If my memory serves me well, I had to take the top off and lift the filter out, then loosen the nuts that hold the thing in place to get enough clearance to fish the new fuel hose through. I used to own an '88 RS. I might have taken the carbs loose and lifted the whole thing out. My RS did not have the pulse-air plumbing in place. It's been a few years.

If my memory serves me well, I had to take the top off and lift the filter out, then loosen the nuts that hold the thing in place to get enough clearance to fish the new fuel hose through. I used to own an '88 RS. I might have taken the carbs loose and lifted the whole thing out. My RS did not have the pulse-air plumbing in place. It's been a few years.

If my memory serves me, the R series changed in '85 with the"Last Edition". The fuel lines may be the same.

So you simply loosened the nuts on the on the air box to get the hose out? Thanks

Yeah,... release the clips, lift off the top cover and filter and have a look.

Remove cover, remove filter and then there is a bolt on the bottom and a bolt on the left and a nut on a stud on the left. You may be able to get enough room to pull the old hose out and thread a new one in. If not You'll have to remove the carb snorkels and pull the airbox. Not a bad job just another of those things. Whole job maybe a half hour.

Remove cover, remove filter and then there is a bolt on the bottom and a bolt on the left and a nut on a stud on the left. You may be able to get enough room to pull the old hose out and thread a new one in. If not You'll have to remove the carb snorkels and pull the airbox. Not a bad job just another of those things. Whole job maybe a half hour.

If the fuel line is splitting due to age or ethanol, then the carb diaphragms and the intake hoses also deserve a thorough inspection.

If the fuel line is splitting due to age or ethanol, then the carb diaphragms and the intake hoses also deserve a thorough inspection.

Actually now, it appears the fuel lines are not leaking. I must have spilt gas on one of them, while working to free up the the carbs to get fuel flowing. They seem dry, but they are old. Never had ethanol in this bike. I know what that does to engines. I tore up two chain saws using it before a chain saw dealer said he makes a living off people that use ethanol in a 2 stroke. If that's so, it can't be good for any engine.

I would like to replace the lines because they are quite old, and I think that line that runs under the air box is friable due to my pulling on it over the years trying to get it out. I don't think the lines are as old as the bike, but they've been on the bike as long as I've had it, which has been about 25 years.

I'm not really clear what that line is for. It always seems dry when I take off the line junction.

Thanks for all the responses.

What a great forum.

Among other things, that crossover line allows you to run the bike with only one petcock open. Assuming good fuel flow from the tank and correct petcock function, this allows the rider to have 3 reserve opportunities until you are completely out of fuel.

If the fuel line is splitting due to age OR ethanol, then the carb diaphragms and the intake hoses also deserve a thorough inspection.

I don't think the lines are as old as the bike, but they've been on the bike as long as I've had it, which has been about 25 years.

Brother, 25 years is an eternity for any "rubber" part exposed to any type of fuel, ethanol or not. My original recommendation stands.

Hope this helps.

Thanks Wobbly: I'm sure those rubber diaphragms in the carbs are original. They're not giving me problems now, but your point is well taken. I'm going to have to fix the things most urgent first, however. Clogged carbs(fixed), seat not latching(fixed), new battery(working on), Fuel line replacement(working on). I need to find a DIY on replacing the diaphragms. I think I saw one recently in my travels through the internet.

I really appreciate everyone's help. This is a great forum.

I need to find a DIY on replacing the diaphragms. I really appreciate everyone's help. This is a great forum.

That's easy. About 10 minutes per side...
Disassemble one side at a time to keep from mixing parts. This work can be done with carbs on the bike, but the manifold clamps may need to be loosened to allow the carb to rotate over 15 degrees and expose the cable attachments. Take a digital photo of the throttle and choke cable adjustments to aid reassembly. Unscrew the throttle and choke cable outer housings from the top of the carb.

Remove the Phillips head screws from the top of the carb, and lift the domed diaphragm cap straight up and off. Remove the spring. Lift the diaphragm away from the carb body all the way around. Lift out the slide, which is now simply sitting inside the carb body.

Observe the external lip of the diaphragm and you'll notice a "button" of rubber at one position around the periphery of the diaphragm. That "button" seats into a notch on the body, and insures the slide is not installed backwards. Use a Sharpie felt-tipped ink pen to mark the side of the slide closest to the button. Now remove the 4 straight-slot screws inside the slide. Peel off the old diaphragm and install the new one with the new diaphragm button in the same position as the old.

Set the slide back into the carb body with the diaphragm button in its notch. If the diaphragm won't stay in place, use a small dab of grease to help it stay precisely in its groove. It only fits one way, and it's an exact fit. Replace the spring. Slide the carb's domed cover back onto the top of the carb. Make sure the 2 cable attach points are toward the engine, and re-install the Phillips head screws.

Note that the pieces only assemble one way. The marks from the Sharpie simply add a level of insurance to the re-assembly process. Screw tightness is critical. Even tightening is far more important than cinching the screws down hard. Screw torque is light and on the order of 3-4 in-lbs.

Reattach the choke and throttle cables per your photo, and sync the carbs.

Hope this helps.

As always. Thanks Wobbly. I saw a video that said that there needs to be play in both the throttle and choke cables. I have play in all but one. What does the play do, and why is it important? I really appreciate this help.

► Play in the throttle cables lets the throttle valves seek their own setting. If the throttle cables have no free play, the idle speed adjust screw won't touch the stop and the idle won't be adjustable. Not only that, but the idle speed may change with any tension on the cables, such as rotation of the front forks.

When you are ready to balance the carbs, you'll not only adjust for equal vacuum at idle speeds (after a complete warm up), but also for equal vacuum at around 1500-2000 RPM, just off idle. Adjustment at the higher speed is done with cable adjustments and assures equal throttle opening. During that adjustment is when you make sure both cables have ~2mm free play. You will have to pull back the rubber boot on the twist grip to check this.

(You won't need to balance the carbs at higher speeds because the CV carb takes care of that.)

► Play in the choke cables is not as much a big deal, other than to assure that both chokes are ON or OFF together.

😉

Thanks again Wobbly. I've got a really silly question. Where is the vacuum port on my carburetor?