Question on Pair Valve temp disable - Motorcycle-Journal Forums

Pavs · 10-13-2008, 02:09 PM

First hello to all as I am a new user for the forum! As you might have guessed I have a problem\question that I require help for.

Here's the situation:
I recently had a Cobra 2into1 HP exhaust system installed along with a Power Commander PC III USB. The local dealer that installed it also mapped the Power Commander with the Cobra 2into1 map which was on the CD (same as down loadable at the Dynojet website). They did not have a Dyno set up to do much further tweaking nor does any dealer near me (Grand Rapids MI) other than a Harley Dealer who of course will not touch my Suzuki.

As you might expect there was still a good deal of backfiring but only on deceleration (engine braking) or oddly enough when you have to tether the throttle a bit in the lower to mid rpms in 3rd or 4th gear to hold a speed (through 30-35 mph speed zones for instance in 3rd gear).

I heard about the PAIR valve modification so as a temp try out I plugged the two rubber lines after at the steel tubes and prior to the Pair Valve.

For the better part this seems to help a lot, but when I first start the bike cold and most notably during the first minute or two during the fast idle cycle I have a good deal of very rich exhaust coming out of the pipe. It is noticeably a bit blackish and you can smell the unburned gas in it. Seems to mostly go away once the idle settles back down and has heated up a bit. (i.e. when you rev up while the exhaust is still cold you still get the same effect).

So my question of course is, is there a way to eliminate this or is it just an unavoidable side effect of disabling the PAIR valve? Would a different mapping help or a map enrichment change (% minus) in the Low and Mid RPM ranges using the Power Commander range settings?

Thanks in advance for any help or advice!