Motorcycle Safety & Driveability: Drilled-out tail pipe, pipe, modify

Question
Although I'm not the same Jim as in the previous question, this follows-up the topic of stock versus modified exhaust. Although it's the dead of winter, I just picked up a 2008 V-Star Silverado, which had the tailpipe drilled out for more sound. The added noise doesn't mean much to me, but I an concerned whether or not the engine will suffer in the long-run, and since the bike has such low mileage (2,000 mi.), the dealer has offered to weld the holes when I bring the bike out next month. What are your thoughts about doing this? Am I doing the engine and valves a favor, in the long-run, by repairing the holes?
Thanks, Jim

Answer
Without knowing exactly what was done to the tailpipe (to what degree it was "drilled out") let me offer what I know in the way of advice:

The manufacturer intended the stock engine to run with the stock pipe. If the pipe is modified, you should assume that the engine will be out of tune. By what degree depends on how much the pipe was modified. An out of tune engine will suffer, again, to the degree that the pipe was modified, and churn out a different powerband than stock, run and idle differently, perhaps run hotter or colder, and get different gas mileage. Note that any of these changes may not necessarily be "bad" changes, or even noticable. For example, we may be talking only a half a mile per gallon difference in mileage ... or we could be talking 10 miles per gallon--pro or con.

So the solutions are to weld the holes to bring the pipe back to stock, or to tune the engine to best perform with the freer-breathing pipe. Either way is acceptable.

Welding the pipe would be the simplest and cheapest way to go. Tuning the engine would be a more expensive route, but it might also be a way to make your bike better than it was stock. Or you could do both--repair the pipe AND tune the engine--and get the best of both worlds.

If it were me, I'd have a tuner put the bike on a dynamometer and get it running perfectly ship shape. That is, if you like the sound of the bike now. (If you want it quieter, fix the pipe.) They can custom tune your bike to some degree to get the response and performance you want: maybe you want better low-end torque, or maybe you want more midrange for uphill mountain passes fully loaded with a passenger, or maybe you like running it at redline and riding it like a sport bike. There's lots of variables for the tuners to play with...the only limit really is your imagination!

This reminds me of once, at a rally, a dude with a similar bike (big cruiser) put his bike on the dyno for a few runs. He had done it the year before, gotten a reading of X amount of torque, and wanted to do better. So he put a superexpensive loud custom pipe on it. He brought it back the next year and put it on the dyno again, and he had actually lost about 10% of his power--because he didn't have the engine tuned after modifying the exhaust.

At any rate, best of luck and hope this helps.

Pat