30 years of storage later, the project begins.

[Oddjob]

Want to see what 30 years of having rats piss on your bike does to it. Well have a look. These are my bank of carbs, the right hand side feeding cylinders 3 & 4 suffered far more than the left hand side, I'd spent a lot of time and money on these carbs when I was restoring it back in the early 80s. I'd had the top covers, fuel bowls, choke linkages, throttle lifters chromed, the carbs had started out bead blasted then lacquered but later I'd painted them black instead. Most of the bolts/nuts had been replaced with stainless steel ones. 

Here's how they looked just after I'd removed them.









Most of the chrome is bubbling/lifting, the only shiny nuts/bolts are the stainless ones, the rubber overflow pipes are brittle and hard. The carbs don't work, the throttles are stuck in place, you can move them but they really don't want to move and don't return when you do get some movement. I initially thought it was the connecting rod, it looked really corroded and I suspected it had bonded inside the carb plate, this is what rat piss does lads



The corrosion is so bad that I knew I needed to replace that plate, not cheap but managed to find a NOS one for £62 which is a real bargain as CMS in Holland wanted over £800 for the same piece. I thought I'd drained the carbs when I stored the bike but I remembered I'd dug it out of the shed one day and fancied a ride up the street on it, popped a battery on it, dropped some fuel in the carbs and ran it down the street minus the tank, seat and all the exhausts, it was loud that all I'll say about it. I must have forgotten to re-drain the bowls as when I popped off a fuel bowl here's what I found. I've bought some new Viton O-Rings as new petrol doesn't like the old O-Rings, it's the Ethanol in new petrol, causes them to swell.Also got some Nitrile rubber piping, same story as the o-rings, it's more resistant to Ethanol. All the chrome parts removed will be either stripped of chrome or re-chromed if they are metal, you can't find anyone chroming alloy anymore. Not yet decided what I'll be doing with the carb top and bowls, not going down the polished route as I think that's been done to death, we'll see what I can think of. 



That's a sticky mess, like tar and it had coated all the jets, this was why the throttles didn't want to open, it was like dragging a body through the mud, damned hard work. So I had to remove all this and conventional wisdom was to use an Ultrasonic bath, trouble is they cost and it's a one off cost as your unlikely to get a great deal of use out of it after so rather than do that I decided to try soaking the bowls in carb cleaner and see how it came out. Initial results looked promising, the cleaner just melts the tar, stinks like hell and gives you a headache in confined spaces but it was working so I decided to make a bath to soak the carb body in, took 3 cans of carb cleaner to fill it high enough to cover the body. Trouble was it also melted all the black paint, no bad thing as I wanted a different look so I dismantled one carb completely and soaked it for a few hours.
Carb bowl came up ok.



The jets however were another story, all were blocked solid with tar, the solvent softened it enough for me to use some interdental brushes to clean them out, used a 0.4mm, 0.5mm 0.6mm and a 0.8mm brushes and they were made for this, absolutely great results. All jets are now perfect again. 

So now I needed to clean up the body of the carb, took me a hour or so and this is how it looked after.





So everything was going ok but little did I know the god was laughing, I decided to spray the carbs a different colour, so prepped the surface with some brake cleaner and sprayed it up, gave it 2 coats then a coat of lacquer. I decided to try and harden the lacquer so it was more resistant to petrol so I used a small removable section of the carb plate and sprayed that up so I could test it in the oven. Came out ok, lacquer really hard, so in went the newly painted carb body, 150c for 40 mins, I'd meant to give it 30 mins but was busy doing the next body and forgot the time. Went to the oven and it was a HUGE mess, all the paint was bubbling, totally ruined it. Body was fine so when it had cooled down I dropped it into the solvent bath and bugger me if the paint didn't just dissolve, good job I suppose as petrol falling or spilling onto it would probably have had the same result. So that's where it stands, 2 of the carb bodies are now sprayed but not lacquered until my new petrol resistant lacquer arrives.

Will post some pics of the carbs when they are painted.

[UK Pete]

Omg, I would look for another set rather than tackle that


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[AshimotoK0]

Omg, I would look for another set rather than tackle that


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Casting look good inside though Pete ..no nasty water damage and part that main jets fit into look good I reckon. I have seen three sets of 500 carbs that looked pristine on the outside but old fuel and water ingress have rendered the bodies to be almost scrap.

