Damage from running performance exhaust without ECM?

[justice27123]

I just bought an 1125r and it backfires and runs a little rough at idle when cold. I figured it had mods done with no ECM. I got a good deal on the bike and took the cover off and I was right. Could this damage the engine at all and which ECM do u guys reccomend. It had a k&n and a jardine rt5

 

[d_adams]

Yes, you will eventually do damage, so either get the EBR ecm that's programmed for it or get it tuned via tunerpro RT.

 

[justice27123]

I don't plan on driving it much before I pick up an ECM but I don't know how long it's been ridden without one. It has 9k on it so I doubt it has many miles on it with the mods and stock ECM.

 

[Big twin]

Yes, you will eventually do damage

I`d like to know what kind of damages ?

 

[d_adams]

Stock is set pretty lean to meet EPA restrictions, adding a free-flow exhaust/intake to it makes it much worse. Eventually you'll start seeing error codes, one is the AFV spread too far apart which means one cylinder is running 25% or more fuel than the other. The stock ecm simply cannot compensate for that drastic of a change in the exhaust system. Once it gets to that point, it's just a matter of how lean is the opposite cylinder, when will it start detonating in the chamber and how long will it last like that before it burns a hole in the top of the piston. Most likely it will run so crappy that you'd notice the loss in performance before you actually do damage, but I've seen it first hand on older bikes. Never seen it on a 1125 yet, but it can certainly happen. It may run on an 1125 for thousands of miles before you'd see or hear anything, but I would recommend getting either a tune or an ecm that's matched to it.

google search for lean detonation hole in piston

https://www.google.com/search?q=lea...S6iwLroYCQBA&ved=0CAoQ_AUoAQ&biw=1280&bih=832

For reference, this is what will eventually happen. It's out of a snowmobile, but it's a good example.