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VTR 250 poor idling and occasional stalling

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by misternyborg, Jun 8, 2014.

  1. Hi everyone!
    I need some help on my beloved 2007 VTR250, she is having some issues with her idling, and stalls occasionally.

    First some background on the bike:
    I bought the bike in April, with just over 30ks on it. The previous owner told me that it haven't been used much the last 12 months, just occasional rides. When I picked it up, it was idling poorly, and he told me it was because it was low on gas. After filling her up, she still wasn't idling perfectly though. Now I have put about 2ks on the bike, and there is no problems with the engine; except the poor idling and stalling. No flat spots or bad torque. The bike is 100% stock, no slip-ons or nothing. As for servicing, she has been regulalry serviced, although the last service I have paperwork on is at 18ks. The previous owner stated that she was serviced at 25Ks as well, but have no paperwork to show for it, so I am guessing it havent been.

    The problem:
    She idles poorly, and stalls occasionaly, usually when I let go of the throttle and she has to return to idle. This is especially a big issue when I'm riding in slow traffinc or in the city, and engaging/disengaging the clutch alot. The bike will stall and start up at once, but after 4-5 stalls the battery is out of juice and I have to jump-start her by running into gear... Which is far from ideal, and makes stopping on steep hills and riding in the city a nerve-wrecking nightmare.

    I can manage to recreate the problem when it is idling: see the video below, and you can clearly hear that she is struggling with her idling. She also idles around 1k - with the service manual stating that it should idle at 1.3k +/- 100.


    What I have tried:
    My mechanical skill and insight is limited, but I have picked up a couple of things I have learnt during my years...

    - Oil change
    Should the last service have been at 18Ks, a oil and filter change was way over due... So, I changed both the filter, replaced the o-rings, and topped her up with the genuine Honda-oil.

    - Methylated spirits in petrol

    I learnt about that trick here on this very forum, if there were to be some water in the carbs or fuel this should have taken care of that... I added about 20 mLs, one cap, but there was no difference.

    - Checked Air Filter
    Nervous and poorly equipped with a spanner-set from the reject shio and a IKEA-toolkit, I took off the petrol tank and checked the air filter - which supposedly was to be changed at around 20K-service. I have no experience with these filters, it is dirty but not clogged: see picture here.

    I also wanted to check the fuel filter, but it turned out the VTR250 does not have one. My plan was checking the spark plugs as well, but with the limited amout of tools I have I didn't stand a chance of getting them out. I am out of ideas - and this issue is really annoying me. As a student with limited funds and a will to do things myself, I really want to figure this out and fix it without dropping her off to a pricey mechanic.

    I appreciate any thoughts and ideas! Thanks!
  2. Wind the idle adjustment up until you are idling in the recommended range to start with. You may need to do a carb balance at some stage.
    • Agree Agree x 1
  3. I'd suggest that 20 Ml of metho in fuel would do next to nothing. If you suspect water in fuel try more like 200 ml. But again unless the issue is water in fuel it probably won't make a difference.

    Do you know when the bike was last serviced properly? Could be the previous owner knew they were getting rid of it and skimped on the service. May just need a decent tuneup.

    Certainly as CJVFR says start of by setting the idle into the right range and see what that sounds like.

    Plug socket is always handy. Not one in the standard tool kit that came with the bike? If not yu can probably buy one pretty cheap from Autobarn or Supercheap and it is a worthwhile investment. Just remember there are two plug sizes so make sure you get the right size for your bike (16 mm ??? from memory).
  4. looks idling is way too low. I remember that the workshop manual says idling RPM is around 1300 when it is fully warmed up. check engine oil was over filled, try adjust idling setup, change sparks if they are old. also recommend injector cleaner pouring into petrol tank a bit.
  5. Finally watched the vieo as well.

    It is definitely idling low unless due to camera angle below 1000 rpm. However i also notice the temp gauge saying cold. Are you using choke? (I assume a VTR has a choke but maybe not) I would expect a lot higher idle with choke.

    However the idle speed quoted will always be at normal operating temp. So what speed is it idling at when warmed up?

    Most bikes in winter don't like to run that well initially, so you need some choke to keep them idling but usually at a higher rate than they can idle at once warmed up. However some bikes with fuel injection and computers don't have a choke and the computer takes care of things. I suspect the VTR is not one of these.
  6. #6 misternyborg, Jun 9, 2014
    Last edited: Jun 9, 2014
    Thanks guys, I adjusted the idle, and atleast now it isn't stalling... Prior to adjustment the bike would idle just like the video, even when warmed up. I remember riding to Geelong on the freeway, and it would might as well stall when I pulled in to a petrol station. On the video it is not fully warmed up, just a small 5-minute ride. Now she idles around 1400 once warmed up, and it is much more stable than before. There is still some "shaking" in the idling though, not sure what that could be, but I will try some petrol cleaner in to too, after running out the metho. Any recommended brands for injector cleaner?

    You are correct regarding the choke and EFI @GreyBM@GreyBM, this model does have a choke, unlike the newer EFI-model (2009 onwards I think). I usually let it idle on full choke until it hits 4k, and then gradually decrease the choke. I think I'll take the advice and check the plugs regardless, none of the services I have paperwork on have changed them, so it might be due.

    Took a ride to the city today, and it was amazing to go on a ride NOT being nervous of any stalling! Such a beautiful day as well :)
    • Like Like x 1
  7. Replace spark plugs.
    Clean carb jets.
    Balance carbs.

    If it stills idles poorly after that, start looking for problems.