[icymike]

I recently bought a 2005 s2r. It's completely stock except for termi exhausts. I was told that the exhaust w/o a tuned ecu can cause the bike to run lean.

In my experience it seems bikes that run lean don't backfire, but rather too rich of a mixture will cause backfiring.

Could my valves be out of adjustment? Do I need to get a power commander or DP ecu? I've heard the fuel injection on these bikes can be "tuned" by changing the injector pulse timing (mathesis tune?). Would this help?

Thanks!

 

[MDO]

I recently bought a 2005 s2r. It's completely stock except for termi exhausts. I was told that the exhaust w/o a tuned ecu can cause the bike to run lean.

In my experience it seems bikes that run lean don't backfire, but rather too rich of a mixture will cause backfiring.

Could my valves be out of adjustment? Do I need to get a power commander or DP ecu? I've heard the fuel injection on these bikes can be "tuned" by changing the injector pulse timing (mathesis tune?). Would this help?

Thanks!

It's pretty common for these bikes to pop on decel once an aftermarket exhaust system is installed. They're programmed pretty lean from the factory for Euro 3 emissions and very reactive to any change in the air/fuel mixture or exhaust backpressure. I have Arrow slip ons on my S2R and it pops occasionally, but much less than when I had a straight collector pipe (no udder) installed. My dealer wanted to sell me a PC III for $300 plus another $300 to program it but was uncertain if it would fix the popping. I wasn't willing to spend $600 + and not get a fix so I took a pass and re-installed the udder. It runs fine now and pops only intermittently. Others here may know first hand if the PC III will fix the popping but I couldn't confirm when I investigated two years ago.

The DP ECU might be the solution but they're not cheap either. Others on this forum should have more info on cost and effectiveness. (I think your red key won't work with a DP ECU?)

If you have just slip ons and it's not real bad, you might want to live with it. If you have the straight collector pipe, you're probably going to have spend some money to mess with the fueling to get it to run right.

Good luck.

 

[plan-b]

I had an SV650 that did this when I installed a slip-on. On that bike there was a valve that injected air into the exhaust flow to burn up unspent fuel. I don't remember exactly what I used but plugging up this valve (I think it's called a PAIR valve) made the popping go away completely. If I remember correctly, it was a $3-4 mod. I'm not sure if Ducati has this system on the Monsters. My 08 S2R pops like mad w/ the stock mufflers. I can't even imagine what will happen when I go aftermarket.