TL1000 Frequently Asked Questions
Part III

ECU trouble codes

The TL1000 has a self-diagnostic feature to troubleshoot problems with the fuel injection system. If there is a problem with the fuel injection system, the letters "FI" will appear in the coolant temperature LCD screen. The trouble codes can be accessed by using a jumper on the "dealer mode coupler", which is a white connector with a rubber cap on the right side of the bike, under the right frame cover. The wires are long enough that the connector can be routed into the storage area for easier access. This is the same connector used for throttle position sensor calibration. With a jumper wire in place, the trouble codes are as follows:

c00 No defect
c11 Camshaft Position Sensor (CMP sensor)
c12 Crankshaft Position Sensor (CKP sensor)
c13Intake Air Pressure Sensor (IAP sensor) *measures intake "air pressure", or engine vacuum*
c14 Throttle Position Sensor (TP sensor)
c15 Engine Coolant Temp. Sensor (ECT sensor)
c21 Intake Air Temp. Sensor (IAT sensor)
c22 Atmospheric Pressure Sensor (AP sensor)
c23 Tip Over Sensor (TO sensor)
c24 Ignition Signal (#1)(IG signal #1) *front cylinder*
c25 Ignition Signal (#2)(IG signal #2) *rear cylinder*
c31 Gear Position Signal (GP sensor)
c32 Injector Signal (#1)(FI signal #1) *front cylinder*
c33 Injector Signal (#2)(FI signal #2) *rear cylinder*
c41 Fuel Pump Control System (FP control system)
c42 Ignition Switch Signal (IG switch signal)

Notes: The failure of the camshaft position sensor (c11) will allow the bike to run, but once engine stops, engine can not start. If the ECU receives a trouble code for the crankshaft position sensor, the bike will stop running and cannot be re-started until problem is corrected.

(Submitted by Brian Faulkner) — [Index]

ECU Enhancements

Greg S. ( writes on August 26th, 1997:

Heres a reply I got from DynoJet Today... Besides the power increase, The fact that the bike would run like it is supposed free and smooth is worth the price of admission.

The Power Commander will retail for $349.95 and will be shipping in early September, 1997. For more information please contact Mike Cory at +1 (800) 992-4993.

Note also that Suzuki is offering a replacement ECU, as of Sept-1997.

(Submitted by Brian Faulkner) — [Index]

What about Front brake upgrades?

The easiest and cheapest way to attempt to upgrade your brakes is by mounting aftermarket brake pads. Galfer's green-compound and EBC's HH-compound pads have good things said about them. You will need to give the pads a couple hundred miles to gently "bed-in", that is conform to the rotor surfaces and high-temp-cure on the bike.

That said, motorcycle manufacturers take great pains to match brake-rotor material with the best pad composition. They want optimum performance plus reliability and longevity that won't generate warranty claims or lawsuits. Consider your chances of buying at random a better-than-factory pad material given such extensive testing. At least one TL lister (Roger Lamb) experienced warped rotors after mounting EBC pads. What is it worth to you to have the peace of mind that comes with stock pads?

Your second option will be aftermarket brake hoses; kevlar or braided stainless-steel. Goodridge has sold a lot of kevlar lines but Galfer is the hot new ticket and both have kits available in various colored lines and anodized fittings. Stainless lines are nice but be sure to buy a set with a vinyl covering and sealed ends. These too are sometimes available in colors. "Fast-Line" (available through White Bros.) is reasonably priced and good quality. "Race" systems (lines from calipers both directly to the master cylinder) are popular because they're easier to bleed but OEM-replica and longer-than-stock systems can be custom ordered.

The deluxe option is upgraded calipers, usually 6-piston double-action type. The 6-piston calipers from the '96-97 GSX-R750 bolt right up on the TL (Kawasaki used these same calipers on several models as well). These calipers obviously use different pads which you'll likely have to buy seperately at $26-89 per caliper. They also take a 5/8" (15.9mm) master cylinder. This larger master cylinder has 23% more area than the stock 14mm TL part giving less lever travel and better feel than the stock part would. Performance Machine (USA) and Harris (UK) both make aftermarket 6-piston calipers. Lockheed and Brembo both make various master cylinders but all these aftermarket options are very expensive. Even the Suzuki parts cost $900 new but you can find used ones from parts breakers or in the race classifieds. Be careful to avoid buying stolen parts; the people you keep in business might take your bike next.

