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Spada/VTR250 - Poor running - splutter

Discussion in 'Technical and Troubleshooting Torque' started by hynejont, Dec 21, 2009.

  1. Looking for some assistance. My Honda Spada VT250 has developed a splutter/cough and poor idling.
    Rode home last Friday week and bike felt a little flat. Next day went out and the bike had developed a bad splutter in the 1st quater of the throttle. If you tried to gradually increase the revs whilst stationary, it would struggle and then pick up but would still idle ok. On the road if you gun it, its initially flat and spluttery but picks up - still isn't 100% though and as soon as you go to a constant throttle it splutters as if its running out of fuel. Although the splutter hasn't necessarily got worse, it now won't idle and will stall.
    I've taken tank and air filter off - done the usual carb cleaner spray, check the fuel lines and all seems okay but the bike is no better. Both carbs are drawing air okay but it definately seems like a fuel supply problem due to the fact that if I use the choke, it improves things (but definately doesn't fix it). However, it does still give an impression of an ignition/timing issue as you get that rumbling purr as if its out of timing or missing slightly.

    Basically I'm lost with where to go and have posted as Lloyd Penn was closed this morning when I went there before work.

    Any help would be much appreciated

  2. Take out your spark plugs & make sure you're getting a big fat blue spark when earthed to the engine, that will rule out electrical. You've checked the fuel lines are routed correctly & not blocked/kinked?

    Have you changed anything on the bike recently? Air filter, exhaust... What happened when it first started?
  3. your very good description tells me it is dirt under one of the float needles.

    Take it for a ride and give it some in one of the lower gears. If that doesn't fix it you are going to have to take the float bowls off the carbies and clean them.
  4. Thanks for the info. I'll give the 'low gear' trick on the way home and I'll check the spark too. Nothing has changed on the bike apart from the day before it started happening, I put E10 fuel from 7-Eleven in it. I usually put standard unleaded in it but have used E10 without issues before. May be a complete coincidence.
    When you say "give it some in one of the lower gears". Do you mean from a low speed all the way through the rev range and hold it at high revs to release the float ?
  5. Pretty much. If you lift the needle enough and flush a bit of fuel through it can sometimes dislodge the bit of crap.

    Only sometime however.
  6. Ibast - Unfortuantely "giving it some in the lower gears hasn't resolved it and I've knocked a fair few kms trying to clear it.
    Is there a trick to find out which float bowl needs cleaning or is it just best cleaning the both of them. On the Spada's. do you happen to know whether this is servicable on the bike or is it just easier to remove both carbs and clean them on a work bench ?

    Thanks for you help
  7. I have just dug out the Spada Workshop Manual (http://www.theedgeofmadness.com/spada/spada.html) and it states the vacuum chamber and float chamber can be serviced with the carburetor assembled. I'm pretty sure it will be a pain in the arse unless the carbies are removed. I shall find out when I attack it I suppose.
    Any advice is greatly appreciated.
  8. If they come off as an assembly, pull them then and take of the bowls.

    Take the float and needles out and spray some carbie cleaner about.

    Put the floats back in and set the float height.

    bolt it all back together.

    The ideal thing is to then do a carbie balance, but if you keep the two carbies together then you may get away without it.
  9. Okay...I took the carbies off as a par and removed the float chambers. Gave them a good spray of carbie cleaner in every orifice possible. I did not remove the actual float bowls however as wasn't sure how to reset the height when finished. Replaced the seals and put it all back together. Took ages to get it started as fuel was completely drained but when it did and took it for a test ride, I was a happy man ......for 5 minutes. Then the splutter came back but no where near as bad. Only just off idle throttle instead of previously where it was 1st quarter of throttle. One thing that became very evident which I noticed before but didn't think anything of it, was the noise from the carbies. The initial test ride remided me of the reletaviely quiteness it used to be coming from the carbs. However, when the splutter comes back you really notice a "whoooooaar" noise coming from the carbs and its a lot louder. Anyone have any ideas ? If its a case of removing the carbs again and the float chambers and jets - any advice of how to set the float heights would be appreciated...Thanks
  10. Did you take the float needles out? If you didn't you might be back in again.

    The height is usually from the bottom of the float (top when you turn it upside down) to the flange. You will have to get the factory setting. It is the point where the needle seats. You bend the tab to adjust.

    There are lots of websites around.

    It can also be check externally.
  11. Sounds like you may have some crap in the tank that is repeatedly finding its way into your carbs. Might be an idea to drain the tank and pull your fuel tap off to inspect the state of its mesh screens.
  12. ibast.....thanks for the help. No i didn't actually remove the float or the float needle or any of the jets. so might be worth me giving it another crack before handing the carbs over for a professional rebuild.
  13. Thanks for all your help. Removed the carbs without seperating them and then stripped them down and cleaned every jet and the floats. Whacked them all back together and to assist with starting it up, directly poured a small amount of fuel into the fuel inlet of the carbs to fill the float chambers. Worked a treat instead of the 10 minutes trying to get fuel into the carbs before starting, it started first time. Test ride and all was good. Its actually made a noticeable improvement to the overall pull throughout the revs and not just resolved the spluttering problem in the first quarter of the throttle.
    Off to get the carbs properly balanced and tuned just to finish the job off.

    For those thinking about dismantling some VD10 carbs off a Spada VT250 or VTR250 - don't hesitate as its easy and not worth forking out $300-350 to get them done at a garage