Author Topic: CB500 1972 carb things (Read 2168 times)

emilios · « **on:** February 28, 2009, 09:41:42 AM »

Hi
i just finished my CB500 1972...carb left to fit...but some mechanic told me that carb will not work cause i shouldnt
reassembly the "rod" that hold this "butterfly thing" cable fit?
I did reassembly those to chrome "butterfly" and some other parts...do i have to worry about it now?
Did someone reassembly that rod and bike still run ok?
Please advise
Thanks

bryanj · « **Reply #1 on:** March 01, 2009, 06:29:21 AM »

Sorry but your english does not make good sense. Pictures may help

emilios · « **Reply #2 on:** March 01, 2009, 09:48:25 AM »

Sorry for my english..
i will try again...
the four carbs are tigthen to aluminium stay...on top of that stay is a rod with some parts including throttle cable stay with spring etc...i reassembly this rod to chrome some othe parts that is on...
Did someone did that and bike after that still runs?
Cause i have been told that my bike will not run after reassembly this rod???

fmctm1sw · « **Reply #3 on:** March 01, 2009, 09:58:51 AM »

Is it in this picture?

emilios · « **Reply #4 on:** March 01, 2009, 10:02:56 AM »

Yes thats exactly...
Sorry again for my english?
So...do i have problem?

fmctm1sw · « **Reply #5 on:** March 01, 2009, 10:08:38 AM »

Save that picture in paint or something and circle the part you are asking about...

CBJoe · « **Reply #6 on:** March 01, 2009, 10:08:46 AM »

Welcome to the forum. Don't worry about your english

Practice makes perfect, so you might have to try a few times.

It sounds to me like you simply separated the carbs and then reassembled, Correct?

I don't know the CB500, but I would think that if you put everything back together correctly, you shouldn't have a problem.
Hopefully someone that knows the CB500 will offer advise.

Regards, Joe

754 · « **Reply #7 on:** March 01, 2009, 10:15:09 AM »

The big piece in the pic,
Did you remove the rod from it when you chromed it? If so did you drill out the pin? That is the key to getting it apart.

I have the parts in good condition, not chrome but rod has good plating, but it is still with rod in the big piece.

Did you perhaps chrome in one piece, and now it no longer turns?

emilios · « **Reply #8 on:** March 01, 2009, 10:27:19 AM »

First explain how to attach a foto cause i dont know...
I didnot chrome the whole thing just some parts on the rod...
I removed rod(did not chrome rod) and chrome where cables grab,spring and spring holder...thats all....
When i put back together rod is turning fine...
The mechanic that told me that i shouldnt reassembly rod is Honda motorcycle mechanic....but he didnt told me why?
Im just asking if someone did the same and carb still work fine....or if someone knows better than me?
The way i see it is that its just a rod who has to turn...

754 · « **Reply #9 on:** March 01, 2009, 10:39:00 AM »

If it went back together, and turns freely then it should be oK

BUT regarding the pin, how did you get it out??, and it MUST go back in, for carbs to work properly or idle will keep changing and parts will wear.

emilios · « **Reply #10 on:** March 01, 2009, 10:46:29 AM »

What pin?

754 · « **Reply #11 on:** March 01, 2009, 10:54:37 AM »

The big piece hold the carbs and the SHAFT slides through near the top. Before it is taken apart there is a pin in this big piece that presses into the aluminum and goes into a groove in the Shaft (you cant see this when it is together)

So if you assemble without the pin,nothing prevents the assembled shaft from sliding sideways in use, which means your idle will be changing all the time.

The pin will be difficult to remove, I assume it just got drilled ot, not that hard. However to re-assemble pin must PRESS FIT back into hole to do the job.. which means making one..oversize..

emilios · « **Reply #12 on:** March 01, 2009, 11:05:04 AM »

I didnt took off any pin...but after assemble the rod is moving sideways...is that problem? cause when carb will attached
and i push rod still goes left and rigth...
So this rod shouldnt have any sideways sliding?

emilios · « **Reply #13 on:** March 01, 2009, 11:24:48 AM »

Sorry but i didnt unterstand what Shaft slides are?
Lets number things on the rod....starting from 1 to 6
The number 1 and 6 are the same and holds the mechanism that open throttle valve..
Are you talking about the little metal under 1 and 6 that fit in a groove on rod?
I hope you unterstand what i mean...sometimes its difficult without fotos and my english

754 · « **Reply #14 on:** March 01, 2009, 11:30:29 AM »

Look on the side away from the idle setting screw.

Where the rod comes throught the casting (main frame) Pointing towards the engine there is a small flat spot with a pin in it. That pin located a goove in the shaft, pin looks like brass.

I was trying to dissassemble a set of them this week, that is how I know.

Now MAYBE.. just Maybe, with pin being soft brass, they hit it (shaft) sideways breaking it off.. if that was the case, pin will still be there, which is good.. in that case remove shaft and drive pin into the hole to get it out.. if pin is not stepped then it can be reused..
If the hole is buggered by drilling it will be more work custom fitting a new pin.

