The previous owner of my 2009 XTR removed the snorkel and fitted a stage 1 filter. I bought it in great condition at 2500 miles. Now, at 4500 miles, I'm wondering how it's running, as I'm not sure about these mods without changing the fuelling.

So this morning I took the bike into my local dyno centre for an air/fuel run. My expectation was that it would be a little lean, but nothing to worry about, as that seems to be the consensus on the forum: stage 1 filter and snorkel removal is OK without more fuel.

After an hour, the tech comes back clutching pieces of paper and starts explaining things. His view, in a nutshell, is that at low throttle it's so lean it's almost off the chart. His opinion is that if the bike is used regularly at low throttle or cruising, that it's lean enough to eventually cause problems. On the plus side, power does seem up a couple of bhp on the default XT660 chart. I mentioned a 2000-mile trip coming up and the tech's view was not to use the bike for the trip without sorting the lean mixture.

So I have 4 options.

1) Leave it and hope it doesn't go pop.

2) Buy a standard OEM filter, take the performance hit, and hope for the best. Maybe pay another �35 for a dyno run to see if it's at least better. Keep an eye out for an old snorkel.

3) Buy Kev's fuel and O2 mods. With all respect to Kev, I had hoped to leave the bike as stock as possible without resorting to the DIY wiring that one finds on used vehicles. The stock running of the bike doesn't bother me too much.

4) Cough up the �500+ for a Power Commander. Their usual price is �300 including fitting, plus �150 for the custom map. However, they said the inclusion of the O2 module in the XT kit would probably add cost at all stages, so expect �500-�600. Yikes!

Needless to say, I'm pretty gutted. I certainly didn't want the bike with less performance, and I did expect it to be on the safe side of lean. I'll wait for the quote on the Power Commander option and then see what to do.



Here's the dyno chart.