[Oddjob]

I've got them all apart now and except for a sheared screw in number 3 carb the bodies are in remarkably good condition. The bowls are perfect on the inside, not so much on the outside with the chrome bubbling but I'll have them stripped soon. I'm really enjoying doing the carbs, takes me back some years 

[Trigger]

That is the worst bar I have ever seen Ken.

Looks like everyone is doing carbs at the moment. I have just finished a one set have another set to build and just stripped a 500 set. Yours should look like these soon 

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[Trigger]

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[Oddjob]

Soon? Mine look like that now except I've kept the internals separate so they go back in the same carbs, it didn't leak before so it shouldn't leak after I hope. Can't see the fuel T pieces Graham. Also I kept all my existing jets, I prefer them to a Keyster set, mine are in perfect condition so why change them.

I thought you'd have the choke linkages chromed but you've had a trip to the BZP platers again haven't you?

I did consider polishing the carbs BTH they don't last well after, the end ones are ok but the middle ones just tarnish after a while as you can't reach them without removing and dismantling them and who wants to do that. Same applies to the bowls and caps although they are easier to keep clean and shiny but still a pain.

I'm going down  a different route, we'll see how it turns out, I'm not one for the OE look, I prefer mine to reflect my taste and what I think works, like the back light will be off an RD400 as it has dual bulbs and I found just the one bulb a pain as when it blew it left you with no back light. Or I may do an LED conversion on a genuine 500 back light and see how that looks, by LED conversion I mean not just an LED bulb but a full plate with around 30 LEDs in it, it was a hobby a few years ago and I've still got thousands of LEDs lying around.

[Trigger]

The fuel T's are on the black mate just below the tops 

When you got the new plate, did it come with the alloy arms x 2 ?  The set I have just taken apart had one of the top arms broke and am looking for another.

[Oddjob]

Yeah it came complete but someone had nicked the 2 screws, one for idle and one throttle stop, DS replaced them both.

I have the arms off the old plate, I took it apart so I could store what's left, might come in useful for someone at some date, you want an arm? they are painted black but will clean it off it your interested.

I'm looking to swap a fuel bowl, got a new bank of carbs coming as I wanted some spare bowls and tops and they were dirt cheap, however there are 3 bowls for 3&4 carbs and only 1 for 1&2 due to the handing of the drain screws, I need another for 1 or 2 and I'll swap for one for 3 or 4.

Oh yeah see the fuel t's now.

[Trigger]

I have 3 x 1&2 and 1 x 3&4 ken


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[Oddjob]

Not got them yet Graham, condition from pics look excellent but of course the damage may be inside the bowl, cracked overflow pipes etc. You wanna swap a 3 & 4 for a 1& 2, seems we both get a complete set out of it.

[Oddjob]

Nothing much happening, still collecting parts just in case you were thinking the dreaded Corona virus had got me. Carbs are half done, still need some parts BZP plated, going to dismantle my spare carbs and have those parts done at the same time. Got some parts of the carbs chromed now, can't decide whether to polish the bowls and tops or spray them silver. I do have a set of tops I had chromed in the early 80s lying around, might use them or might not.

Up to now I've bought these major parts

Set of 4 into 4 exhaust new.
Genuine Seat new
Rear guard new
Speedo new
Tacho new
Handlebar switchgear new.

Ton of parts to get chromed
Ton of parts to get powder coated
Loads of parts to get BZP.
Some parts to get hard chromed.

[Bryanj]

Better plull my damn finger out on mine!!

[taysidedragon]

Considering the state the carbs were in, they've come out pretty good! 👍

[Oddjob]

You should see them now, even I'm a bit impressed. I've only sprayed and lacquered one body, the lacquer is supposed to be petrol resistant so I'm going to test that theory and see if it actually is before committing myself to doing the other 3. One of the ones left is sprayed but no lacquered awaiting results of test. The others will be sprayed this week but again not lacquered. The missus has got me decorating whilst I'm still in lockdown so the project has taken a distant back seat for a while.

Going to pop over to Sheffield to drop off some BZP parts next week, when I get those back I can rebuild the carbs entirely. I'll post some pics up when I sort out my Photobucket account.