snagglepuss27

Hi, I have a problem with my son's (restricted) 535S Virago and I've torn out virtually all the hair I have left in trying to solve it - so I hope someone out there can help: 1997 535S twin carbs and everything bog standard apart from the restrictor. 1. Original fault was not starting after a lay-off over last winter: Stripped down the carbs and changed the petrol pump because the pump wasn't 'ticking'. It was neither of those but the bike started after that - first go as I recall. 2. Now starting OK but:- Poor performance - no power and wouldn't go much above 50 mph in any gear. It seems to reach a flat spot: Inspected the diaphrams and found one was torn so Replaced carb diaphrams but no change 3. Stripped down the fuel tanks and threw away the old fuel (well actually used in the lawn mower which isn't so fussy), cleaned components and re-built. Filled with clean petrol. Starts and runs OK but no change in performance. 4. Stripped down the carbs completely No change 5. Removed spark plugs and found the rear plug was black and sooty (but dry), so replaced both No change 6. The bike was restricted so I removed the exhaust and removed the restrictor (only found a restrictor in one exhaust - does that sound right or should there be one in each exhaust - might explain things?) No difference 7. Replaced ignition coils No change - in fact possibly worse performance now. One cylinder - rear - gets hot quickly. 8. Balanced carbs Awaiting test run but I doubt there's an improvement. Point is, I would have expected there to have been SOME improvement but the fault of it hitting a flat spot (actually no acceleration beyond 50 mph remains. One interesting thing was that son was giving it some stick around the back lanes and took the throttle to at or near maximum and the bike suddenly burst into life. We could not subsequently reproduce that however. Any ideas? Is there anything left other than the ECU because I seem to have tried all of the usual Virago running problems fixes? Any contributions welcome. Cheers