If you choose all Suzuki parts, you'll have little to worry about.

Chris Denzler warns: "If you are considering replacing the brake lines with aftermarket lines, there are several configurations available. The stock configuration (one hose to the right caliper, and a hose running from the right caliper to the left) causes the *left* brake pads to wear more quickly than the right. I don't know why this happens (it doesn't seem like it should!) but it does. I'd recommend any symmetrical configuration of the lines over the stock setup."

(Submitted by Kai Tiffany) — [Index]

What about gas in the oil?

This is a strange one. Many, if not most, of us have observed our oil levels rising over time. Upon draining, the oil is very thin, and often smells of gasoline. One lister spent $135 having his oil chemically analyzed only to discover that, indeed, it contained gasoline.

So far, it appears that Suzuki is denying this problem exists.

Conjecture is that the cause is poor ring sealing (possibly from an over-long break-in period) allowing gasoline to slip by the rings and into the crankcase. Another more likely possibility is that the ECU leaves the injector bodies pressurized when the ignition is turned off thus allowing raw fuel to eventually leak into the cylinders.

Best advice is probably to change your oil more often than you ordinarily would.

On Sept 16th, 1997, Russ Parker ( wrote:

I spoke to the Suzuki TL specialist again today — here's the deal: excessive combustion byproducts in the oil are caused by two major things on the TL.

  1. As many of us have suspected, the ECM is a major contributor to the gas-in-the-oil problem. Blow-by, map problems, etc. The new ECM will dramatically improve this situation, by eliminating FI problems as a factor. Get the new ECM.

  2. The TL was designed to stay cool (temperature-wise) while being ridden hard. Consequently it takes a long time to warm up. If you ride your TL on lots of short trips, at a relaxed pace, the engine never fully warms up. This will cause a mess. Ride it long, ride it hard.
Neil Pearce ( writes:

Greetings all from the land of OZ. I have discovered a couple of things which may be of interest:

The fuel in oil syndrome can be avoided by the use of the fast idle lever every time you start the bike — not just when it's cold. Apparently the bike tries to keep itself operational when the rpm drops below 300 by flooding the cylinders with fuel. Unfortunately some of the older ECUs get confused and dump the fuel when the bike is not even running. Turning the fast idle to full BEFORE turning on the ignition stops this on most models.

I at first did not believe this but a few tests of my own proved this to be the case. When starting the bike without the fast idle, oil level rises, plugs get fouled, starting gets harder.

(Submitted by H. Marc Lewis) — [Index]

Gas mileage

You'll never get 50 mpg. Live with it.

Seriously, your mileage will improve as the bike gets broken in. The ECU upgrade and a careful and proper TPS adjustment will improve your mileage significantly compared to the early shippment bikes. Expect to get in the 35mpg (40mpg British, 15km/liter) range, plus or minus, depending upon how you ride.

(Submitted by H. Marc Lewis) — [Index]

Modifying the Stock Exhaust

HamNeggs writes:

RE: mods to stock cans. I have modified mine, here's what I did:

  1. The stainless end caps are held on with cap screws that are spot welded in place. I filed the spots, unscrewed and removed the end caps.
  2. I then cut the end of the muffler open around and close to the baffle.
  3. Now this is the tricky part because the baffle is welded to a center compartment. I used an air hacksaw to cut away section at a time until through the end plate, from here you do what you like, I used a gas torch to slowly cut down the baffle almost to the center plate. (note I am a panelbeater and I wouldn't suggest this for Joe Blow)
  4. Now depends what you want, Loud was my first thought so I just welded a larger than stock end pipe into the end plate. Result: too barky (in low revs it sounded like a Harley) I didn't like it, I wanted more of a Duke sound.
  5. I then chose a larger than stock baffle that would slip over the remains of the stock baffle inside the can, that also was a snug fit to the new end pipe I just welded in place. Result: more like the duke thump but fluffy at idle.
  6. I then cut the baffle down at the exit end and replaced this section with pipe of same diameter (I now have 50/50 baffle/pipe)

Result: awesome throbbing duke sound. P.S. I took both pipes off to do all this work.

