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Discussion Starter · #1 ·
I have a 1979 (built Dec 78) there are a few issues with one of the carbs, but nothing a rebuild wont fix. just not certain that these are the original carbs. The history of this bike is unknown to me and a lot of questionable work has been done. I need to know what kits to get. so in brief, how do I identify the carbs? This is the discription of the kit I located. "HONDA CX500 K&L CARB KIT 1978 1979"
 

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What is the # stamped on the side of the carbs under the VB symbol? Is the fuel inlet in the middle or on the side of the left carb? And does it have an accelerator pump?
 

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Discussion Starter · #3 ·
The only number I could see was 25A, I dont believe it has an accelerator pump.
 

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25A SHOULD have an accelerator pump on the fuel bowl of the left carb, and also have a center fuel feed. Is the # the same on both carb bodies?
 

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OK, then the kit you need will be for a 1980 and up bike. Most of the time the internal parts can be reused with great success. The ACV valves should be changed though. How do they look?
 

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What about one that is stamped 27A AKQ? It was listed as a '79 when I bought it and I have the rebuild kit for a '79. Will this work?
 

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http://www.siriusconinc.com/



this is the site Larry recommended to me for carb parts. I got all the stuff I ordered through them; they have pics of all the stuff they sell so you can see 1 for 1 what you are getting as not all kits are the same. They have pretty knowledgable customer service too.
 

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I would check out the complete rebuild kit from Raddakk's. It is a high quality kit. I also recommend buying Larry's guide to carburetor rebuilding. Also buy an ultrasonic cleaner. It is well worth the investment.



All those things helped me to rebuild my carbs (first rebuild ever). Bike now runs smoothly and starts up everytime.



All this, of course, will help when you figure out which carbs you have.
 

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Alright, I think I've established that I don't have an accelerator pump on the bike. I've ordered Larry's book for further research. I'm now curious as to why the carb kits from different manufacturers have different part lists. For instance on siriusconinc.com,



K&L CX500 kit lists

float gasket; float needle; both main and slow jets; air screw and spring; misc packing and gaskets and "O" rings as shown



CX500 Keyster kit lists

float gasket, slide needle and needle jet, float needle, #78 and #112 main jets, air screw, spring and misc packing as shown



(the float needle looks different, but otherwise these two kits are the same). But then



Randakk's Master Kit lists

Viton O-rings:



2 - fuel (idle) mixture screw (2.8 x 1.1 mm)

2 - float bowl drain screw (4.3 x 1.3 mm)

2 - CV Slide Top Limit Plug (6.9 x 1.3 mm)

1 - Accelerator pump passage at float bowl (5.0 x 1.3 mm)*

2 - Main Fuel Transfer Tubes (5.8 x 2.0 mm)

2 - Accelerator Fuel Transfer Tubes (3.8 x 2.0 mm)*

2 - Intake Manifold (40 x 2.6 mm)...slightly thicker cross section than the OEM specified o-ring for better fit and function

* as required

2 - Float Bowl Gaskets

2 Air Cutoff Valve Overhaul Kit

1 Accelerator Pump Overhaul Kit

2 idle mixture screw washers

6 float bowl screws (4 x 16 mm)

1 mm cotter pin for accelerator pump linkage - 1 supplied (simple item, but hard to find elsewhere)

2 Viton rubber blanking plugs - cover access to idle fuel jet



which is a markedly higher number of parts, but the float needle is conspicuously missing. Is this insight into the cleaning process? Should I not need to replace the needle if cleaned properly (ultrasonic methods or otherwise)?
 

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The K&L kits have a lot of parts in them that aren't needed or won't work with these carbs. The low jets only fit the later model carbs not the earlier ones. I never use any of the re manufactured parts like the jets and slide needles. Their just not made to the exact standards as the OEM parts.

Randakk's kit is a far better kit than your going to get with the K&L brand, even though he uses K&L rubber parts in his kits. The O-rings he sells are actually what you'll need and of coarse better since they are Viton. Viton O-rings are what I use in my rebuilds too. The fuel needles, most of the time, can be reused. And they should be used if possible due to the K&L needles being too long and the rubber tips are sometimes not attached well. The 78-79 needles from them can be used due to the float being adjustable to obtain 5.5mm setting. But when I use them, I put a dab of JBweld under the rubber tips. I've seen them come loose before.

As long as the spring tip is free and goes in and out the OEM needles are what I prefer every time. Clean yours up in the sonic. If the tips are sluggish,spray carb cleaner down inside the tips to loosen any gummed up fuel.Then hold the spring tip while you spin the needle. This will ensure that the springs work freely. Add a drop of thin oil, 3in1, and force it down inside. As long as the rubber tip is smooth and free of any nicks, you should be ok with them.

Also, use the stock jets. Just make sure they are clean.
 

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"If your going to do something, "Do It Right" don't do it half a**ed"



I think that says it all.
 
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