Hi, I’m Steve Matthes 2000 Mount Morris, 125 class mechanic to the stars. I get a lot of questions about throttle cables and throttle actions on four strokes you know. As you know it has a push and a pull, the carburetor or fuel injections, throttle cable system remains the same. For this week, our insurance will show [Sp] how to presented by BikeBandit. I’m gonna take you through a replacing of throttle cable on one of these new modern four strokes. Stick around I bet you’ll learn something.
All right, first place you want to start when you’re gonna redo your throttle cable is appropriately enough at the throttle housing. A little trick you can do just go down to your local hardware store, replace these Philips screws that come stock with some bolts that have an eight-millimeter head on them, just make sure you get the same length. Get an eight mil-head on them that way you won’t strip them out and they’ll last longer. That was something that we pretty much did automatically on a lot of the bikes I worked on. And then take your throttle housing off. And we’ll go through cleaning that. Also you’re going to need your seat off and your tank off. So let’s get busy.
All right, seats off, disconnected the fuel line. On some of the EFI bikes you can just pull the tank aside to get to it. This one’s carburetor, I’m gonna take this right off. Probably a good idea to do on the carburetor bikes. Turn your fuel nozzle down on your carburetor so nothing falls in there. As well, take one of your bolts just stick it in your fuel line like so, so nothing gets in there as well.
Okay, so now I’ve got the carburetor exposed, the cables that come off and you can see these bolts over here on the carburetor. Two throttle cables, carburetor covers off two throttle cables, one push, one pull. Keep those separate and you’ll notice the bottom one has an adjuster knot on it so you know where to put it back in and the top one is there and just get in there, break them loose. Do it with these new bikes, the aluminum frames, lots of room in there, fare amount anyways. All right, I’ve broken that adjuster, slide it off, reach in there, pull the cable like so and this one will just unscrew.
Once you have that one. And you have some play in your cable, you can get in there, excuse me camera. All right, there you go. The push and the pull have been taken off. Now pay special attention to how your cable is routed some of them go up here in the radiators in between the radiators and the frame, some of them go on top of the radiators, some of them go in here and on this side of the number plate. Whatever it is, however it is, pay special attention to how your cable is routed because the new cable you’re putting on, you’re gonna want to do exactly the same thing because they’re made for certain lengths.
So this one comes up over here. See, we’ve got an hour or a meter on there when you disconnect. Pull it up this way, Yamaha has got to cool holder, just stand that out. There you go. Here’s your old throttle cable, and again, pay special attention to how it’s routed. Let’s install the new one.
All right, down in here you can see this to Allen key bolts holding this cab cover on as well as a couple 12-millimeter nuts for the throttle cable, so that’s going to come off next. And I think I can leave the carburetor all attached and get down in there and reach those. All right, cables removed. Let me clean this bar off really good. We’re gonna grease that up.
Now we spoke about in an earlier how to live your clutch cable. I’ve got my new throttle cable here. If you had an old one and you want it a little bit, you certainly can’t. You can do the return one, it’ll make it a little easier. Just go from the bottom end because as you can see the top as those plastics, so just go from the bottom and do the exact same thing, it’ll come out there that way. But it’s not really needed that much so.
Okay, so we paid attention to how we we’re routed, and on this bike, it was to the right of the number plate bolt. And it came down through the triple clamps, easy for me to say. Came through here, through this little holder that Yamaha had, so after I put them through, there I want to just bend that back with my finger, on top of the radiator, and down in there. Okay, that’s cut.
All right, we know that the pull part of the cable does not have the adjuster, and we know that that goes in the top. There is only one way it can go in, so go in, go ahead and screw that in there like so. And as far as the push one, basically it’s adjusted from the factory in a pretty neutral position. Any kind of throttle point adjustment is going to be done up here on the top. So you can just leave that where it is and it goes in here. The throttle cables loop around the wheel, throttle pulley. You have to be careful that you seat the knot in the right way, it will only go in one way. Let’s put the top in before we get too far here.
There you go, the cables are in, they’re aligned. Let’s tighten the bottom. All right, time to devote our attention to the top. For that smooth feeling factory throttle, we clean the bar. Now let’s clean the throttle tube out with some contact cleaner, spray it down in there. It gets pretty dirty. Now, you can use assembly lube for this. I recommend assembly lube, that’s what I did up when I was a mechanic but failing that certainly some Maxima NPPL lube will work. Spray it down in that throttle and now you’re ready to put it on the bar up here. Slowly slide it on. Then you can feel it, it’s a lot better than what it used to be already.
Now, time for the throttle cables. Again they only go one way, you can see how they butt up against each other there in the housing. So you can basically look at the throttle and realize that one goes in the front, and one goes in the back, and that’s the only way that the housing itself will go on. You can see the housing fits in like so. There we go, the housing is all together. Before you put the bolts in you can put this rubber piece on just kind of hold it together while you dig up for some bolts.
Now, I explained going to your local hardware store and getting some eight-millimeter bolts for these screws, we didn’t do that. So we’re going to have to replace the stock screws back in. Don’t tighten them until you have them both in. And then what you wanna do, what I do is take the throttle assembly push it all the way under the bar as far as you can, and then back it out maybe a couple of millimeters. And what that will do is prevent the end of the throttle to from chasing up against the end of the bar and causing stiction.
Now, throttle feels pretty smooth. There’s a little bit, not enough play in here, I got a little bit but I need more just from the adjuster. If I run out of room up here in the bar, I can always go down to the carburetor but it’s a 250F, this model, so I don’t want too much in there. And I’ve got a little bit more, there we go, take that, perfect. I got a little bit of throttle in there, a little bit of play in there. You want to give yourself a little more if you have a 450 just because of the nature of how powerful the bike is. I’m ready to go. I’m ready to put this on, reach down there, bolt it up, put the tank back on, put the seat back on and I’m ready to rip with a smooth throttle.
All right, that’s been this week’s Transworld How To presented by BikeBandit. Stick around next week you’ll see more of these things. And hopefully you’re enjoying them.