Help with motorcycle tune please

Thread Starter

Tifa

Joined Nov 5, 2009
17
Happy New Year Everybody!

I have a Honda 1000cc motorcycle that I intend to use for track use.
To enable an accurate and worthwhile tune it's necessary to remove the emissions EVAP unit.
Ordinarily I'd simply replace the harness with a race item, however cost is a factor.
My thinking is, to remove the EVAP system and control valve, but this is connected to the bikes ECU vis CANBUS.
If I delete the valve, it's likely to throw up error codes....??
So....looking at the bikes manual, it appears that when unconnected the resistance across the 2 terminals on the evap valve should be between 23 and 27 ohms. (These are the values given for test purposes)
I am considering removing the valve and using a 25 ohm resistor to 'fool' the ECU into thinking the valve is still connected?
Is there anyone that has an opinion on this please?
Likely to create more problems?
Thanks!
 

MrSalts

Joined Apr 2, 2020
1,506
It should be ok unless...
if the bike has a way of sensing whether the valve actually opened (or closed) when power was applied, then you may have a problem.
 

Thread Starter

Tifa

Joined Nov 5, 2009
17
Thanks MrSalts.
Very much appreciated.
I'm thinking the valve doesn't send any signal to the ECU, but the resistor uses as much energy as the solenoid inside the valve would by dumping it as heat. The ECU thinks the signal was used by the valve because the returned voltage drop is correct?
 
Last edited:

MrSalts

Joined Apr 2, 2020
1,506
Thanks MrSalts.
Very much appreciated.
The ECU thinks the signal was used by the valve because the returned voltage drop is correct?
That is likely and worth trying. Especially likely if an error is thrown if the value is removed. However, it is possible that an error is thrown when the ECU activates the valve and the emission system doesn't detect a change anywhere else downstream. In other words, the bike may not be looking for the valve, but it might be looking for a chemical/electrical/mechanical result of switching the valve.
 

Thread Starter

Tifa

Joined Nov 5, 2009
17
Good thought!
I'm thinking that when I delete the valve, I'll re-route the fuel tank vent below the bike (the old fashioned way!)
And blank off hose connections to the manifold and airbox.
That way, I don't think the air pressure sensor will throw a fit.
 
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