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General Category => Tech Corner => Topic started by: mikeNic on November 05, 2017, 03:39:09 PM



Title: CB-1 restricted
Post by: mikeNic on November 05, 2017, 03:39:09 PM
Hi All
I said I would be back, I have just been going through the paper work from new acquisition and came across a form that indicates that the CB-1 I bought has been restricted to a performance limited to a max of 25kw.

I notice that an unrestricted model has some 41.2kw.

Can anyone tell me what form this restriction would take as I would wish to remove it and return it to standard.

It may be however that it has been removed as the certificate is dated 1999' but without knowing what was done I do not know.

regards

Mikenic


Title: Re: CB-1 restricted
Post by: a_morti on November 05, 2017, 05:32:02 PM
Hi mike!
The restriction is very simple. Remove he carbs, and if it is still restricted there will be a metal washer in each intake port to reduce how much mix can enter the cylinder. Remove that and you're done.


Title: Re: CB-1 restricted
Post by: mikeNic on November 06, 2017, 01:08:15 AM
A_morti
Many thanks for that info! I am just waiting on a carb gasket set then I will be removing the carbs and so be able to check that out, probably when I get back from the Canary Isles.

I will let you know the outcome, if it was that easy they have probably been removed

Regards
Mikenic


Title: Re: CB-1 restricted
Post by: Dash on November 06, 2017, 03:10:15 AM
Sometimes bikes get restricted by limiting the amount of throttle you can give by mechanically 'blocking' the throttlehandle from twisting any further. It's quick and easy to check. Usually there s a small bolt in the throttlehandle somewhere that functions like a stopper when a bike is restricted in this fashion.


Title: Re: CB-1 restricted
Post by: mikeNic on November 06, 2017, 03:23:25 PM
Thanks Dash

I will check that out when it warms up in the garage! just what was the purpose of restricting the bike was it a licence thing?

mikenic


Title: Re: CB-1 restricted
Post by: Dash on November 07, 2017, 03:04:28 AM
Thanks Dash

I will check that out when it warms up in the garage! just what was the purpose of restricting the bike was it a licence thing?

mikenic


Well, since you mentioned 25kw...

Does it happen to be / have been a Dutch registered bike? In the Netherlands we used to have a restricted motorcycle license that allowed only 25KW output on bikes. So Maybe that's where it's from?


Title: Re: CB-1 restricted
Post by: mikeNic on November 09, 2017, 10:43:53 AM
Hi Dash

No! the relevant paperwork / certificate of restriction was done by a firm in Daventry and tested by a firm in Bexhill on Sea and must be a proper test job as all power outs are recorded on the certificate and is reduced to a Max speed of 98mph 156kph if it goes that fast I will probably c--p myself.

But I will still have a look for the nature of said restriction

regards

Mikenic
PS further reading of the certificate lists

Restriction  Device
a    Blade
b    Device code  02-NC27-K25
c    Device Details and Dim's
Outer Dia =   35mm
Inner Dia   1= 17.5mm
Inner Dia   2= 3mm
 All alien to me   
                                                         
                                                                                           


Title: Re: CB-1 restricted
Post by: Dash on November 09, 2017, 10:49:33 AM
Hi Dash

No! the relevant paperwork / certificate of restriction was done by a firm in Daventry and tested by a firm in Bexhill on Sea and must be a proper test job as all power outs are recorded on the certificate and is reduced to a Max speed of 98mph 156kph if it goes that fast I will probably c--p myself.

But I will still have a look for the nature of said restriction

regards

Mikenic
PS further reading of the certificate lists

Restriction  Device
a    Blade
b    Device code  02-NC27-K25
c    Device Details and Dim's
Outer Dia =   35mm
Inner Dia   1= 17.5mm
Inner Dia   2= 3mm
 All alien to me   
                                                         
                                                                                           


Then the whole 25kw thing is a coincidence I guess.

The bit about the restriction device speaks of diameters... That would suggest a restriction in the carbareteurs like Morti said. At least, I reckon it does. :P


Title: Re: CB-1 restricted
Post by: a_morti on November 09, 2017, 01:48:07 PM
It's exactly that, a washer fitted between the engine and the carbs. 35mm outer, 17.5 inner and a 3mm additional hole to allow a little extra through.

The cb-1 runs surprisingly well restricted in this way, you probably won't notice it until you remove it and even then it's mostly just a bit of extra top end which you won't notice most days normal riding.


Title: Re: CB-1 restricted
Post by: mikeNic on November 09, 2017, 02:38:20 PM
Thanks Guy's
Your answers have removed the mystery around Restrictors, now I know what to look for I will have look when I remove the carbs to fit new seals
This will now have wait as I fly to the Sun on Saturday
Again
Many thanks

Mikenic