Location: Sheffield
Re: Bike wont rev over 5k, help!!

Post by Tom1 »

Thanks for the quick reply.

And that will de-restrict the bike?
Neosophist
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Re: Bike wont rev over 5k, help!!

Post by Neosophist »

Well it'll let it rev over 5500rpm.

JDM bikes were limited to 180km/h.

Once it's running again, if you find it stops dead at around 180km/h then it's still restricted.

A common way of desrestricting them is to open the speedo (it's only screwed together, not sealed so comes apart easy)

You'll see a metal disc that contacts sensors when the needle hits 180km/h. If you manually turn the needle to around 180km/h you'll soon know the disc as it moves inbetween two sensors. It's probably around 3cm long.

This metal disc is only tacked on with two rivits and a small flat bladed screwdriver will pop it off, and no more restriction. You must still leave the speedo-board connected so the bike thinks the speedo sensor is still inplace but with no disc to trigger it then device will never kick in.

You can also buy plug-in boxes and other gear but this is the easiest / chepeast way to do it and it's undetectable unless you take the speedo apart again.
xivlia wrote:i dont go fast on this bike so really do not need a rear brake.. /
vic-vtrvfr wrote:Ask xivlia for help, he's tackled just about every problem u could think of...
Tom1
Settled in member
Posts: 45
Joined: Tue Aug 03, 2010 6:27 pm
Bike owned: 1990 VFR400 NC30
Location: Sheffield
Re: Bike wont rev over 5k, help!!

Post by Tom1 »

Right so even though i have a koso speedo, i still need to connect the the speedo board to the bike, but it wont be restricted to 180km/h..

Sorry ive never understood it.

Thanks again
Neosophist
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Re: Bike wont rev over 5k, help!!

Post by Neosophist »

Tom1 wrote:Right so even though i have a koso speedo, i still need to connect the the speedo board to the bike, but it wont be restricted to 180km/h..

Sorry ive never understood it.

Thanks again
Thats your problem then!

You don't have the speedo board connected.

If your not using the original speedo you can use a resistor in place of the large (in comparission) speedo board.

Find the plug thats by your clocks that originally plugged into the speedo clocks.

Get a 2.2k ohm resistor.. about 6p from maplins.

Here's a high-res pic on how to do it. but all you do is connect the resistor to the two outer wires in that plug.. brown/black and orange blue I believe.. You can cut the plug off and solder it straight to the wires if you want, just make sure to use some heat-shrink tube to fully insulate it.

http://www.400greybike.com/files/NC30%2 ... 20how2.jpg
xivlia wrote:i dont go fast on this bike so really do not need a rear brake.. /
vic-vtrvfr wrote:Ask xivlia for help, he's tackled just about every problem u could think of...
Tom1
Settled in member
Posts: 45
Joined: Tue Aug 03, 2010 6:27 pm
Bike owned: 1990 VFR400 NC30
Location: Sheffield
Re: Bike wont rev over 5k, help!!

Post by Tom1 »

Thats fantastic! Thanks a lot, ill let you lads know how i get on!
magg
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Bike owned: VFR400
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Re: Bike wont rev over 5k, help!!

Post by magg »

There is a resistor bypass mod that can substitute for the speedo sensor if you prefer.
Neosophist
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Re: Bike wont rev over 5k, help!!

Post by Neosophist »

magg wrote:There is a resistor bypass mod that can substitute for the speedo sensor if you prefer.
Find the plug thats by your clocks that originally plugged into the speedo clocks.

Get a 2.2k ohm resistor.. about 6p from maplins.

Here's a high-res pic on how to do it. but all you do is connect the resistor to the two outer wires in that plug.. brown/black and orange blue I believe.. You can cut the plug off and solder it straight to the wires if you want, just make sure to use some heat-shrink tube to fully insulate it.

http://www.400greybike.com/files/NC30%2 ... 20how2.jpg
Read my original post, it's already covered.
xivlia wrote:i dont go fast on this bike so really do not need a rear brake.. /
vic-vtrvfr wrote:Ask xivlia for help, he's tackled just about every problem u could think of...
magg
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Posts: 1918
Joined: Mon Sep 20, 2010 11:55 pm
Bike owned: VFR400
Location: Blue Mountain NSW Australia
Re: Bike wont rev over 5k, help!!

Post by magg »

My apologies I missed the second page of the post.
Tom1
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Posts: 45
Joined: Tue Aug 03, 2010 6:27 pm
Bike owned: 1990 VFR400 NC30
Location: Sheffield
Re: Bike wont rev over 5k, help!!

Post by Tom1 »

So with this high res pic, all i need to do it the Speedo plug end. I dont need to do the resistor mod at cdi end do i?
magg
Senior Member
Posts: 1918
Joined: Mon Sep 20, 2010 11:55 pm
Bike owned: VFR400
Location: Blue Mountain NSW Australia
Re: Bike wont rev over 5k, help!!

Post by magg »

Yes, you put the resistor at one end or the other but not both.

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