2001 M900ie Running lean

[Gimpy]

I have been doing a little winter maintenance on my bike, (2001 M900ie) so I swapped out plugs and noticed they were quite white.  The bike has always chugged a bit under 3k RPMs but other than I haven't had any problems with back firing or any other symptoms.  All this leads me to the conclusion the bike is running a little lean, but only just a little.

I would like to remedy that, but I don't think I want to go the whole DP ECU, PCIII, or major dyno tuning routes.  I don't really want to increase performance. I just want it to run smother.   

Is there such a thing as a fuel mixture screw on a fuel injected bike? Is there any other adjustments I can make? Can I take this to a dealer and just have them tweak it a bit? How much success can I expect from these low level fixes? 

Thanks in advance.

[2001cromo]

A dealer or someone with a Mathisis/DDS can adjust the idle mixture, but this only changes the idle mixture not any where else in the range. That's the only thing that can be changed stock.


<--This all ASSumes that the rest of the tune is pefect.

[scott_araujo]

Stock intake?  If you've got a K&N air filter, pods, or cut the top of your air box open you need more that this.  If you're running the stock intake there is hope.

As already mentioned, the only adjustment you really have is an electronic one that can be done via Mathisis or VDSTS Software ($200).  This adjustment is pretty much equivalent to what an idle mixture screw on a carburetor does.  That said, I think it will help you if you have stock intake.  If you're running lean everywhere, especially at top end, it won't do much.  But if you've got lean pops at low RPM it can make a big difference.  My stock '03 800 had lots of stumbles and rough spots at and below 4k.  I reset the TPS, adjusted the idle mixture, and synched the throttle bodies.  It runs very nicely now.

You can get the above three things adjusted at a dealer, get them done at the same time.  If you want to do it yourself get the VDSTS software from Technoresearch and a good manual.  Your mileage may go down.  Mine went from about 50mpg to 42 but it runs so much better.  With a properly tuned PC3 you can get performance and mileage, unless those nice mods make your throttle hand heavier

Scott

[Gimpy]

Yeah I should have mentioned that.  The airbox and intake are stock, but I am running a pair of after market cans on the exhaust.  I'm not sure which ones.  They kind of look like termi's but they don't have a sticker.  Or any other markings for that matter.  They were on the bike when I bought it.  The PO was extremely proud of them but had no idea what they were and seemed a bit perplexed that there was more than one option for after market exhaust.   

[Howie]

If the intake is stock and you only have slip-ons just a CO trim adjustment should work.

[944SSie]

I would say that if it is running fine and you only have a problem because you checked the plugs, put the plugs back in and just ride the thing.  Bring it to the dealer (or do it yourself) and have them bump up the trim number, set the TPS, synch the throttle bodies and check the belt tension.  The latter three things have a pretty major effect on smoothness and drivability.

[Gimpy]

Well it's time to change the belts and check the valves anyway.  So I'll get that done and then ride it in for the adjustment.  I don't think I'll be buying $200 software to do it myself.  Hopefully the guys at the shop won't charge too much.