Where's the best place to buy a carb rebuild kit for stock carbs on a 1980 cx500 custom?
Carb rebuild kit
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Ebay.
All you want is the rubber {bowl gasket, O rings etc.}
Clean all of the brass and put it back. It is Keihin quality. The replacements are not. Ditto the float needles.
If the aircut valves need replacing it is generally better to just disable them. The Chinese replacements can be problematic. Some give a generally rich mixture which leans out on decel. The opposite to the way they are meant to work. This is because of variations in the shapes of the brass bulb and it's reach. Instead of blocking the air bleed to the idle jet on decel it is blocked normally and opened by decel vacuum. YMMV.
I've recently removed the ACVs entirely from one of my bikes for this reason. It ran over rich, chewed heaps of fuel .... and then popped on decel. Sluggish too.
All you want is the rubber {bowl gasket, O rings etc.}
Clean all of the brass and put it back. It is Keihin quality. The replacements are not. Ditto the float needles.
If the aircut valves need replacing it is generally better to just disable them. The Chinese replacements can be problematic. Some give a generally rich mixture which leans out on decel. The opposite to the way they are meant to work. This is because of variations in the shapes of the brass bulb and it's reach. Instead of blocking the air bleed to the idle jet on decel it is blocked normally and opened by decel vacuum. YMMV.
I've recently removed the ACVs entirely from one of my bikes for this reason. It ran over rich, chewed heaps of fuel .... and then popped on decel. Sluggish too.
I have to buy different jets because I removed the h box and was told jets r us is the place to go. I'm buying a carb book too that was recommended to me by someone on the forums. This is gonna be a massive headache. Between the carbs and the wiring I'm not gonna have any hair left. I don't understand carbs. They're basically magical boxes to me. I couldn't even tune a carb on a little rc car. Here goes nothing
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I'm guessing you're getting either Larry cargils or Mike Nixons carb book. Either will be a good guide but even so, if you get stuck you can always ask questions here.
Replacing primary and secondary jets is OK but don't use the emulsion tubes etc supplied in the kits as they can give running problems.
Replacing primary and secondary jets is OK but don't use the emulsion tubes etc supplied in the kits as they can give running problems.
Removing the H box doesn't usually require changing the jets. You usually only need to change them if you change to pod style air filters.
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True. No jet change should be necessary.
If a little more power is required either 78 {stock} or 80 on the primary and 115 {stock in some Cs} or 118 secondary.
Don't believe that you have to go big {90/120} you'll lose power at every throttle opening below WOT at high revs.
If a little more power is required either 78 {stock} or 80 on the primary and 115 {stock in some Cs} or 118 secondary.
Don't believe that you have to go big {90/120} you'll lose power at every throttle opening below WOT at high revs.
Yea I'm getting Larry's and I've heard not to use any metal parts from the rebuild kit. I know there's a diaphragm that needs to be replaced and the gaskets and I have a few rusty screws I need to replace that holds the throttle plate on or butterfly or whatever you call it. I'm also missing 2 screws that hold the top of the carb on. Hope I can find replacements for those.
Note that the screws that attach the throttle plates to their shafts are staked to keep them from coming out. Unless they are deeply rusted I would just clean the loose part with a wire brush and leave them. It's not like anyone will see the rust and they aren't too likely to deteriorate a lot more once you start using the bike regularly.
Is Randakks not worth the coin? Also has anyone used a kit from them since the change in ownership? I'm curious if the quality is the same. I get the popping in decel An gas guzzling also I'll check out how to remove the acv.
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I can't answer about randaks as I've never bought from them.
Regarding removing the ACV entirely it is the same as 'defeating' the ACV but in this instance the ACV is removed entirely.
You need a disc of rubber the same size as the ACV D ring to block the vacuum signal and either the outer perophery of the aftermarket ACV to act as a seal for the cover or buna cord as I used here. Post 709 onward.
www.cx500forum.com
Regarding removing the ACV entirely it is the same as 'defeating' the ACV but in this instance the ACV is removed entirely.
You need a disc of rubber the same size as the ACV D ring to block the vacuum signal and either the outer perophery of the aftermarket ACV to act as a seal for the cover or buna cord as I used here. Post 709 onward.
Random stuff from the Phreak shed.
In Australia people move in next to live music venues, small factories etc and whinge about noise to the councils. These are places that have operated for years. They're listened to. "It was here first" needs to be enshrined in law. Australia is rapidly becoming the free country where nobody...
www.cx500forum.com
I have had to replace a main jet to the 120 out of a Gl500 to get rid of a bog down at 5000 rpm on a 80 Cx with stock exhaust and airbox . Not sure if the brass parts where stock or aftermarket , so only change if you have that problem. Take pictures as you take it apart helps if you forget where things go. Cheers
I got Larry's book and an ultrasonic cleaner. I have the carbs apart and cleaned and noticed the throttle return spring is bungged up so I need a new one of those as well as the two diaphrams on the side of the carbs. I probably should of just sent them off but I'm a little short on cash because of the holidays. Has anyone ever replaced the throttle return spring? It looks like it could be a pain. It's the little wound up spring. I believe it's the throttle return. And where can I find the parts I need that are good quality?
I can't help you about the spring but those diaphragms are the air cut valves (sometimes called aircuts or air cutoff valves).
Noted Vintage Honda carb specialist Mike Nixon explains what they do and why he considers bypassing them to be good practice.
And yes, I have bypassed the ACVs on my carbs.
Noted Vintage Honda carb specialist Mike Nixon explains what they do and why he considers bypassing them to be good practice.
And yes, I have bypassed the ACVs on my carbs.
Unless I'm mistaken, the small spring keeps the chokes in sync. The throttle return is a heavy spring.
Some pics would help.
Some pics would help.
Good read. That's perfect that you can bypass them. I'm not too familiar with the carbs but I'm trying to learn. How do you bypass them? I read something about an o ring but my carbs don't have o rings anywhere that I've seen.
Here's the spring I was referring to. I'm not sure what it's called or what it does but it's boogered up.
Mike explains it in the article I linked.
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