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fracture
07-17-2007, 07:09 AM
I have been looking at getting a used oilhead. In reading the descriptions of bikes for sale I notice some bikes have had the exhaust changed. Sometimes only the muffler, sometimes the entire system.

I looked at one bike in my area. It is an R1100RT. Among the rather extensive mods is a complete exhaust change. I did not see a converter, just smooth pipes all the way to the muffler, which I could not identify. Also, no oxygen sensor. At least, I could not see one. The owner of the establishment selling the bike said he rode the bike and claimed it pulled harder than a stock bike. Maybe so. I did not ride it and even if I did, I would have no way to compare it to what it was like in stock form.

Without the oxygen sensor is the control unit in an open loop or is there some electrical modification to fool the system into thinking that the sensor is still there?

I have nothing against making mods. There may be considerable weight savings to an aftermarket system but since the weight is carried very low this may not be noticed. And, I am wary of some claims. Many aftermarket systems may make more noise than additional power.

There are pros and cons to this. The pros include getting rid of some weight (maybe not that big of an advantage), getting rid of the converter which from what I hear gets very hot and cooks the underside of the bike, and possibly a performance gain.

The cons: Although this may not occur for a few more years, what if inspection laws change in my state and motorcycles have to go thru emissions testing? I see this as a distinct possibility. There is talk in some states of doing this to lawn mowers, so how can motorcycles continue to be exempt? If the stock system has been discarded, what will it cost to put it back to the way it was? Much would depend on the wording of the law and "older" bikes may be grandfathered. Then again, the bike may have to contain whatever components it had when originally sold in order to be legally ridden.

For those of you who have changed exhaust I would like to hear what you have to say about your experience. And, if you now live in a state with motorcycle emissions testing, is the test the same for a bike as it is for a car?

podsobinski
07-17-2007, 08:00 AM
Being an old enduro racer, one of the first modifications I always put on my dirt bikes was an exhaust first then a header second. This would always: 1. save weight 2. sound better 3. improve performance (in that order). After riding BMW's for 20 years now and several header and exhaust modifications that order is still true but the cost has increased considerably. Without the balance box/catalitic converter you do add the ability to use leaded gas that might be the only gas available outside the U.S. I am presently running a Remus header and Super Trap exhaust with no preformance gained but sounds deep and a lot of weight lost. Any premium exhaust and header should have the oxygen sensor or paper work about elliminating it. My R1200RT is stock but I am thinking about a StainTune just because the stock is too quiet and looks of the StainTune is beautiful and adds a personal appearance from all other R1200RT's. I would be a little skeptical about an unknown brand on that bike. Most BMW owners keep the stock parts for resale and all the info for aftermarket parts. Get the last owners name and find out about the exhaust and header. If the dealer will not give you that info. stay clear something isn't right.:dunno

GPodzo

Most motorcycle problems are caused by the nut that connects the handlebars to the saddle.