CB-1 restriction to 33bhp

[Vermilion]

At first I want to say "hello" to all of you. I'm from Poland (and so my English isn't perfect) and I already bought a 1992 CB-1 in perfect condition. I just have a little problem (or not) with it.

So the bike few years ago was riding in UK, as the half-license bike and so it has 25kW Power in documents. Actually this restriction is a rpm limiter. When bike reach 11500rpm it can't go further and makes "dydydydydy". Is it a fabric restriction? Where could it be placed. Is it possible that it is just a Blackbox that limites rpm or maybe a ignition module or maybe an exhaust kind restriction?

[mrbones]

Restricting RPM would be done electronically. A look at a dyno chart would tell if it would actually limit it to 33hp. Other ways to restrict engine output would be to make the intake hole smaller and cork the exhaust. That's about all I know since we don't have half-licenses here in the US, but when I see a new rider on a 1100cc sportbike, I think we should.

[91cb-1]

I had a restrictor on the inlet ports that restricted at 11500 in 6th gear, simply because you couldn't get enough fuel to the carbs to get the revs higher, try running it past 11500 in 2nd or third if not i'm not sure how it's restricted. oh and Welcome to the site, hope i have helped

[Vermilion]

It stops on 11500 at every gear so I don't think it could be mechanical restriction. I bet an electronic one. But where should it be? Should I look somewhere under the tank for a blackbox ? Maybe there were an restricted ignition modules originaly made by Honda like in Honda NSR 125? Oh and i forgot to add that my cb-1 is US version with speedo in miles.

[91cb-1]

Ah ok so max about 90-100 miles with restrictor 110-120 without, haven't a clue where to tell you to look for your restrictor, sorry

[Davie Thistle]

.....STILL,
it would be interesting to see & know how it's done.

I would like it done to my machine,
the nephew & son wants to learn to ride!

would be very handy!!!!!

[PeaceKeeper]

As standard US versions of the CB-1 have no such restrictions in place, I would look for a part that is non-standard.  You can probably start by matching numbers on the Computer Module to what would typically be found in that model/year.  If that matches, just start looking for anything else that seems out of place.  They must have added something when it was imported to the UK to make it adhere to the restrictions.

Hope that helps.

[Vermilion]

I de-restricted it easily. That was additional module called "BlackBox BB" It was pluged by wires to the ignition module and it cut ignition at 11,5rpm. Removing it was very easy, just managing few wires and it works on full now .

[91cb-1]

Great to hear you got her on full power, she's even more fun!