2000 sabre 1100--backfires from idle to 60% throttle on rear cylinder-runs strong from there to full throttle. tried seafoam, spark blue and strong at all wires.9k miles on bike, drained bowl no sediment. whats next????

I have a 2007 Honda Shadow Sabre VT1100 and I also put after market pipes on it from Vance and Hines. I also have to keep it choked when first starting and sometimes even hold the throttle a bit while it warms up. The bike has two carburetors and the best solution I have found by lots of asking around of mechanics and bike folk is to get it rejetted through Dyno Jet. It is meant for bikes with after market exhausts and much less back pressure from the lack of those stiffling baffles in the stock pipes. I have also noticed the power loss in the middle torque range and backfiring because of the bike running in a lean condition. The Dyno Jet website is a good place to find the correct set and corresponding part number, but then I suggest finding a cheap place online so you avoid retail price :) Hope this helps. Oh, and don't forget to buy two kits...we have two carburators in our bikes.

bike is 10yrs--carbs are varnished and dirty-clean the high speed jets-u need a clymer manual

try switching the position of the two coils, the plug wires will unscrew off of the coils and that way you dont have to pull the spark plug wires too,(be sure and change the 2 wire couplers too) if your front cylinder stops firing you know its the coil, if the back cylinder still doesn't fire then your coil is good and you either have a bad #2 spark unit or a bad crank pulse generator.

run some seafoam in the fuel and see if that fixs the problem it sounds as if the carbs are dirty from the ethenol in gas

I would check spark plugs first then if that does not solve the problem. ( GAP AND SPARK) Then lean the carb out. If you recently moved from a lower or higher altitude place then you will need to have the carbs set right for the place that you are going to be riding. The backfiring is an ignition that happens after the combustion in the motor. The gap in the spark plug could be too small or not existent causing this or its the mixture of fuel/air. This would be my first step for solving this problem. After you try this let me know how it runs...

Backfiring can be caused by fouled spark plugs (you have four,two per cylinder), bad spark plug caps, bad air cut valves on the side of the carburetors, but most likely leaking exhaust gaskets. I am guessing that you have changed the exhaust system but did not put new crush o-rings between the cylinder head and the head pipe. You should also change the tubular gasket/seals between the head pipes and the mufflers. If this does not fix the problem , take out the two screws that hold the air cut diaphragms in place and remove the covers . If the rubber diaphragms have holes in them or have become sticky they need to be replaced. Air cut diaphragms turn off the fuel during deceleration to prevent back firing. If they go bad they can cause poor running , popping , and back firing during normal operation.

It sounds to me that your carbs might be a little gunked up - you mentioned the gas may have been old, so it's possible that the smaller (idle) jets are slightly plugged up. Fresh fuel might do the trick and/or you could try using a fuel system cleaner and water remover. This problem might 'solve itself' with a little time.

As far as the backfire - this might be either from the carb issue or it could be related to that rattle you mentioned - you could have a loose connection at or near the head - this can **** air and cause a backfire.

I hope this helped!

i think you are on the right track, i would try draining and refilling tank with fresh gas,if it doesn't help, then likely the main jet has become partially clogged from improper storage or may just be, have you tried running on partial choke to see if it helps, this will comfirm a high speed lean mixture, you could try running a good fuel system cleaner b4 tearing carb apart, i like using a product called seafoam, cleans carb and carbon from engines. 1oz. pergallon. just be happy you only have one carb to mess with my vmax has four, yikes!!!!!!!!!good luc, feel free to e-mail me
[email protected]

Try cleaning the carbs ,could be bad air supply or blocked idle jets .These jets have very small holes and you will need very fine cleaning wires .Nozzel cleaners the type used to clean out oxy / acetylene nozzels are great for this job.

your idle jet's is blocked