Firing both running on one
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  1. #1
    Newbie
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    Firing both running on one

    I just came into possession of a '08 vstar 650, it only had 1,000 miles on it but has been sitting in a... not so clean garage for the last three years. I had quite a bit of work done to it already (tank cleaned, carbs cleaned). I am still having the issue of both plugs firing but it is only running on the back cylinder. I swapped plugs and no change, the choke has no affect. I'm not the most experienced, and I'm at a loss. Google hasn't been any help.
    Last edited by mwahoski; 08-04-2015 at 06:46 PM.

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  3. #2
    Newbie
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    2002 Suzuki Marauder
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    Your going to have to take it in. Sorry

  4. #3
    M-J Lifetime Achievement Award
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    A simple test is to see if the offending cylinder spark plug is dry. If so the fuel supply to that cylinder is suspect and thus the carb supplying it must not have been cleaned properly or is re assembled incorrectly. A sticking float needle may be all it is....or a blockage not cleaned properly....usual suspects would be the idle circuit which has some tiny holes just after the venturi...where the carb inlet narrows...or the main jet clogged, needle clip not in, leaking diaphragm, cocked return spring just to name a few.

    If the plug is wet then then spark you see may not be as good or even present under compression. For an engine to run three things need to be present....fuel, air, and a spark. Even a poorly tuned or maintained engine will attempt to fire if these three are present. Check, also the wire and cap to the offending cylinder....sometimes they become loose cracked or damaged enough for the high tension energy to ground out to a metal part. If this bike has any resisters in the wiring...used to be used to prevent interference to TV signals...get rid of them....ditto any device on the plug caps.

    One extremely simple test is get the motor running and tap lightly on the carb supplying the offending cylinder....if it starts to run then it is very likely a sticking float or needle. you can do the same to the plug cap and wire....beware of the high voltage....whilst it is unlikely to kill it can give a bloody big jolt.

    Good luck
    Last edited by Aussie Steve; 08-04-2015 at 09:21 PM.
    Smoke me a kipper I'll be home in time for breakfast

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  6. #4
    Super Moderator

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    Quote Originally Posted by Incredible78 View Post
    Your going to have to take it in. Sorry
    And YOU are going to have to actually contribute something useful in your posts.
    Sorry.
    Don't believe everything that you think.

  7. #5
    Super Moderator

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    Quote Originally Posted by Aussie Steve View Post
    One extremely simple test is get the motor running and tap lightly on the carb supplying the offending cylinder...
    And another one is to squirt a LITTLE bit of fuel into the air intake of the dead cylinder. I suspect it will suddenly run much better, indicating that there is a fuel delivery problem with THAT carb. Gas will work; so will starting fluid or carb cleaner or propane from an unlit torch.
    Don't believe everything that you think.


 

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