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The importance of the clutch switch

43K views 73 replies 38 participants last post by  MacBandit 
#1 ·
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
 
#5 ·
Get another lever :p

Interesting bit.
 
#8 · (Edited)
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.
 
#9 ·
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.
 
#10 ·
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.
 
#11 ·
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
 
#12 ·
Any volunteer to check that with a dyno ? :whistle:
 
#17 ·
#18 ·
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.
 
#22 ·
On my 2007 race bike we've got clutch switch disconnected and no key switch, everything run of the kill switch. No problems.:thumbup:
 
#24 ·
Hey mac, does the switch have a modulated type signal or is it simply an on off?
 
#26 ·
Now that makes it much easier. Thanks bro!
 
#28 ·
Sorry to hear bro...
 
#29 ·
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
 
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