(Submitted by — [Index]

Oil weeping

I don't know much about this personally, as my TL doesn't have the problem. It is reported in a small but significant number (4%) of TL Registry entries, however, that oil sometimes leaks from a small drain hole below the water pump. My TL doesn't seem to have a drain hole there that I can find.

A few others have reported the right side engine cover (the large round one) sometimes weeps a bit of oil. Conversation on the TL List suggests that machining a tiny bit off the cover on the right hand side of the engine allows the rubber O-ring to seal better and cures the problem. There was one report that Suzuki in Europe was spec'ing a new, larger O-ring to the same effect.

(Submitted by H. Marc Lewis) — [Index]

Oil: synthetic vs: petroleum

There has been quite some discussion on the TL Mailing List about this subject. Some swear by synthetics, some by pure petroleum based oils. Concern that the clutch may slip with synthetics is lessened by the many TL owners who use synthetics exclusively with success.

Many feel that during the break-in period, at least, you should stay away from synthetics because they are too good! Belief is that they don't allow the rings to seat properly due to their superior lubrication.

An excellent resource to use to form your own opinion is Ed Hackett's famous writeup on motorcycle oils. Kai Tiffany has authored another answer to this question which contains further links to motorcycle oil information.

(Submitted by H. Marc Lewis and Kai Tiffany) — [Index]

Pilion cover damages paint

The accessory "solo seat" cover that comes with all TL1000s will rub against the paint when mounted in place of the passenger seat. Some claim the box it comes in contains strips of clear plastic you can install to prevent this paint damage. Brian says there should be 5 squares of clear plastic in the pouch with the owner's manual. Mine didn't come with anything like that, and my paint got damaged.

Some have reported using weatherstripping on the inside of the cover and have not experienced paint damage with that technique.

(Submitted by H. Marc Lewis) — [Index]

'Pink Wire' modification

You can try disconnecting the "Pink" wire, which sends a varing ground in 1st, 2nd and 3rd gear to the CPU. This is to compensate for the ram air induction at speed. It leans, and also I suspect, retards the ignition in the lower gears. It won't fix the stumbles, but it helps the performance a little.

The disconnect operation should be at the connector (housing both a "Pink" and "Blue" wire) hidden under the right side of your TL. You'll probably have to loosen the fairing on the right side to get to this connector, and it is sometimes below the fresh air intake duct. Pull the connector apart, and remove only the "Pink" wire coming from the transmission. It's OK to leave it free, as there is no voltage present in this wire, only a ground potential. Don't forget to reconnect the blue wire with the connector, as it is your netural signal (ground) to the guages and CPU.

Mike Harris ( writes:

The easiest way to find the pink wire is to remove the 2 bolts holding the right side cover on. Pull the cover out away from the frame, and pull the ram air tube out of the airbox. You should be able to see a black shiny vinyl sheath going to a white 2-pin connector almost directly under where the ram air tube was. In the connector the correct wire is obvious, it is very bright pink. Disconnect the plug and use something like a paper clip or anything thin to push down on the tab holding the contact in the plug. The contact should come out easily and then simply tape it off to the connector.


On Sept 16th, 1997, Russ Parker ( wrote:

More from American Suzuki's TL specialist:

Suzuki has learned from its dealer network that some people are modifying their TLs by cutting the pink wire (gear position sensor lead). Suzuki says this is a VERY BAD THING. Here's the deal:

The ECM uses this wire for fuel adjustments (which is why you guys are playing with it). It can clean up fuel delivery in lower gears; however, fuel delivery goes dangerously lean in upper gears. Hard riding, such as sustained WOT in 4th, 5th, or 6th gear can cause severe engine damage.

Suzuki strongly recommends that the pink wire remain connected. The new ECM will correct any problems that might have been ameliorated by the severing of this lead.

(Submitted by Terry Ward-Llewellyn) — [Index]

Do I need a race stand?

You do, since the TL1000 does not have a centerstand. Oiling and adjusting the chain is a royal bitch without a so-called "race stand" — which is a device for supporting the rear of the motorcycle with the rear wheel raised off the ground just a bit. With it, the bike sits upright and is quite stable.

Some stands come with an adaptor for raising the front wheel instead. Special stands are available for the front only, as well as the rear only.

