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Discussion Starter · #1 ·
This post started as a question about my throttle return cable but got hijacked to the topic of my problem of having a high idle speed. I figured I'd start a new thread so that some one who was having idle speed problems but not stupid questions about there throttle cable might benefit. If you need the back ground of the previous conversations to understand and avoid some of the mistakes I have made then here is a link to the original thread:



[url="http://cx500forum.com/index.php?/topic/5037-throtle-cable/?quot;]Throtle Cable - stupid question[/url]
 

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Discussion Starter · #2 ·
I got home from, work today and started my bike with the choke on/closed it started and idled at abt 2k. Once warmed up it idled at 3k
(Arrggg its getting worse) I checked for air leaks twice once with WD-40 the second time with an unlit propane torch. I didn’t notice any difference in RPMs either time. Then I thought "well just what would and air leak do"? So I undid the carb balancing screw on the right intake. The RPMs dropped down from 3k to a little under 2K. Hmmm, I thought, my problem is high idle not low, an air leak drops the rpms I don’t think I have a problem with an air leak. Lets test it again; this time with the vacuum port. Removed the plug from the vacuum port (petcock is manual). Not much change there but when I hover my finger just over the port but keep it from getting sucked onto the port then I get a slight rpm drop. Now I’m convinced (could be wrong) I don’t have an air leak I must be getting to much fuel thru the carbs. I tried to remove the cables from the carb to try running like that but didn’t have the room to do it with out removing the carbs. I removed the carbs and then the cables. So just for grins I checked the throttle plates. Hey that hole is completely opened I fixed that the other day.




The bracket that’s holds my cables that the throttle shaft linkage stops on is lose and has shifted down keeping my throttle plates from closing all the way. Stupid screw that wouldn’t tighten up. A SHCS (Socket Head Cap Screw) should fix that. I was having trouble with the screw that clamped the coke cable in place also; I’ll replace that one too. While I’m at it and the carbs are out I’ll put a new head on the mixture adjusting screw also.



Now with my carbs out , the cable bracket off, and the idle adjustment screw backed way way off there is nothing keeping my throttle plates closed they are shut all the way no light at all come thru either one; the hole(s) is completely covered (Ha! That‘l get the RPMs down). All the linkages work well. When I actuate the choke and close the choke butterflies, the choke linkage actuates the throttle linkage and the throttle plates open slightly to where the holes are covered about half way. Hey that is where I set them to a few days ago when I filed that tab down and got the bike to idle at 2k. (2k happens to be where it idles with the choke on when I first start the bike).



My plan for tomorrow:



1.) Grind a good amount off that tab. (I want to make sure the idle adjusting screw is what is controlling the idle speed not that tab)



2.) Fix the fuel mixture screw. (A nice friend gave me what I needed and told me how to do it, Thank you.
)



3.) Replace both the bracket screw and choke clamp screw with SHCS. (I’ll get them tight with out stripping the heads)



4.) Reinstall the carbs, start the bike and listen to the nice purr of a good idle speed Ahhhhh!
 

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John, that sounds like a great plan for tomorrow. I'm 90% sure you have your problem solved. I would be gentle on the tab filing, I don't think you really need to do much more. I'm not sure exactly what that tab does, but you don't want to weaken something that is necessary.



Let us know the outcome tomorrow. Thats after you take a good ride on it and listen to it idle at 1100 for awhile. It will be a great feeling to know that you figured it out.
 

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Yes you did Shep, yes you did.


As you can imagine I've had the same trouble.I put a spare pair of serviced carbs on earlier this year and the Cable bracket was bent.A couple of minutes head scratching and I found the bracket/tab was letting the throttle cable travel up but then impeding the mechanism on the way back down
.



Like I said it's hard to explain but all that area has to be right even the angles that the cables are held.
 

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Discussion Starter · #7 ·
Woot Woot




The bike now idles abt 1000-1100



And it has a new orange safety inspection sticker on the forks.



I'll have it registered by this weekend.



I do still have a lot to do:



Fork seals, new throttle and choke cables, valve and chain adjustments, and a lot of cleaning. I hope the trans will last till winter.



I really do appreciate all the help you guys have given me.
 

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That's great to hear, John. I knew you could figure it out. When and if you feel comfortable, pick up Rickbert in Sweet Springs and come back down. We can whip out the fork seals and change the cables, while Rickbert is polishing. The transmission may have to wait, but if you wanted to, we can pull the engine and take the rear cover off too. Maybe just that simple finger follower I mentioned has slipped off.
 
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