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Bike running smoother in rain?

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by RedWings01, Apr 15, 2016.

  1. Hello,

    I have a 2001 Honda VTR250 that has some issues. I've noticed that when I ride, it will feel like its running rough. Its like this most of the time but the few times I've ridden in the rain it has run very good. So good that it felt like it had 30-40% more power. The throttle response was very good and overall it felt like it ran a lot smoother. This 100% only happens in the rain and I have no idea why.

    Any ideas?

    I'm a bit of a noob but also when the bike is idling in neutral and I give it a rev, you can hear the bike revs go up but when it comes down it feels like its about to stall and cut off but it doesn't and recovers. Also I noticed if you rev it, let the rpms drop then rev it quickly again it pretty much fails to do anything and you can hear the bike splutter. I'm not sure if this is related to the issue above. Also if I turn the choke on full then shut it off about about 20 seconds or so the bike feels like its about to cut off and sometimes it does.

    Also, there is no tachometer so I can only tell by the sound of the bike what the rpms are at.

    I would love to fix these issues myself if possible. Thanks for your help.
  2. #2 cjvfr, Apr 15, 2016
    Last edited: Apr 17, 2016
    The air is denser when it is raining, on a carb bike that probably means that the bike runs a bit richer, i.e. the fuel to air ratio becomes higher, more fuel for the same air. You may need to get the carbs tuned to be a bit richer in the dry weather. There is a mixture screw on the carbs that you can adjust, be careful if you do, make small adjustments on all the carbys the same amount and remember where the default position was.

    All the other signs would appear to be carb adjustment issues. You can tackle it yourself but if the bike is your only form of transport then it may be best to get a carb specialist to look at it for you. There is a possibility that you get the bike so it doesn't start. If you are looking at the carbs then you should get a rebuild kit which consists of gaskets, rubber O rings etc, things that perish with age. I believe they are Keihin carbs but the VTR changed carb models over its life so you will need to check the model of carbs you have.
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  3. Thanks for your help. Hopefully it is the carb and not any other issues. I will try and attempt it myself. Also great idea on the rebuild kit.