If you have a “Freedom” engined Victory and you have been noticing your performance starting to lag, your engine’s idle speed dropping lower, and lower, or, you are riding, and your bike just dies during a closed throttle situation, it may be time to clean your throttle body. It’s not that hard a job, and it is one of the little things you can do that will keep your Victory running well.
This tutorial applies to Victory motorcycles with “Freedom” engines, V92 C, TC, Vegas, and the Vegas variants, Hammer, Jackpot, and Kingpin, without exhaust sensors. The Victory pictured here is my 2003 V92 C, there may be some minor differences in equipment, but, basically the procedure is the same. Other brands of motorcycles with similar fuel injection setups may also benefit from this procedure, but, before attempting it, be sure you fully understand your brand’s fuel injection system.
The first step is to remove the tank, this is better done with the tank almost empty. You do want an almost empty tank, trust me on this, I have forgotten, topped my tank off the day before, and it makes getting it off a total bear, a full tank weighs a ton! The first step is to disconnect the fuel line going into the tank or fuel rail. I usually take my line off at the fuel rail because there is so little room under the tank, your situation may be different, so it’s up to you. There are two other connections, the tank vent line, and the fuel pump electrical connection, make sure both are disconnected before removing the tank. Before you remove the tank, make note of the routing of the gas line so you can put it back correctly during the reinstall. Something additional, if you disconnect your fuel line at the injection rail, it’s a good idea to completely remove the hose clamp before pulling the tank, it could potentially scratch your chrome or paint on it’s way out.
After you have your tank off you should be looking at something similar to this unless your air cleaner assembly has been replaced with an aftermarket item.
Remove the five screws (red arrows) holding the cover in place. This will reveal the inner velocity stacks inside the air box. The Victory shop manual calls them intake tubes, but I like “velocity stack” better.
Both stacks will have to be completely removed for the throttle body cleaning. Start with the left stack, rotate it counter clockwise as you are pulling it out.
Take your time, this is a long sucker! And, there is a sensor that it can come in contact with.
The sensor is for air temperature, it’s reasonably well protected, but, it pays to be cautious just the same. The orange item on the right side of the above image is the MAP sensor.
This is the location of the air temperature sensor, just beyond, you can see the air filter, in this case it’s a K&N performance filter. To remove the right velocity stack, rotate it clockwise.
It’s a little less trouble to remove than the left stack, again, just be mindful of the air temperature sensor.
When you have both stacks out, you should see something like this, congratulations, you have reached your throttle body! Take a cloth that is as lint free as possible and wipe out the oil and any debris before opening the butterflies for cleaning. You can also put some throttle body or carb cleaner on a cloth and wipe the area down as follow up, the idea is to eliminate anything that might get drug into the open butterflies during cleaning. From this view there looks like the throttle body is reasonably clean, not really, the real story is on the other side of the butterflies.
You are looking at a year’s worth of carbon buildup, if you have never cleaned your’s it may look worse, mine did the whole area was black with carbon. Let’s get started cleaning, first we are going to need some high tech tools.
And here it is! I find an old tooth brush works best, it’s plastic, so it can’t damage parts, the bristles can conform to clean closer, and when it gets really grungy, you toss it! But, we can’t risk bristles breaking off getting in the engine, so we use a cover.
I like to use an old cloth baby diaper, over the brush, just soak it in carb or throttle body cleaner and swab away. I tape the throttle open at the handlebar, this way I have both hands free, one to hold a light so I can see, the other for cleaning. Make sure that there is nothing that can fall into the open throttle bodies during cleaning, and, do not spray cleaner directly in the throttle body, having a extremely volatile chemical trapped in your engine is never good!
As your cloth gets dirty move it around on the brush head, if this is your first time cleaning, you might need a second cloth. Make sure you clean as much as possible, including the butterflies on both sides, and as much of the edges as you can.
When you are done it should look like this, if there is some lint, I can usually get it out with my finger, when you are done let the butterflies close and wipe the area down again to clean any remaining debris. From this point, you can begin the reassembly, begin with the right velocity stack, turning it counter clockwise as you insert it. Turn the left stack clockwise to install it, on both be mindful of the temperature sensor. They do not go back in without some effort, and you my be tempted to just leave them out, but don’t, they are an important part of your intake tuning, and they keep the oil from your crankcase breather from being sucked directly into your engine. After they are back in, reinstall the cover, after that’s done, it’s time to reinstall the gas tank. Make sure you have everything reconnected, fuel pump connection, tank vent line, and, of course, the fuel line, if you disconnected it at the fuel rail, make sure it is routed correctly, the line fully seated, and the hose clamp tight.
The next step is to test run the engine, but before you do there is one last step, priming the fuel pump. The pump is primed by turning the ignition key to the ON position, but not starting the engine, toggle the right hand engine stop switch off and on two or three times, on the last on cycle, leave it on, for a minimum of 10 seconds, then turn the ignition key to the OFF position. You may now test run the engine, start it as you normally would and let it warm up, keep an eye on the fuel line where you disconnected it for potential leaks. The first time I performed a throttle body cleaning, I had a slight leak, so I always check before I go for a test ride. You may notice that during your test ride the idle may be higher than before, this is a possibility if you have been turning your idle up prior to cleaning. If it is high, you can turn it back down, if you have a tachometer, the manual recommends 900 RPM as a good setting, if you don’t have a tach, play it by ear.
Words By: Terry Cavender
Images By: Terry Cavender