[keeksrc51]

Recently bought a new old stock 2005 RC51 - absolutley love it.
Have read on rc51.org (ROUGUE RC 51) about the flapper & soft rev limter mods, however, all the info refers to the 2000-2003 model years.
Does anyone know if these changes benifit the 05 model the same way?

[robfromsc]

02 on is the same

[whylee]

Yes, you will get the same benefits with these and other mods mentioned on here and on other sites.

[ChrisR1982Edin]

Honda stopped development on the bike after the 02 model. All RC51s/SP2s are the same from 02 onwards, all they changed is the paint scheme

Any of the mods there will help you out

ROGUE is a good source for info

[i<3my00rc51]

Can anoone link me to flapper and soft rev limiter mods pls I don't know if the last owner have done this already thanks alot

[ChrisR1982Edin]

ROGUE RC51 Flapper Valve Mod Page

This modification removes the soft rev limiter that was intentionally placed on the motor by the designers of the motor.

there ya go

Curious... what does the Soft Rev mod do exactly?

[rc30sp1]

hi there im new to this forum so hear goes,does anyone know if the free mods work/are ok/relevent on a 01 uk bike. cheers

[i<3my00rc51]

How come they won't show the soft rev mods till u pay the dues on rc51.org

[ChrisR1982Edin]

Originally Posted by i<3my00rc51

How come they won't show the soft rev mods till u pay the dues on rc51.org

They do show you....

RC51 B2-A15 soft rev limiter mod

Explains it there

Remove your tail section & undo the T shaped cover attached (4 push pins) on the bottom of the tail section right behind the battery. Under that there will be a black ECU box with a gray connector & a black connector.
This mod is best done with the PCII, as you can do the mod by splicing into the PCII harness instead of the ECU harness & if you ever need to undo the mod you can make it look 100% stock
You can obtain your own connectors from a cd-audio cable (pictured below) as it has the perfect size connectors to match the ECU pins.

[zerogara]

I have seen many threads on this and didn't find the answer and then I have one more question.
> Curious... what does the Soft Rev mod do exactly?

Everyone talks about it, people do it, but nobody really explains what it does, although I've seen stock and modified dyno charts to see that power falls off gradually without this modification to the rev limiter in the last 1000rpm.
Does it retard ignition at the top? In certain gears only or all of them?

The other question I have!
I assume the flapper valve exists in all US/N.American bikes and the rest of the world, but what about PAIR and soft rev. are they all the same or do they match emission restrictions of different parts of the world?
I understand the PAIR is an emissions assistant to burn unburned fuel and/or CO to increase CO2.
Then there were California edition bikes that were even more restricted; How?

[zerogara]

Well, Subsailor gave an answer in an other thread so I am adding it here to clear the puzzle.

Originally Posted by SubSailor

US and Canada (North American) models had a "soft" rev limiter that retarded the ignition advance at 9200 RPM and decreasing power.

The rest of the world did not have this and their engines revved up to the "hard" rev limit of 10.2K RPM where the ECU cut spark to the cylinders.

The soft rev mod removes the soft rev limit and allows the engine to rev to it's full RPM capability like the Euro bikes.

Since HP is a calculation of torque and RPM, just allowing the engine to rev another 1000 RPM can add around 5 HP or more depending on other engine mods, state of tune, etc.

[rc30sp1]

many thanks for info.