I use the blue Suzuki-branded race stand (rear). There are many other brands available. Many favor the Lockhart-Phillips stand as it is less expensive and some claim easier to deploy by yourself. The Suzuki stand can be used without someone to hold the bike for you, but if you slip or loose the bike's balance then it's going to tip over!

Jim Brewer ( offers this idea for a cheap way to raise the rear wheel:

I went and got a 3' long piece of 1/2" round steel stock and ran it through the swingarm pivot hole. Then I put jackstands on either side of the bike to support the round stock. This is very stable and keeps the CG ahead of the support, so the front end stays on the ground.

(Submitted by H. Marc Lewis) — [Index]

What about the Service Manual?

The service manual is a "how to" guide to servicing the TL. It describes in detail (pictures and text) the step-by-step procedures to perform any TL maintainence, from the simple items covered in the owners manual like chain adjustment, to things like how to perform electrcal system checks or how to do a complete engine tear down and re-assembly.

It also lists all of the special tools required and tolerance limits i.e brake disk minimum thickness so checks can be done.

The manual is highly reccomended if you plan to do your own maintainence.

The price for the manual is like any other motorcycle related pricing, highly variable. Mine was about $50 through my dealer. Suzuki part # 99500-39140-03E

(Submitted by John Bonk) — [Index]

Is there a slipping clutch problem?

Apparently there is, at least as of about June 1997 approximately 11% of the TL owners in the TL1000 Registry reported their clutches slipping upon occasion. The slip often occurs during an abrupt full throttle following a deceleration which invokes the Sprag clutch effect. The RPMs jump from about 4K to 7 or 8K where the clutch abruptly hooks up again. Others have reported their clutches slip more regularly, as when simply accelerating hard in the lower gears.

Several of us have shimmed the clutch springs with small washers, here's what I posted to the TL List:

" So, I ran down to Eagle Hardware and bought some washers: some stainless steel ones in 1/4" and 5/16" which were about .040" thick, and some brass ones labelled "#14L" which were .052" thick and almost exactly the same thickness and diameter of the washers already on the spring retaining bolts. [Gordon told me via personal email that he used .040" washers in his TL's clutch.] We dipped all the plates in fresh oil, reassembled the clutch using the .052" brass washers.

[The springs, BTW, I measured at 31mm (30.75 to 31.10) and they were about 18mm in diameter. There are 5 of them, and mine had a stripe of white paint on them. The dealer didn't have a shop manual for it so he didn't know what the 'official' length should be.]"

Current consensus seems to be that Suzuki may have incorrectly torqued the clutch retaining nut during assembly at about 75 ft.lbs. Rumor is that (at least in Europe) there is a Suzuki bulletin stating that using 60 ft.lbs. instead will likely cure any infrequent clutch slipping.

Percy Masiello ( writes:

Suzuki Australia have cured clutch probs on my TL # 00062 with '98 replacement part #21610 02F00. This transformed the bike, the fault was incorrect ramp angles in the clutch basket center hub allowing the engaging dogs to disengage intermittantly. The problem is most evident on TLs that are ridden hard.

Gert-Jan Kamphof ( writes:

I also had a clutch problems, which were fixed a week ago. The clutch package was made lager by placing three 2mm steel plates instead of two and using heavier springs. The back-torque-limiter still works.

(Submitted by H. Marc Lewis) — [Index]

What about sparkplugs?

Use NGK CR8EK plugs. Early production units were shipped with CR9EK plugs, later production TL's came with the CR8EK's. There's more in the Suzuki Tuning Information document...
(Submitted by Brian Faulkner) — [Index]

What about steering dampers?

About 3 months after the TL's introduction, Suzuki issued a 'recall' to install a steering damper. The Suzuki unit is non-adjustable, and was apparently packaged to minimize the shop time required to install it. Consequently, it uses the two gastank attachment bolts near the steering stem and prevents the previously easy means of raising the front of the gastank for servicing the parts underneath it.

Several aftermarket steering dampers are available, using various mounting schemes. Some mount above the top triple clamp, some below, and a few use other mounts. I use a Works Enduro Rider unit which fits neatly underneath the bottom triple clamp where it is out of sight yet accessable for dampening adjustment. Scott (another dirt-bike accessory maker) makes a similar unit which mounts above the top triple clamp. Both units are pricy at $250-300 or more but reportedly work very well.

