The importance of the clutch switch

MacBandit · Apr 20, 2011

Well I hadn't posted this sooner as I didn't realize how many people were bypassing their clutch switch. It's important that you don't do this if you want your bike to run properly and smoothly with the maximum amount of power.

I do not take credit for this. This was passed down to my by my Triumph instructor who told me that this came straight from Keihin and that it applies to the new Suzukis as well since they run the same ECU setup.

Obviously item 2 and 3 do not apply to our bikes but most of these do.

The only way around this is to run the race kit ecu and harness.

The Clutch switch is important in the following 13 ways:

1 Decel rate control using the idle speed stepper: Additional steps are used to
soften the decels - when the clutch is pulled in these steps must be dumped
or the bike will hangup or push-on.

2 Fuel gauge - will not update whilst the clutch is in - this is to stop updating
of the sensor when the fuel could be sloshing (i.e. during gear changes).

3 Vehicle speed limiter - This will not work with the clutch switch bypassed.

4 Gear position judgment - The NCT range with no gear position sensor
derives an idea of gear postion from RPM vs Vehicle Speed. This function will
not work so the wrong ignition maps are applied.

5 Gear position judgement other models - The clutch switch will force a
'NO LOAD' condition and use the neutral ignition maps. This overrides the
gear position info and the wrong ignition, second throttle and exhaust
butterfly maps will be used!

6 Ignition smoothing strategy is disabled.

7 Pressure based fuel merging to Throttle based fuel is not merged - its
switched which can cause a jump in fuelling.

8 Deceleration fuel reduction multiplier is not applied - causing rich overuns
- potentially damaging to the CAT.

9 Deceleration fuel cut-off & CAT protection fuel cut is not applied - this will
definitely impact on CAT performance.

10 On some models closed loop will not work when riding.

11 D675 airflap will always be closed

12 D675 exhaust valve will remain partly closed.

13 Starter lock out switch - ie SAFETY

duff_boy · Apr 20, 2011

Yeah i thought as much...

CP_ · Apr 20, 2011

WTF!!??

I was just about to buy an ASV clutch lever and perch which has no allowance for the clutch switch. I wonder if there's any way around this?

baytriple · Apr 20, 2011

I have both clutch and brake ASV levers and everything is the same as standard :nod:

They are lovely levers! :bowdown:

Smoke · Apr 20, 2011

Get another lever

Interesting bit.

Falco · Apr 20, 2011

Too late now, I will have to get it back sometime or get a new ECU.

Logans08Daytona675 · Apr 20, 2011

sorry Don't believe you.... I haven't had mine connect for over 2 months and no issues
Not trying to sound like any kind of know-it-all but my flapper valve is still working and I don't feel any difference in power.

no issues with speed sensor
3 Vehicle speed limiter – This will not work with the clutch switch bypassed.

MacBandit · Apr 21, 2011

As I stated 3 does not apply to our bikes. It does to the Rocket3 which is the only bike Triumph makes with a speed limiter.

That said I am not here to try to convince you or anyone. I am simply here passing this information on which came from Keihin. Also you can verify that the clutch switch does do something if you remove it on a bike that still has the EXUP and intake flapper. I doubt your intake flapper is fully opening when your riding it. It may work however in neutral sitting as the clutch switch is not part of the circuit at this point.

GrimReaper85 · Apr 21, 2011

I also find this very interesting. I've had mine disconnected for four years and haven't had any issues or noticed anything different. There is a slight pause/blip when i go full throttle, but isn't there when i roll on FT.

Flapper valve is kept open through Tuneboy and EXUP removed.

I'll try and put it back to see if the pause/blib goes away.

tooblekain · Apr 21, 2011

I'm with Logan and the GrimReaper...Ive had mine disconnected for over 3 years now and no difference whatsoever. Ive even connected it back when I rode street the few times and still no difference.

This may be true for other triumphs but I dont see it affects us Daytona owners

Smoke · Apr 22, 2011

Any volunteer to check that with a dyno ?

t10vr · Apr 22, 2011

I had it disconnected last year and I didn't notice any difference.Please someone with more experience and knowledge,to give us a better opinion:thumbup:

CP_ · Apr 22, 2011

How could it possibly do all this when it's just a tiny microswitch that is only activated right up against the grip? That is to say, I doubt that the clutch switch is even activated on 95% of my gear changes.....

googlevfr · Apr 22, 2011

i think

im prety sure its only the 09+ cos i took mine off and it made a massive difference but 08 dont seem to have a problem

tooblekain · Apr 22, 2011

googlevfr said:
im prety sure its only the 09+ cos i took mine off and it made a massive difference but 08 dont seem to have a problem

That's what I think too...but mine is a 2006

G.I.Bro said:
didn't the ECU's change between 06-08 and the 09+ bikes?

I believe they did

G.I.Bro · Apr 22, 2011

didn't the ECU's change between 06-08 and the 09+ bikes?

Palm Bomb · Apr 22, 2011

I know for a fact this isn't true with my 06. I had it on a dyno 3 weeks ago. Tuneboy map has all valves/etc open. made max power without issues and runs like a fucking champ.

MacBandit · May 2, 2011

What about on/off throttle smoothing?

Logans08Daytona675 · May 2, 2011

This is good to know that I am not the only one out their thinking this....

xd675x · May 9, 2011

On my 2007 race bike we've got clutch switch disconnected and no key switch, everything run of the kill switch. No problems.:thumbup:

MacBandit · May 9, 2011

We reinstalled the clutch switch on one of our bikes and it seems to have smoother throttle control.

Tonymac · May 9, 2011

Hey mac, does the switch have a modulated type signal or is it simply an on off?

MacBandit · May 9, 2011

On/Off.

Tonymac · May 10, 2011

Now that makes it much easier. Thanks bro!

GrimReaper85 · May 11, 2011

Thinking very hard back when i did the mod, i beleive i noticed my problem here
Slow Throttle Response, popping/lag under WOT! NOT FIXED!! - Triumph675.Net Forums

As soon as the bike gets all back on track, i'm going to put the switch back on. I'm betting this is going to solve my problem.

Edit: I was never able to fix the problem.

Tonymac · May 11, 2011

Sorry to hear bro...

deuce · May 26, 2011

I find this interesting, but confusing (my bad

Unless you have intentionally bridged the circuit, and the bike is starting, how could the clutch sensor be not working?

Can it work badly or not as designed with aftermarket levers? Is there a clutch sensor elsewhere you can rely on?
I mean you know, can feel when your clutch is working or not..cant you

MacBandit · May 27, 2011

A lot of people disable/remove them for track use and so they can start the bike without pulling in the clutch.

PCFRonin · May 29, 2011

That and to remove the useless controls Hi/Lo Beam, Pass and indicator buttons.
Which is what I've done on my 08' (non painted engine version)
AFAIK its the same experience.... Worst case I'll run the 2 wires to the switch in the clutch mount

Pickled Onion · May 29, 2011

The switch gear next to the clutch, can this be disconnected from the loom without any mods?

The importance of the clutch switch

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