EDIT: This is getting to be a long read, so get yourself comfortable with a brew, and you might just find out how to solve your TDM900 woes.
I've been asked to compile this information a bit more, and I thank those people for their support and continued references from elsewhere in the forum, and I'm glad I have been able to help so many other TDM900 owners sort out the low RPM issue.
This introduction to the problem is from another post I made:
Sadly, it's well documented that some TDM900's are much less than tractable in low to mid range RPM.
However, it has been proven that the TDM900 can be tuned to be a very tractable machine using one of several methods.
Thankfully, you do have options available for the TDM900 to remedy the situation.
Choose which one suits your budget and/or abilities:
- make inlet and exhaust modifications, that are likely in some cases to require further tuning. e.g. after-market exhaust and filter, and/or the air-box mod (air-box mod only useful if your bike is 2006 or earlier).
. (In many cases you're well on your way going this route.)
- retune with very particular attention to throttle body vacuums and offset of the TPS, progressively retuning for optimum.
. (for capable purists)
- Power Commander III add-on, and pay for someone wise and experienced with a dynamometer.
. (cashed up enough to throw some money at it)
- Dobeck/Techlusion TFI-1025 add-on, and tune as you would a carburettor (simple enough for DIY).
. (coz I did it my way)
- apply a somewhat more band-aid method by tricking one of the sensors to cause a richer A/F.
. (snake oil is good for ya)
- any combination of the above.
. (no two bikes are the same and everyone loves farkles)
Personally I can't see any reason why someone should have to just live with it if it is an issue for them.
Five very good, low cost, tips for taming the TDM900:
1. balance the throttle bodies and set the vacuum at its highest possible setting within the advised range (see the manual, any shop can do this but so can any handy owner with the right tool... like a CarbTune,for example), [I was surprised at how much difference this made to my bike, even after the TFI was fitted.]
2. set the idle at around 1150-1200 RPM once the engine is hot. (see manual, the RPM dropping too low will cause issue),
3. adjust (final drive) chain tension correctly (see manual, so many shops seem to get it wrong for the TDM),
4. adjust throttle cable slack to higher end of advised limit (see manual, this might make the throttle tube feel a bit sloppy but the result is to smooth out your wrist input)
5. Use the right fuel. The TDM isn't a high tuned race engine; it wont make use of high RON (premium) fuels and they can cause poor low RPM running. I have found the local 91 RON to be best all-round... 95RON can get more miles per tank on the highway but can run rough around town... 98RON is as per 95 but with even worse low RPM running (and the bike can stink of un-burnt fuel). (The higher RON premium fuels are more viscous and, unless the engine is made for them, will not mix and burn as they should which causes rich running and can foul ignition plugs.) The TDM900 was designed for low RON fuels, so run them on it; the only time to go higher is if nothing else is available or the ambient temperature is often above 40 degrees C (this will prevent pre-detonation or pinking). (There's lots of information to support what I've just said, you'll even find it at the fuel manufacturers websites.)
6. lower the final gearing ratio, by changing the front or/and rear sprockets. (If you do not regularly ride over 120kph or 75mph, then lower gearing can help low end performance.) Yes, I know this is item "6" on a list of "5", but this one can be expensive depending on how you do it and your speedometer will need correcting (even more than it does from OEM). Cheapest way, with OEM 525 gauge chain, is to change front sprocket to 15 teeth and then fix the speedometer with a SpeedoDRD. If you're due for a new chain and sprocket set, the best option is front 15T and rear 43T either with 525 or 530 gauge chain; 530 chains should last longer at a minuscule cost in efficiency, 530 chains are also usually much cheaper to buy. Both 15/42 and 15/43 ratios will use the same chain length as the OEM 16/42; that is 118 links. Other ratios might need longer chains, check out www.gearingcommander.com to explore your options.There are other options for speedometer fixing, like the SpeedoHealer, and I have only listed the SpeedoDRD because it's the cheapest option and I know it works on my TDM.
... and now back to the
Dobeck Performance "TFI-1025" EFI Tuner For The Tdm900
(If the fixes above haven't fully cured your problem.)
The Dobeck Performance "TFI-1025" EFI Tuner is a simple add-on device that adds fuel by extending the pulse delivered to the fuel injector for a given set of parameters. It does not remap the EFI. It does not need to be tuned on a dynamometer. All adjustments are made with small screwdriver; no computer connection is required.
You may also find these units with different branding or re-branding; "Techlusion" and "StainTune" are others I have seen.
You can get them from their website, some bike stores, and eBay by searching for "FI-1025".
Pricing starts around US$150.
The advert will usually be for another bike model, but any of the TFI-1025 will fit the TDM900.
From their website:
" Mark Dobeck, founder of Dynojet, the same person who introduced the jet kit and the inertia dynamometer, formed a new company called Techlusion in 1997. The focus of the company was to develop a controller as a fuel solution for EFI vehicles..."
