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Discussion Starter · #1 ·
I have a 2003 Speed Four with a micron pipe on it. Can it be tuned without a power commander or is it necessary to have one to tune it? I bought the bike in Tucson and had it tuned by a shop in Phoenix. Now I've moved and local shop is saying I HAVE to have a power commander even though I had it tuned before without one. Any advice or recommendations???
 

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There's two kinds of tunes. One is a straight forward tune-up. The other is mapping the injection to deal with additional air flow from reduced backpressure. The first is likely what the dealer did. For the second, you need a Power Commander or TuneBoy software. I prefer TuneBoy, but it's a personal choice. To remap a bike properly, you need to set aside a fair amount of money and time for dyno work. As a practical matter, if the dealer set the CO, also known as the fuel idle trim, properly, you probably don't need to remap as long as the bike is behaving well and not overheating.
 

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Discussion Starter · #4 ·
tuned...

I had it tuned on a dyno without a power commander and it ran wonderfully for years. Took it to dealer for "tune up" and now it won't idle and dies when I pull in the clutch if the rpms are higher and it comes down. Frustrating! I don't really want to have to buy a power commander. It ran fine without one before. I know I could get better performance with one but not interested in the investment right now and just want to be able to ride my bike again.
 

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I suspect they screwed up the CO setting. With an open pipe, it has to run richer than with the stock pipe, and if the shop who did the work didn't understand what they were doing, it can cause lean surge and other problems at low RPMs. It may also be a problem unrelated to the work the shop did. There may be a vacuum hose off or some other issue such as a new crack in the IAC valve body. It's worth going back to the shop to tell them something they did or didn't do is causing a problem, just to see if they will make it right for you.
 

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If you don't have a PC or TuneBoy, no dyno tech adjusted your ECM characteristics; it isn't possible without one of the two programs. They may have loaded factory maps if they had the proper tool, but nothing custom could have been done. I agree with Will that it is either something the dealership did to the CO setting, or another issue has appeared.
 

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And oh by the way, there is no factory map for a Speed Four with open pipe. For whatever reason, Triumph never developed one.
 
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