(Submitted by H. Marc Lewis) — [Index]

What are "the Stumbles"?

The so-called "stumbles" are a problem of the 1997 TL1000S series, particularly the low serial-numbered units. The problem is in the ECU, or ECM — the Engine Control computer which, among other things, controls the electronic fuel injection (EFI). The problems occur mainly at low RPMs (around 3,200) and make the bike surge or stumble as though it were running out of fuel. The problem did not affect all bikes equally — some were horrible, and some weren't bad. And of course some owners were more tolerant of the problem than others.

At first, Suzuki (and some, but not all, Suzuki dealers) seemed to deny there was a problem, then reversed themselves and started offering 'upgraded' ECUs to those who complained. There were apparently at least 3 revisions of the ECU, all of which unfortunately had exactly the same markings on them so they couldn't be distinguished visually.

It is believed that the ECU uses a potted EPROM which is not reprogrammable without removing the EPROM itself. Thus it is not known what, exactly, was done by Suzuki to the 'modified' ECUs. Speculation is that there is an undocumented serial port connection which may allow modification of some internal parameters which could affect the operation of the ECU.

In any case, many of us with low serial numbered TL1000S' (mine is 00136) had their ECUs replaced under warranty and felt marked improvement in the low speed running of their bikes. Some had the ECU replaced twice.

The ECU replacement, coupled with the 22-page Tuning Supplement procedures seems to have reduced the problem to a mild annoyance. With the original ECU in place, many TL owners reported their bikes stalling in traffic or when making parking lot turns — situations which on occasion resulted in accidents or tip-overs.

In September of 1997, Suzuki sent letters to all registered TL owners in the USA offering their appology and a 'new replacement ECU' which they say will make the bike just about perfect ECU-wise and be much less sensitive to drifting out of tune than were the original few revisions of the ECU.

(Submitted by H. Marc Lewis) — [Index]

Suspension adjustment suggestions

Marc Alexander writes:

I'll give you the suspension settings I'm now on that work best for me so far with the stock TL1000 and a rider who is 5'11" and 80kg. I'm really enjoying being able to adjust everything and get it near perfect! No slapping, twitchiness or anything...

Note that these settings are for my stock TL suspension, other stock ones should be similar, but any modified ones will be different. I'm not a real suspension guru! I'm just studying and testing it, setting the rider weight sag around 30% of travel and been testing different changes. I'm writing all the changes down and retesting, to help study it.

Don't think that the TL's suspension is at all _bad_!, I love mine and it's one of the best handling bikes I've ever ridden. It's just that it can be turned into a bad handling bike, like most late model bikes with fully adjustable suspension. The Suzuki factory settings are not very nice, especially as they have too much compression damping front and rear. Combine too much rear compression damping with huge throttle response and rear weight bias and it provokes twitchiness under power.

TL suspension issues:

  • Fork springs too soft.
  • Rear weight bias. Needs higher rear and lower front to compensate.
  • Rear preload set too low. Increasing helps fix above.
  • Rear Comp damping too stiff on std. factory settings.

Twisty, medium bumpy road setup:

Compression 1 1/4 turns out
Rebound 5/8 of a turn out
Preload 4.5 lines showing
Also forks raised 3mm in clamps
Compression 4 3/4 turns out
Rebound 2 3/4 turns out
Preload 177mm spring length
(10mm thread showing)

These settings worked well for me on the twisty, medium bumpy road, but recently I took the TL to a racetrack ride day, and it really highlighted the difference between a road with bumps and a fairly smooth track. On the bumpier road, the stiffer and higher front was needed to help soak up the bumps. For the smoother track, the settings above were a bit too high on the front, and didn't turn in as easily as I hoped. The front end felt quite remote and too high in the corner. The rear weight bias on the TL means it's best to get as much weight on the front as possible.

I dropped the front preload and compression damping to get the front lower, with really good effect. I went a bit too far reducing the front compression damping, making it bottom out too much under brakes, and then turned it back to 1 1/2 out. Near the end of each session, under power out of corners, the rear end was moving around more as the rear rebound damping went off, I expect from the heat of the pipe next to it, and just being used. I turned that up too.

