I suspect Ken is right about the quality of Gerben work look at my 500 carbs!

[McCabe-Thiele (Ted)]

Today I had a look at my 500 carbs that Bryan had sent to Gerben a while back. I had noticed that the chrome on the main throttle shaft spindle was rusted in a few areas when I removed them from the bike - I put some pasivator on the rust & generally covered the links in WD 40 for dry storage in my heated office. I put the rusted  chrome down to outdoor storage.

So I had a look at them more closely - I noticed that the cable quadrant looked wonky. Closer inspection revealed that out of the six rivets that hold the two halves together only two look to have been peened in place. Two on one side & none on the other.

I was hoping to just check the bowls for old fuel and use them without dismantling them. Plan B again......


.500 carbs 1 by Macabe Thiele, on Flickr

.500 carbs 2 by Macabe Thiele, on Flickr

[Skoti]

Did you notice the mangled phillips screw head next to the idle adjustment knob?
Would have probably cost about 15 pence to renew.
If that was Gerben then failure to have changed that screw IMHO sows doubt on the general quality of the work done.

I see the fuel hose is not genuine Honda either, so good luck with that regarding ethanol proof.


Anyhow, I hope all goes well for you.

regards

Skoti

[Oddjob]

I wasn't saying Gerbens work was rubbish Ted, just that it's not as good as most people make out, they are so surprised at how good they look when they come back they don't look closely.

On carbs the attention should be in the details, the zinc plating isn't very good on those, I've seen butterflies really distorted and out of line with the cables, however the riveting isn't down to Gerben, if it's bad that down to Honda. Looking at the linkage bar it looks to me to have not been removed as the retaining pin doesn't look to have been drilled out BUT I could be wrong as he's done that and fitted another, I use screw in ones, if he done that he's used a plain rivet which IMO isn't a great idea. If he didn't remove the pin he's clearly just tidied up the linkage bar and not done a great job of that either. I had 3 of mine hard chromed, it's not cheap to have done these days, about £65 or so IIRC. However that does fix the problem permanently.

Looks like you need to have the cable clamp straightened and also check the butterfly isn't bent as well.

I did these for another member earlier this year. I opted for bright zinc plating with blue passivate rather than gold. Roo did the plating as my kit wasn't set up.











I even polished up the brass in the float bowls, might as well do a good job whilst you're in there 



The Honda piping isn't ethanol resistant Skoti, it might be now but the older stuff isn't. Common practice is to replace with Viton Orings inside and Nitrile fuel pipe which is ethanol resistant. Like this I used.

[McCabe-Thiele (Ted)]

The fuel pipe might have been fitted by Bryan I don't know - its marked as Gates Auto Master 32256 carb universkrat 6 mm.
As I will need to remove the shaft to sort out the rivets I might be minded to dismantle them completely anyway.
Some rusting on carb bowl screws as well where plating has failed.

I did not use the word rubish Ken - just not the quality I expected generally - carb tops & bottoms still have some shine to them.
When you say butterfly do you mean the cable quadrant section?
I've never dismantled that shaft so not sure what the retaining pin you refer to is or where to get a screw in type?

[Skoti]

I wasn't saying Gerbens work was rubbish Ted, just that it's not as good as most people make out, they are so surprised at how good they look when they come back they don't look closely.

On carbs the attention should be in the details, the zinc plating isn't very good on those, I've seen butterflies really distorted and out of line with the cables, however the riveting isn't down to Gerben, if it's bad that down to Honda. Looking at the linkage bar it looks to me to have not been removed as the retaining pin doesn't look to have been drilled out BUT I could be wrong as he's done that and fitted another, I use screw in ones, if he done that he's used a plain rivet which IMO isn't a great idea. If he didn't remove the pin he's clearly just tidied up the linkage bar and not done a great job of that either. I had 3 of mine hard chromed, it's not cheap to have done these days, about £65 or so IIRC. However that does fix the problem permanently.

Looks like you need to have the cable clamp straightened and also check the butterfly isn't bent as well.

I did these for another member earlier this year. I opted for bright zinc plating with blue passivate rather than gold. Roo did the plating as my kit wasn't set up.











I even polished up the brass in the float bowls, might as well do a good job whilst you're in there 



The Honda piping isn't ethanol resistant Skoti, it might be now but the older stuff isn't. Common practice is to replace with Viton Orings inside and Nitrile fuel pipe which is ethanol resistant. Like this I used.

Your work looks top notch compared with Gerben.

Incidentally the genuine Honda fuel hose from DS also comes in the correct 5.5mm I.D. which prevents stretching onto the carb 'T' piece.

https://www.davidsilverspares.co.uk/tubes

Can't see anything about the new Honda hoses actually being ethanol proof, but last weekend I clocked 30k on my old F1 (now showing 55k in total) and the genuine Honda hoses are still fine.

