Author Topic: Help !!! - Carb advice please  (Read 4147 times)

Offline Nurse Julie

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Help !!! - Carb advice please
« on: January 15, 2015, 05:09:53 PM »
Hi Chaps.

The only carbs I have ever taken apart before are the old Amal ones on my Triumphs and a Trident a life time ago. I am a 'Newbie' when it comes to 400/4 carbs. I need some advice to start please. I think my aim is to get the carbs stripped of the small bits etc so I can put the whole assembly in the dishwasher.I have got the carbs off bike, float bowl, leaf spring, main jet,slow jet,clip plate and valve seat out. If I now start taking it apart from the top end, will I be able to get all the bits out without separating the carbs?. Also. am I right in thinking that if I leave the carbs attached to the back plate, so not ending up with 4 separate carbs, I won't have to have the carbs synchronized? Or, is what I think I'm trying to do not even possible ? :( :( :(

Ta in advance for your help
Regards
Julie
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Offline Trigger

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Re: Help !!! - Carb advice please
« Reply #1 on: January 15, 2015, 05:27:52 PM »
I would not be putting carbs in the dish washer. Need to go in to a ultrasonic bath.
Get a camera and film the strip down. I do this with a engine that i am not familiar with.

Offline Nurse Julie

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Re: Help !!! - Carb advice please
« Reply #2 on: January 15, 2015, 05:30:22 PM »
OK. But will I still need to take everything out / off the carbs to put them in the cleaner?
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Offline Trigger

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Re: Help !!! - Carb advice please
« Reply #3 on: January 15, 2015, 05:34:35 PM »
OK. But will I still need to take everything out / off the carbs to put them in the cleaner?

Not really. You can leave them as a bank and just take the bottoms apart, that is the only stuff that needs a good clean ie, jets, tubes ect,ect.

Offline Nurse Julie

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Re: Help !!! - Carb advice please
« Reply #4 on: January 15, 2015, 05:42:47 PM »
Thanks Graham. Now all I need now is an ultrasonic cleaner. I don't suppose an industrial steralizing autoclave in the Operating Theatre would do the job?, may have to sneak my carbs in with the operating instruments when no one is looking ;D ;D ;D
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Offline Trigger

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Re: Help !!! - Carb advice please
« Reply #5 on: January 15, 2015, 05:46:19 PM »
Thanks Graham. Now all I need now is an ultrasonic cleaner. I don't suppose an industrial steralizing autoclave in the Operating Theatre would do the job?, may have to sneak my carbs in with the operating instruments when no one is looking ;D ;D ;D

Be very careful on what fluid is in the bath. Had someone drop some float bowls in caustic soda once. The caustic eats the alloy so, nothing was left apart from the brass tubes.

Offline Clem2112

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Re: Help !!! - Carb advice please
« Reply #6 on: January 15, 2015, 06:09:48 PM »
I bought a small u-sonic bath at Maplins for £40 odd a while back.
Not a mega investment for a useful tool.
Big enough for one carb body at a time. Took everything off the carb bodies first.
Only used Sea Clean fluid and warm water for 20 mins and got good results.
I Blew out all the passages and holes with compressed air afterwards then dried in the oven at a very low temp.
Some of the surfaces had lost their passivated finish so looked very matt grey, other parts looked as new after their deep cleansing.

Offline martin_uk

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Re: Help !!! - Carb advice please
« Reply #7 on: January 15, 2015, 06:37:51 PM »
Its the very small passages (drillings) that tend to block up with corrosion/ fuel residue.

An ultrasonic cleaner creates a high frequency vibration that help break this down.

Make sure you look at schematic diagram so you know which channels go where and what they do.

The carbs will need syncronising to get operating in balance with each other and the idle mixture will need to be adjusted.

I use a x10 magnifier to closely examine jets and needles.

Always good to start checking jets and needles against original spec as often PO's have changed hoping to improve performance.

It is quite a tricky job, especially with 4 carbs.

