as a novice, I might be missing something here but I don't understand the need for dual throttle cables. I'm working on an '80 CM400 and getting familiar with carbs/throttle cables and I just don't see the need for the "push" cable. Is it there as a safety precaution -- should pull cable get stuck open you can "push" it closed?
push-pull throttle cables
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Rumor has it that Honda included them as a California-required safety measure. I run without one on my 360, but YMMV. They don’t seem to serve a required function, but some people like having them for extra security.
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Actually, it is a pull - pull cable. Pull the throttle open, pull the throttle closed. A single cable throttle depends on the carb return spring to get the engine engine back to idle speed. The pull closed cable allows for a lighter return spring (or none) on the carb. This gives a lighter throttle. If you have ever ridden any distance you will know what this means. Correct, it is a safety item. If you remove it, why not get rid of the kill switch too? Nothing like a run away bike engine to get your heart racing.
James, the limited research I've done says that Hondas around age of my bike--1980--have push-pull throttles. I'm thinking that both cables are push-pull in that when you open throttle, one cable pulls and other pushes, vice-versa when closing throttle. And after your explanation about riding at distance wondering if it's less a safety thing and more about fatigue in hand? Also, good idea about kill switch. thinking i might also go without brakes.
Found this additional info which explains dual cables fairly clearly. guess I'll keep both
the "close throttle" cable is a pull cable just like the "open throttle" cable is a pull cable.The 'close throttle" cable IS getting "pushed" when you give the bike throttle and can be subject to binding. I took the close cable off my 1993 XRL as well, and I drilled a little hole in a cylinder head fin and mounted an extra spring to help close the throttle, as a back up to the normal spring.
And the "close throttle" cable is a safety mechanism, if it is not there, the only thing you have to close the throttle is to "push" the cable that opens the throttle....if there is significant binding now that you have removed the "close throttle" cable, you might wanna be able to reach down and close the butterfly on the carb manually.
In semi-rare conditions these days, a four-stroke single can actually make enough vacuum to make a carb slide "stick" in the bore, causing a run-away condition. Hence, the DOT requires a mechanical (i.e. not a spring) method of closing the throttle. You can remove said "push" or "idle" cable relatively safely, albeit illegally if you are aware of it's consequences and the methods of dealing with those. I would simply hit the kill button if it's ever a problem.
the "close throttle" cable is a pull cable just like the "open throttle" cable is a pull cable.The 'close throttle" cable IS getting "pushed" when you give the bike throttle and can be subject to binding. I took the close cable off my 1993 XRL as well, and I drilled a little hole in a cylinder head fin and mounted an extra spring to help close the throttle, as a back up to the normal spring.
And the "close throttle" cable is a safety mechanism, if it is not there, the only thing you have to close the throttle is to "push" the cable that opens the throttle....if there is significant binding now that you have removed the "close throttle" cable, you might wanna be able to reach down and close the butterfly on the carb manually.
In semi-rare conditions these days, a four-stroke single can actually make enough vacuum to make a carb slide "stick" in the bore, causing a run-away condition. Hence, the DOT requires a mechanical (i.e. not a spring) method of closing the throttle. You can remove said "push" or "idle" cable relatively safely, albeit illegally if you are aware of it's consequences and the methods of dealing with those. I would simply hit the kill button if it's ever a problem.
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Harleys are different. Back in the day they didn't have a return spring until the feds mandated it. The purpose was to alleviate the load required to hold the throttle open. Honda cables are are stranded wire. Stranded wire is only rated in tension and does not push. They will either bind in the outer sleeve or bow where they exit the outer sleeve. There is nothing in the world like reaching down under the tank to shut off a runaway motorcycle. All of the safety features on modern motorcycles are there because people have been killed. It amazes me how quickly people are to remove these features.
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Having the extra 'push' cable makes for a nice redundancy as well when the 'pull' one snaps on the road, can just swap it over to get you home.
That is what happened to me yesterday, ie the pull cable broke, and the push cable was not there. I had to take the broken cable loose from the handlebar throttle and another biker gave me a pair of small vice grips which I clamped to the cable. I rode home, about 10 miles, pulling the cable with the vice grips for throttle. My hand is sore today from the experience, and I'm looking for new cables. Any advice on where to buy these? I've seen some on Amazon, a pair, for as little as $20 that are supposed to fit.
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Look here https://www.motionpro.com/c/black-vinyl-cables?v=864
Be sure to use your year/model. I used a 1980 CM400T
Be sure to use your year/model. I used a 1980 CM400T
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