10

Lately I noticed a change in the sound my exhaust is making when decelerating from ~4000+ revs while in gear with the clutch not squeezed (that would be engine breaking probably). I'm unsure how to describe the sound with a word, but it fits with what these guys are reporting on the model forum - popping maybe would be a good word (like popcorn in the microwave, but a bit more metalic). Also according to the explanations on the forum it is behaving as expected (because of mechanical reasons I don't fully understand, but I would trust them).

Now comes the question, why did it start making this sound just lately? I have this bike since autumn and I didn't notice it until this week. Could it be related to weather? The temperatures only recently started going over 20° C (28° even, today).

Asking for: Triumph Tiger 800, from 2011, with stock exhaust (fuel injected).


Update: I took out the spark plugs and the air filter. Cleaned them a bit with a wire brush for the former and compressed air for the later. Retightened and checked all the parts I could get at following this guy's excellent instructions.

Air filter, before and after:

enter image description here

Spark plugs, before and after (all of them looked almost the same, the picture has the one that was blackest):

enter image description here

The throttle body plates I didn't touch, but they didn't look too dirty to me:

enter image description here

In the process of dismantling and remounting I managed to not connect the fuel level sensor correctly and this (probably) triggered a check engine error. I reconnected it and fixed the fuel level indicator, but the error is still showing on the dashboard.

The result of this work: nothing changed, the bike runs identical to before messing with it. But now I need to see what that check engine is on for - probably just need to erase the error, right?

  • added triumph and tiger as tags since that's the forum you were on. Is that correct? – DucatiKiller Apr 6 '16 at 14:37
  • @DucatiKiller Correct, but I didn't want to add them as it may not be relevant only to that model. – Alin Purcaru Apr 6 '16 at 14:40
  • Sure, What year is your Tiger? I believe ALL tigers are fuel injected...right? – DucatiKiller Apr 6 '16 at 14:43
  • @DucatiKiller It is. I added to the question this aspect. – Alin Purcaru Apr 6 '16 at 14:45
  • 1
    Oh yeah, +1. Nice question. – DucatiKiller Apr 6 '16 at 14:48
6

Popping

I too have a Tiger 800xc (2013) and have noticed it popping when downshifting and revs are too high for that gear. I did notice a significant difference in this behavior after 12,000 mile service, and using 91 RON fuel (not all brands and outlets are same... for me ARCO has worked best). At this point, I consider some of it as normal behavior.

From your update, considering the mechanics are OK, then a map update might help as it will also address fuel mix being too lean or too rich. That can be done using TuneECU. Tutorial and resources to work with TuneECU can be found at http://www.triumphrat.net/ecm-and-fi-tuning-help-tips-and-tricks/218346-tuneecu-for-dummies-installation-guide-and-questions-pertaining-to-installation.html#post2353942 . It is too long to be copied here, and I strongly recommend reading the whole post before beginning work with TuneECU.

TuneECU will also tell you the reason for Check Engine light being lit, however you will not be able to clear it.

Check Engine Light

From my experience, check engine light signifies that an error has been detected by the system and is stored in the ECU. Those errors can be manually cleared using software like DealerTool or similar. I suggest you get that kit (proprietary cable and accompanying software for Windows) if you want to stick with European brands and see yourself working with engine lights and flushing ABS brakes. It will also help you align your throttle bodies if they are not properly aligned. The check engine light will go away on itself after about 500 km or miles if the problematic condition is no longer there.

To check if you are dealing with one off issue, address/understand the error stored in the ECU and clear them to fix the Check Engine light. Diagnosis and resolution can be found in forums and Triumph's service manual - https://github.com/tonymorris/800xc/blob/master/manuals.md. If the same error reappears after being cleared, then you might need more work and service manual should still be able to help you with it.

  • 1
    That's a great answer +1 – DucatiKiller Apr 11 '16 at 20:22
  • Thanks for the answer! In Romania all gasoline is 95+ (at least on the label) and I mostly refuel from the same gas station next to my home. I'll use TuneECU, but I'm waiting on a FTDI cable to be able to connect. – Alin Purcaru Apr 12 '16 at 6:03
  • Update: The light went away on its own before I manage to check with TuneECU, so I couldn't see what it reported, but I'm pretty confident it was the fuel level sensor. I also updated your answer to reflect that the light does go off after a while even if it's not cleared. – Alin Purcaru May 11 '16 at 15:04
14

Sounds like a lean condition

Here's something to chew on regarding identifying a lean or rich condition on a motorcycle.

What I believe you are hearing is backfiring. It isn't loud because the baffling systems on modern motorcycles are so effective.

If you have a lean condition that suddenly appears out of nowhere I would check these basics.

  • Vacuum lines. If you have a vacuum line come off, it will add more air to the system and create that lean condition.

  • Manifolds - Perhaps one of your manifolds has a crack in it. Also, check the metal bands that wrap around the manifold and tighten down to hold your throttle bodies into place and ensure they are not loose allowing air to slip by.

  • Manifold plugs - I'm not sure if your model has these but there are stand pipes on many rubber manifolds that are brass. They will be capped off with a little rubber cap. They are taken off for maintenance and used to measure manifold pressure and synchronize the throttle bodies. Make sure the plugs are capping the stand pipes off.

  • Air filter - This one is a reach. See if your air filter is properly placed in the airbox and hasn't come free allowing more air into the system and effecting your AFR.

Anything I've missed regarding air leaks is what you will want to inspect. Vacuum lines for the emissions system, a fuel diaphragm, etc. Perhaps a torn air filter (reaching again, I've only seen that once in my life).

Edit

  • Loose sparkplug - A loose sparkplug could be backing it's way out of the threads. You can have a lean condition as it begins this process. Double check that your sparkplugs are nice and secure.
  • 1
    Does that answer also apply to injection? I see that it is written for carburetors. – Alin Purcaru Apr 6 '16 at 14:55
  • I added the link as something for you to read that might get your creative troubleshooting juices going but I wrote it under the premise of fuel injection. You will notice I used throttle bodies as opposed to carburetor in the answer verbiage. – DucatiKiller Apr 6 '16 at 14:57
  • @AlinPurcaru I think this would be the place to start. Physical inspection. If you don't turn anything up then it's pull codes but I don't imagine you have an FI light on or would have mentioned it. – DucatiKiller Apr 6 '16 at 15:38
  • Had a phone chat with a mechanic and got dismissed with "it's perfectly normal to do that". I understand that some amount of backfiring is normal, but I'm concerned about why it started doing it suddenly. So I'm going to start inspecting myself. Will let you know what I find.Thanks! – Alin Purcaru Apr 7 '16 at 8:34

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