cruiser650 Posted September 12, 2009 Share Posted September 12, 2009 Have recently bought a XVS650 dragstar with Vance and Hines exhaust, Hypercharger, rejetted carbs. Seems to go well enough away from the lights. Doing about 44 to the gallon at the mo. Only problem is there's load of vibration on acceleration accompanied by the large amount of exhaust noise !! Lovelly !! Is this normal on a V twin ? Would the carbs need balencing ? Feels like it's shaking it's self to bits. Have heard on Fixya website it could be loose pistons ?? rings worn ?? Just want to make sure I'm not harming her so early on !! Link to comment Share on other sites More sharing options...
Ttaskmaster Posted September 14, 2009 Share Posted September 14, 2009 Doesn't sound right to me - Get it looked at, if I were you. Link to comment Share on other sites More sharing options...
Warhead Posted September 14, 2009 Share Posted September 14, 2009 Sounds like loose piston, check engine mounting bolts to see if any are loose just incase- loud exhaust sounds like a v-twin Link to comment Share on other sites More sharing options...
cruiser650 Posted September 14, 2009 Author Share Posted September 14, 2009 Thanks for the replys chaps. If I use a compression gauge this should show me if one cylinder is worse than the other would'nt it ?? Unless they are both knackered !! Anyone know what the compression figures should be ?? Thanks. Link to comment Share on other sites More sharing options...
cruiser650 Posted May 10, 2010 Author Share Posted May 10, 2010 Hi again, More help required ! Still vibrating on acceleration and on last cruise got 50mpg. Decided to buy carb balencing gauges to see if that may be the problem. Bought a Haynes manual but still unclear as it shows how to connect them up and then says "adjust carburettor No1 to match No2 by turning the synchronising screw(see chapter 3)" Chapter 3 menions the pilot screws ,which I assume are the two nylon headed ones on the right hand side, but then says to make sure the carbs are sychronised before adjusting the pilot scews ! Not very clear but am I right in thinking I'm looking for one synchronising screw to balence the carbs ? If so anybody found it ?? Thanks, Gra. Link to comment Share on other sites More sharing options...
Ttaskmaster Posted May 11, 2010 Share Posted May 11, 2010 50mpg?? I average 48. Link to comment Share on other sites More sharing options...
cruiser650 Posted May 11, 2010 Author Share Posted May 11, 2010 50mpg?? I average 48. Ahh, thanks for that, means I'm getting about average then. Think I've found the carb synch screw. On the left hand side between the carbs, buried right deep in the middle. Cross headed screw and looks like a spring behind it. Will update next week when the vacuum guages arrive. Just to note, this bike is a 1997 and looks like the vacuum hoses to the hypercharger have never been renewed as the larger one had "cuts" in the bend and the small one to the front cylinder inlet manifold had a 10mm split in it as it joined the manifold !! Couldn't have helped with the vibration sucking in air ! Also noticed that the airbox that fits ontop of the carbs was not fitted correctly, on one the metal strap was not fitted and the other one the rubber lip was not on the outside all the way round, quarter had folded into the inlet. Again not an ideal seal. As I said, will update once the guages arrive. Thanks, Gra. Link to comment Share on other sites More sharing options...
Ttaskmaster Posted May 11, 2010 Share Posted May 11, 2010 Think I've found the carb synch screw. On the left hand side between the carbs, buried right deep in the middle.Cross headed screw and looks like a spring behind it. Are you sure it's the sync screw and not the idle adjuster? Link to comment Share on other sites More sharing options...
cruiser650 Posted May 11, 2010 Author Share Posted May 11, 2010 Are you sure it's the sync screw and not the idle adjuster? THAT'S IT !! that's the one I meant, the smaller one, sync screw. What a great picture--very hard to see on the side stand in the gloom !! Great informative site ( http://www.650ccnd.com ) for the Dragstar--Thanks Ttaskmaster. Link to comment Share on other sites More sharing options...
Ttaskmaster Posted May 12, 2010 Share Posted May 12, 2010 What a great picture--very hard to see on the side stand in the gloom !! Buy a torch. They're cheap as chips these days, 'specially them LED ones. Link to comment Share on other sites More sharing options...
cruiser650 Posted May 23, 2010 Author Share Posted May 23, 2010 Buy a torch. They're cheap as chips these days, 'specially them LED ones. Thanks Ttaskmaster touch bought ! Carbs balenced, was 10mm out on gauge and seems to have made a difference. Two hoses to the Hypercharger, which were both split, renewed and no more backfiring. Seems a little less vibs now so heading in the right direction. Also noticed the inlet rubber manifolds from the carbs to the heads had cracks in them so covered with high temp. gasket sealent-- seems to have done the trick. Thanks again for all your help. Link to comment Share on other sites More sharing options...
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