Smoother racetrack setup:

Compression 1 1/2 turns out (reduced 1/4 turn)
Rebound 5/8 of a turn out
Preload 6 lines showing (reduced 1.5 lines)
Also forks raised 3mm in clamps
Compression 4 3/4 turns out
Rebound 1 3/4 turns out (increased 1 turn)
Preload 177mm spring length
(10mm thread showing)

There's a real tradeoff with the soft fork springs on the TL, I've found that the front compression damping needs to be set just right to not make it too stiff, but still prevent the forks from bottoming out under brakes too much. Soon to come will be a fork revalve, and especially new springs, but I'll make sure it's done without raising the front any more than it is. If I have to, I'll raise the forks further (to 5mm instead of 3mm) to compensate. The result of all this is more neutral steering, a good reduction in in the 'bump steer' that it had on the std. tyres. I noticed that bumps and camber changes used to make the front end and bike try to stand up. It's not totally gone, but much better. The rear end feels a lot better, and not as vague as before, especially under power. It's no more unstable or twitchy, either. I have the Suzuki steering damper installed.

Now the preload is fixed, the rear feels great, and I'm happy with the damper, except that it does get hot and go off a bit with hard use, but most dampers do anyway.

Rear Preload adjustment:

To adjust the spring unit(shock) preload you need to undo the shock, and leave the linkage attached to it for removal. Undo the bolt holding the shock at the front, the bolt holding the linkage to the swingarm, then the top pivot linkage bolt next to the damper. Leave the rear of the shock connected to the linkage. (The manual says to do it this way) A bit of cursing and you can wiggle and slide the shock with the linkage still attached out the rear between the tyre and muffler.

A note of warning! The red paint on the spring is really easy to scratch when you slide the unit out!!

I didn't have a good vice, or C spanner that fit on hand, so I held it and used a soft alloy drift to tighten it. It took a while! Then I discovered I could put a bar through the front shock mount, hold the adjuster ring and rotate the top of the spring unit anticlockwise. This 'unscrewed' the top and raised the preload, a lot easier than drifting it!

At least it's easier to back off the preload with a soft drift while the unit's still in the bike.

(Submitted by Marc Alexander) — [Index]

What is the TL1000 Registry?

The TL1000 Registry is an Internet resource where owners of TLs can register their bikes and their comments about them. The Registry can be sorted and viewed in various ways, and you can easily update your entry. Passwords are used to insure nobody but you can change your entry. The service is free. The URL is:
(Submitted by H. Marc Lewis) — [Index]

What is the TL1000 Mailing List?

The TL1000 Electronic Mailing list is an Internet resource where folks interested in the Suzuki TL1000 model can communicate on a regular basis through email. This free service is run by John Sweeney (Webmaster of the Sport-Twins website), who also acts as the list administrator. Directions for signing up (or signing off) are also available online. The volume of email (as of Spring 1997) is about 24 messages per day.
(Submitted by H. Marc Lewis) — [Index]

What about TPS adjustments?

Brian Faulkner, in a labor of love, transcribed the offical Suzuki Tuning Information document, a supplement to the 1997 New Model Technical Update Seminar.
(Submitted by Brian Faulkner) — [Index]

Valve Adjustment

When removing the valve cover (especially the front), be careful. There are 2 locating pins at the top of the cover that may be fairly loose. This is not really a problem until you remove the cover and one of the pins comes loose, bounces off the inside of the cover, and straight into the oil passage leading to the crankcase. It's a nice fit in the oil passage too! If the unthinkable does happen, don't try to fish it out with safety wire. That will push it farther down into the passage. I used some very strong magnets (from an old 1 gig disk drive) stuck onto the shaft of a long thin screwdriver. This will magnetize the screwdriver enough to extract the locating pin.


If you need to change shims, take a good long look at the cam lobes and timing marks on the cam sprockets before pulling the cams. On my TL, the sprockets are installed incorrectly from the factory, so the timing marks are 90 degrees off from the position specified in the service manual when the front cylinder is at TDC compression.

After 1500 miles (you know what kind of miles. :-) the valves are all at the tight side of spec. 2 intake valves are *tighter* than the tight end of spec: 0.070mm and the minimum spec is 0.10mm.

(Submitted by Chris Denzler) — [Index]

New questions (with answers), or updated information
can be submitted to H. Marc Lewis via email.
Submissions are encouraged...

Go back to Part II