synchronization of the throttle body should make it go away and run smooth and pick up mileage also
How is that done? Do you mean like a dual map?
This is what he is talking about!
The easiest way to do a throttle body synchronization is as follows:
Do it after a valve adjustment, before you re-install the air filter housing and before laying the fuel tank down, in other words set the tank on the frame and hook-up the lines, but keep it raised up. This allows you room to get at the vacuum nipples and the synchro screws.
You can do it with the air filter housing on, but it takes a special tool to do so, without the housing a small slot tip screw driver will work. Except for certain aftermarket air cleaners...like a Hyper-Charger.
The Honda service manual is confusing as hell, so I will try and simplify for everyone.
First thing to do is hook up a good set of vacuum gauges or a mercury manometer to the two vacuum nipples on the intake manifold. I prefer a mercury manometer ( I use a Motion Pro Four Column) because the columns do not 'bounce' as much as a mechanical gauge does. Use the nipple for the PAIR valve and the factory 'capped' nipple, do not remove the vacuum line from the fuel pressure regulator nipple.
Let the gauges hang from the handle bars on the right side of the bike so you can easily watch them.
Next, turn each of the synchro screws all the way in slowly, until they each just bottom out, counting the number of turns as you go. Write the number down so you don't forget it. This gives you your baseline setting.
Now, back each screw out to its original position plus 1/4 turn and start the engine. Let the engine fast idle until it is warmed up, should need just a couple of minutes.
Check the vacuum readings on each gauge, start with the cylinder that has the higher of the two readings, and turn the screw IN 1/8-1/4 turn at a time, watch the gauge for a several seconds to observe any change. If the vacuum reading goes higher then keep turning the screw in slowly until the vacuum reading starts to decline.
What you are looking for here is the highest STEADY vacuum for each cylinder. Once the vacuum reading starts to decline then back that screw out until it reaches it previous high and leave it there. Usually 1/8-1/4 turn will do.
Now work on the other cylinder, turn the screw in or out until highest STEADY vacuum is reached. You may have to give it more or less turns than the other cylinder screw and that is ok. What you are trying to accomplish is to get both cylinders at their highest steady vacuum but within one or two inches of vacuum of each other.
The reason you may end up with one cylinder at say 2- 1/4 turns and the other at 2-1/2 turns is because the cylinders will be different in their vacuum pull due to differences in piston ring or cylinder wall wear, etc. This is completely normal.
The goal of this procedure is to get both cylinders as close to each other as possible in vacuum signal so the engine will have a 'balanced' or 'synchronized' intake charge. Most of the VTX engines that I do this to end up with 26-28 inches of mercury.
Do not forget to re-cap the one vacuum nipple and hook-up the PAIR valve line if your bike still has it. After you have done this once or twice it is easy from there on. And yes, most bikes will need synchronized more often than people do it. I hope this helps, instead of confusing anyone.
http://www.vtxoa.com/forums/showthread.php?t=76927&highlight=synchronization+throttle+body