The halfround keys you refer to hold the aluminum arms with the balls to the shaft.
The pin I refer to goes in a groove that goes AROUND the shaft and is HIDDEN when all is assermbled. It prevents side movement. ( I have not got it apart yet, but know that is how it works)

emilios · « **Reply #15 on:** March 01, 2009, 12:07:36 PM »

Ok...now i unterstand...
When i was removing the rod i remember to hit with hammer and i was wondering why its so difficult to come off...
but that was happening cause this pin was holding the rod to place for sideways slidings....so i must damage pin and took rod off...
I have it now with me and im looking that flat spot and the pin in..so i just have to take off rod again...take off pin and make another one to hold rod in place....
Thanks so much and sorry for not unterstanding...but i rebuilt the whole bike and i dont want to take it to mechanic at the end...i want to do it myself....
Know i see why i had idle problem and bike didnt return to idle fast...cause maybe with rod side move,cable sticking....
You ve been great help...

754 · « **Reply #16 on:** March 01, 2009, 12:26:02 PM »

There is a slight chance you could measure how much shaft sticks out of that end on another bike. The position yours the same, and try tapping it in, maybe wiggle a bit sideways , if it starts it will go in.

As long as the hole is good, it is easy to make a new 3mm pin. Not 100% sure you can drive it into the hole with shaft out, but worst case drive it in grind it off, drive in further. but if it comes out you can reuse it.
Sounds like we bot understand how it works now, I sure did not a week ago..

mutt · « **Reply #17 on:** March 01, 2009, 09:35:48 PM »

im looking at a carb rack off a 73 500 that I have to replace the two aluminum arms tht lift the carb slides. Waitin on them in the mail. Ive been following this with interest, wat I can follow. Do you mean to sy tht behind that plug like thing stock in a ....arm? of the 4 carb plate is a 3mm brass pin that needs removing to slide that shaft free of everything?

emilios · « **Reply #18 on:** March 01, 2009, 10:54:06 PM »

In picture i marked with red the place where pin is...

emilios · « **Reply #19 on:** March 01, 2009, 11:02:10 PM »

I was wondering that if i damage shaft where pin groove is....can i add spacer to places(green marks) that i show to picture so shaft does not move sideways?

mutt · « **Reply #20 on:** March 02, 2009, 07:32:30 AM »

thanks for that pic, Emilios, thats exactly what I was looking at. Tho Im at a loss as to why the thing is nesscessary. a drift pin under a plug? As you say- a couple of spacers the right size would prevent the shaft drifting left or right, or a threaded pin, a c clip, ....its a complicated piece of kit, for sure.

bryanj · « **Reply #21 on:** March 03, 2009, 08:01:13 AM »

If you use spacers try and use nylon or some other low friction material as the throttle is heavy enough without making it worse---Also you dont want it to stick a bit open

mutt · « **Reply #22 on:** March 03, 2009, 09:01:53 AM »

I cant HELP but notice the massive rat trap of springs for throttle return.....is there some inherent flaw in these carbs that wants them to get stuck open?
And I figure this locating pin we are talking about is in a blind hole- since I have to replace the two Al. arms that lift the throttles (both cracked:overtightened) how can I get this little bugger out in one piece???

emilios · « **Reply #23 on:** March 03, 2009, 10:44:07 AM »

I really dont know how to take off pin without damage something cause i hit shaft with hammer and i damaged pin...but i didnt knew that pin was there.
Anyway i finaly drill where pin locate and made thread...so i put a bolt and locknut...
It looks that working..

mutt · « **Reply #24 on:** March 03, 2009, 11:58:00 AM »

We got a saying "Great minds think alike", also known as "Fools Seldom Differ"... I havent taken this apart yet- I want to see what the coming parts look like- but I was thinking about tapping the hole & grinding the point of the bolt to match the groove.....loctite.....
so thats how you upgraded it.....

754 · « **Reply #25 on:** March 03, 2009, 08:02:34 PM »

That or buy the whole aluminum rack with shaft & arms intact.

I was pulling these parts to sell to you, but apparently you decided, that you got a better deal.. get them to fix you up...

mutt · « **Reply #26 on:** March 04, 2009, 08:03:15 AM »

Decision made by bike owner. Im just the wrench. No need to get cranky about it.
Had I the slightest clue about what was involved I would have recommended getting the entire thing, if a 500 is available. thats why I ask questions here.

754 · « **Reply #27 on:** March 04, 2009, 09:06:03 AM »

I didnt know how much was involved either & had resigned myself to the fact that I would get nothing for the parts and some of my labour covered.. IF they got sold..

Trying to help people can backfire.

No wonder some people are sitting on huge stashes of parts, and are reluctant to even look if they have the stuff..

& other people soon get in a position on here where it is hard to get people to sell you stuff.

be carefull who you help, it can screw things up for yourself, if things go wrong..

mutt · « **Reply #28 on:** March 04, 2009, 12:10:07 PM »

So- just to be clear: you got a whole rack for a 500? I understand 550's are different- carb spacing or something....if the owner cant actually get these parts- could be the guy discovered its not easy to get apart- at any rate, i dont see them- ill take what you got off your hands.
its holdin up the show here.....

bryanj · « **Reply #29 on:** March 04, 2009, 11:15:01 PM »

500/550 1972 through 1976 are the same(ish) 1977/78 are different

News:

Author Topic: CB500 1972 carb things (Read 2168 times)

mutt

mutt

mutt

mutt

mutt

mutt