Have a look at this https://www.youtube.com/watch?v=A-n2_3re7F8

Do lots of research as it should help you decide best approach
1977 CB750F1
1977 CB750f1 836
1978 CB750F1
1975 CB500K1

Triumph Street Triple 675R
Ducati 800 Icon Scrambler
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Offline martin_uk

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Re: Help !!! - Carb advice please
« Reply #8 on: January 15, 2015, 06:45:06 PM »
[urlhttps://www.youtube.com/watch?v=dD3UWtLfzX4][/url]

Didnt watch all, but the removal of float hinge pin made me shudder as I would not hit that hard, plus the bit where he used side cutters to remove pin and says make sure you dont bend and bends :)

Be very very careful with the pillars that hold these pins as very easy to break. :-[

Best advice is watch loads and see best techniques.
1977 CB750F1
1977 CB750f1 836
1978 CB750F1
1975 CB500K1

Triumph Street Triple 675R
Ducati 800 Icon Scrambler
Triumph 3TA
AJS 350 mod16
BSA BantamD1
Honda C90zz
Honda CB500X
BSA WD B40 350

Offline Nurse Julie

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Re: Help !!! - Carb advice please
« Reply #9 on: January 15, 2015, 07:00:20 PM »
Well, I did give the pins quite a tap to remove them earlier !!!!. 3 came quite loose so easy to grip and pull with pliers but the 4th needed a bit of persuasion. Sprayed with WD40 and had 2 cuppas, tapped it on the end with the flat end of a split pin and hey presto, it shot across the room. All look straight though which is handy. Will watch that Video to learn alot more than I already know, which is a nano over nothing  ;D ;D ;D
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Offline martin_uk

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Re: Help !!! - Carb advice please
« Reply #10 on: January 15, 2015, 07:37:05 PM »
I have damaged quite a few parts in my time by using too much force and learnt its better to be cautious.

Gaining experience can be expensive :-[
1977 CB750F1
1977 CB750f1 836
1978 CB750F1
1975 CB500K1

Triumph Street Triple 675R
Ducati 800 Icon Scrambler
Triumph 3TA
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BSA BantamD1
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Offline Clem2112

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Re: Help !!! - Carb advice please
« Reply #11 on: January 15, 2015, 07:53:52 PM »
Treat them like an old watch !
The alloy posts theat support the float pins are vulnerable to force !
Pins should slide out with finger pressure once clean and shiny.
After 35 or more years the alloy can get corroded inside and out.

On mine, very little was eaten away apart from the bottom of the inlet stubs where the manifold rubbers seal.
Also the bores where the main jet o rings seat can get some wear. This seal must be good to
stop fuel bypassing the main jet.
I always add a bit of fuel preserver to the tank.... The ethanol in the petrol can absorb water and may be another threat to the carbs.

Offline Nurse Julie

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Re: Help !!! - Carb advice please
« Reply #12 on: January 15, 2015, 08:09:02 PM »
I agree with you both and that I need to be more careful when tinkering with these little parts. It's just so nice to work with 'inanimate' objects instead of human beings like I do in my day job. It doesn't matter if I get it wrong with anything on the bike when I'm learning, money can rectify it. Unfortunately, or fortunately some may say, that does not apply to humans if I get it wrong !!!
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Offline Bitsa (Ralph Wright - RIP)

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Re: Help !!! - Carb advice please
« Reply #13 on: January 15, 2015, 08:36:35 PM »
I have said this time after time the operation of 400,500 and 550 is NOT SIMPLE,all of YOU have DONE IT B4 great how many have you screwed up and got more?, Dont lie the first set I tried bollocksem?Big time?I get a bit fracked off when all say there dead easy come clean.If all the linkage works fine dont fix it if it works well by all means clean the shit out airways bowels jets etc
But there you go have I upset all you all again?
Cheers
Bitsa
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Offline hairygit

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Re: Help !!! - Carb advice please
« Reply #14 on: January 15, 2015, 08:41:07 PM »
I agree with you both and that I need to be more careful when tinkering with these little parts. It's just so nice to work with 'inanimate' objects instead of human beings like I do in my day job. It doesn't matter if I get it wrong with anything on the bike when I'm learning, money can rectify it. Unfortunately, or fortunately some may say, that does not apply to humans if I get it wrong !!!
  I'm glad about that having suffered appallingly (and still am!) at the arrogance and fu*k ups made by a Consultant surgeon 2 years ago, as a result I still can't ride my 750F1 >:( :(, only physically capable of riding my chicken chaser :)
If it's got tits or wheels, it's hassle, if it's got both, RUN!!!

 

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