Dynojet manufacture the Power Commander products.
There are installationand tuning instructions on the website, and included with the packaging.
I deviated from the recommended installation, because I'm not one to do work I don't have to, so I removed the need to lift the petrol tank. Rather than install the wire-taps near the injectors I installed them near the ECU; because it's a whole lot easier to get to and makes it all quite tidy. (Buggered if I was going to pull all the fairing apart when one side is enough.)
I'm not a great fan of wire-taps, but the ones supplied are the better type. My intention is to splice the loom when I'm completely satisfied with the device.
I first installed the device almost three years ago when the bike was stock. Since then I have added K&N filter; Fuel Exhaust mufflers; and reduced the final drive ratio, so I figured it was time to revisit the tuning as we're coming out of winter... and I'm glad I did. The result is a very tractable ride.
Originally I left the O2 sensor connected and the first pot/screw of the FI-1025 set to zero; this leaves the TDM to set the A/F mixture.
From new, with the ECU and O2 sensor setting the A/F mixture, my 9'er was bit of a pig around town. Practically no cruise under about 3700 RPM, it tended to gallop or hunt. Roundabouts and slow turns were a full on effort of clutch and throttle micro-management, and a slip-up would deliver the chug-a-chug-oh-fuckit moment that an alarming number of 900 owners curse about. I even bought a second bike just for around town.
The air-box mod made no discernible improvement to my bike. (Graeme, who also owns an '09 Australian TDM, has reported much the same... so maybe this is model specific, who knows.) EDIT: It is now confirmed that 2007+ models will not benefit from the air-box mod, see JBX's great TDM compendium for details.
Recently I experimented with disconnecting the O2 sensor. I was surprised to find the engine ran even leaner. This means that a poorly functioning O2 sensor will cause lean running on a TDM900. (Some other EFI designs will run richer when the O2 sensor fails; presumably to prevent damage to the combustion chamber, and preserve tractable performance.)
Since taking the O2 sensor out of circuit and tuning the A/F using the first screw on the TFI-1025, I can now cruise at any speed in any gear with steady RPM and linear power/torque delivery. The engine will pull smoothly from about 1500RPM, so it is now possible to do things like: slowly approach blind intersections at near idle and then pull away smoothly; confidently run at idle around pedestrians; shift and short-shift at practically any RPM without having to avoid the old "Zone of Dread" that once resided between 3000~3700RPM; cruise at low revs in traffic; and generally stay off the fecking clutch lever unless I'm actually changing a gear.
The O2 sensor can be disabled by either: unplugging it (under the left frame cover); or cutting the wire near the ECU; or pulling the pin from the ECU plug (see JBX's site for the air-box mod, for details on how to release the pin from the plug).
I wish I had removed the O2 sensor three years sooner!
Check your model specific manual for wire colours and plug pin numbers etc.
If you have access to an exhaust gas meter, you could set the A/F ratio using the dash CO settings after disconnecting the O2 sensor; but this is not practical for most DIY owners. This device is an accessible option. EDIT: but usually only found in better professional workshops.
This is the unit installed and stowed away, only the wire-taps are visible below the stock ECU:
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Unplug the ECU and you can just see the unit in its hiding spot, it's stuck there with some self-adhesive Velcro. It's a neat fit between the ECU and the splash gaurd:
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Here's the unit hanging free from its hideout:
I cut the wires short to be tidy. But, if you wanted to, there is enough wire to mount the unit on your dash/bars for on the road (seat of the pants) tuning runs.
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For easier tuning, I stuck an extra piece of Velcro to the ECU. Here you can see it with the cover off:
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And a close-up:
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They also manufacture a plug-n-play unit for the TDM900, its got a pass-through injector loom plug and socket on the loom and uses buttons instead of screwdriver adjustments. Se it here LINK. It is part number 8120094. EDIT: Although they say "plug-n-play", you will have to lift the fuel tank to install it; so IMHO the TFI-1025 is the easier unit to fit.
Tech/R&D at Dobeck Performance informs me that "The Gen 3.5 unit has the ability to take away fuel and add. Whereas the Gen 3 can only add just like the TFI kit."
This means the later (3.5) product is closer to the PowerCommander in its function, at a fraction of the cost... but you'll need a dynamometer and an exhaust gas analyser to make full use of the extra function... which IMHO is completely aside from the simple cost effectiveness of the TFI-1025, but it's your money.
The Gen 3.5 unit cannot be switched like the TFI-1025, to give a dual map mode. (Method explained down the page.) However it is possible to produce the Gen 3 kits to be plug-n-play and switch-mode-able... stay tuned for more info on this.
Edited by AzzA, 24 May 2013 - 10:59 am.