My Honda lawn tractor is almost 20 years old and fitted with the same genuine hoses, that's where I got the idea from.

Previous aftermarket hoses I'd tried lasted a couple of years and then snapped like dry twigs, maybe I was unlucky.
But at 22 quid a metre the genuine stuff is not cheap.


You often get what you pay for.

Cheers

Skoti

P.S.
just noticed you use the correct 'made in Japan' green and black handled Vessel screwdrivers, no mangled screw heads with your work!






 

[Bryanj]

Those carbs were exactly as i recieved them from Gerben including hose, i must admit to not being impressed with the hose but having paid a lot i fitted as is.
Now have my own ultrasonic in partnership with my mate and only worry aboutairway/jetway clealiness as i dont do restore but rebuild for use

[Oddjob]

The pipe I used is also 5.5mm ID Skoti, I like the fact it needs to stretch over the T pieces etc as you know it's secure that way. Nothing worse than blowing one off when the engines running. It went on very easily I may add, no real force needed. I used clips because the pipes were lubed with silicon oil to allow them to go on easily and fully.

The fuel pipe clip I made out of some old alloy sheet and then shrink wrapped with some heavy duty pre glued shrink wrap so it didn't cut the pipe.

A lot of the bolts and screws are stainless, the others are brand new JIS screws. I tend not to re-use screws unless they are unique.

[McCabe-Thiele (Ted)]

My Ultrasound Unit is still working (touch wood) so no problem for me to re-clean everything Bryan.

The main throttle shaft dismantling will be new territory for me  so I will take  loads of photos so that the centre spring fits back on as it should.

I am not much good at riveting except with pop rivets so more learning ahead for me.

[Oddjob]

Not sure how you are going to repair that linkage bar Ted, Graham reckons they are hard chromed but hard chrome doesn't flake like that. I suspect satin chrome, like decorative but not as bright.

Inside the 2 towers that support the linkage bar are some bronze or brass bushes, make sure they are ok. Re-assemble with some silicon oil or grease and when re-inserting the rivet or screw used to stop the bar coming out make sure the bar can spin freely, easy to nip it up and make the mechanism bind. I did consider drilling a couple of small holes in the top of the towers so I could periodically drop some oil down into the bushes but decided against it, might do it on my own set though, just cap them off with some screws etc to stop dirt gaining access. I'm not 100% sure but I suspect the butterfly on yours is twisted, once the carbs are off check it before removing to see. A quick spin should show if it's buckled. I have a spare somewhere if it's junk.

The mechanism looks complicated but TBH it's pretty simple once it comes apart.

The return spring on those carbs was from DS, it proved to be too weak to return the carbs properly and we nicked an original spring off another bank and fitted that using a 5mm stainless steel split ring on the bottom pin to reduce the pull of the spring, hence why you can see the spring weight in some of the pics, I was measuring how strong the springs were in comparison. IIRC the OE spring has a 12lb pull, with a 5mm split ring used it's only 8lbs. As we get older and the wrists start to weaken that reduction could help a lot

Forgot to mention the carb bracket, the main one, has been ceramic coated in silver rather than sprayed with silver paint, it's resistant to most things so should last as long as the hard chromed rod it's fitted with. I had 3 done at the same time, one satin black, one silver and one done in a sort of chrome finish. Just wanted to see how they looked before using them. Not sure yet what colour my bracket will be. Just bought a set of CB550 069A carbs so I have another rod and bracket to restore unless I break them for spares.

[Bryanj]

Ted, i will have a look in my "spares" and see if i have a better mounting plate/shaft to swop for you, no guarantees tho'

[McCabe-Thiele (Ted)]

Thanks Bryan tbh the photo using my phone  is a bit deceptive as the asymmetrical gap between the two holes makes it look bent but when you hold them together it looks reasonably straight.

I won't really know until it's taken apart - always wondered why they were not spot welded - not as many welding  robots  back then?

[Bryanj]

Dont think they existed in the 70's

[SteveD CB500K0]

Fiat Strada advert from 1979(?) as parodied by Not the Nine O’Clock News.

“Hand built by robots - driven by Italians”




Sent from my iPhone using Tapatalk

[AshimotoK0]

I wasn't keen on the silver painted link plate and replated but knadgered JIS screws on mine.

[Oddjob]

Maybe you'd prefer this look Ash?

I've only cleaned up the right side as the ceramic coaters left a lot of the metal unburnished, I was mucking about with some new polishing tools and used this as it is quite intricate and has hard to access areas. Left it like that so I could show it to the coaters in case they want to buy some of these new tools.



As this is the reverse it's the left side that's been done.