Another attempt to stop carb from overflowing

[Warwick]

No, that's the carb breather stub - just put a short length of hose on that one and let it dangle free. The vacuum take off is the upright brass stub next to the choke plunger hole on the top side of the carb. It will be obvious when you look at it as the hole the stub feeds goes through the carb venturi - thus giving you the vacuum you need to make the tap flow...

So what number needles come with these kits? I'm just a bit dubious as different 3XV carbs use different needles... And of course SP carbs are different again... Be very useful if these kits are accurate, model specific kits of course, but the ad just doesn't seem very convincing to me. Let me know what turns up won't you? 

[torp]

OK this is wierd - here's the way it's connected at the moment - vacuum stub to oil tank?

So if the carb stub goes to the fuel tank, is the oil tank pipe just an open breather?

Also, I will post detailed list of what arrives in the carb overhaul kit!

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[Marty stinkwheels]

ok the top picture is the air solenoide for the top carb, that tube should go onto a brass stub on the rear right hand side of the carb.
The second picture the arrow is pointing to the brass stub for the vac tube that goes to the petrol tap.
Hope this helps

PS the lower carb also has an air solenoid, should be located by the headstock.

[Warwick]

Blimey! It will doubtless run rather better when you get everything hooked up correctly... If stuck, just keep posting the pictures and we should be able to tell you what to attach to where.

[torp]

So if I follow this correctly the yellow arrow is for the air solenoid mounted on the oil tank, the red arrow is the breather pipe.
Many thanks for all your help!

Of course I haven't removed the front carb yet  

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[Warwick]

Correctomundo...

[sfo423]

Here is a picture of everything that comes in a kit for each carb. I'll need to get my magnifier out to read most of the sizes, but I can tell you the mains are 190, 260, 270 and the pilots are 115, 125. When I get the tube and needle size I'll update the post:

[Warwick]

Thanks for posting.

Unfortunately that bowl gasket isn't going to fit 28mm 3XV carbs... And Is that the right needle valve seat for the 28mm carbs? I've never replaced one and don't really use the 28s any more so can't say for certain off the top of my head... Float needle looks right though...

I presume you mean 12.5 and 15 for the pilots, yes? Those will be useful. Be good to know what size the needle and needle jet/emulsion tubes are too though, so if you could post up the sizes when you can read them that would be great. I Think all the 28mm carbs use either 5FN117 or 5FN118 needles?

Did they ask for year and model info, or do they just list a generic '3XV' set? 

If the needle and needle jets are the right series (673) and in 3XV sizes (just P6, P8 and Q0 for the 28mm carbs I think?) then I'd say it's still quite a bargain really. Shame about the float bowl gasket (maybe they can supply the right one if you send them an old one?) and the lack of replacement air screw, but I see you do get a new air screw O ring and spring.  And a needle clip too! Those are always useful spares if you are a ham-fisted, sausage fingered oaf like me... 

[sfo423]

Thanks for posting.


Did they ask for year and model info, or do they just list a generic '3XV' set?

 Seller stated "'91-'93 3XV" as far as compatibility. Is that possible?

[Warwick]

If we ignore the SPs (which have very different carbs and components) then, yes, it might be possible. 91-93 3XV R and RS models running the 28mm carbs run slightly different oem combinations of mains, pilots, needles and needle jets according to year, but the differences are pretty minor really and could be just about covered in the kits depending what size the needles and needle jets included are  - though I note also that there's no 200 main jet, which the 92 upper carb uses as standard. And I'm not sure about the float valve seat included either as mentioned. I'd think the best thing to do would be to compare what's in the kit with what's in (or what should be in) each carb on your particular bike - a 91 R right?

If you are not really familar with the carbs it's a good idea to keep the components from each carb seperate as the components differ between front and rear cylinder carbs - as do the carbs themselves of course, so make sure you keep the bodies and bowls matched too. The main thing you need to ascertain is the sizes for the needle and needle jets as they are the only carb parts that are 3XV specific afaik - mains, pilots etc., are just generic mikuni parts and are widely available so are no problem to replace.  Not sure what the included float bowl gasket is for though? It certainly won't fit a 3XV (see the bowl pic on page 2 for quick refernce).

Intersting stuff. Let us know how you get on.

[sfo423]

If we ignore the SPs (which have very different carbs and components) then, yes, it might be possible. 91-93 3XV R and RS models running the 28mm carbs run slightly different oem combinations of mains, pilots, needles and needle jets according to year, but the differences are pretty minor really and could be just about covered in the kits depending what size the needles and needle jets included are  - though I note also that there's no 200 main jet, which the 92 upper carb uses as standard. And I'm not sure about the float valve seat included either as mentioned. I'd think the best thing to do would be to compare what's in the kit with what's in (or what should be in) each carb on your particular bike - a 91 R right?

If you are not really familar with the carbs it's a good idea to keep the components from each carb seperate as the components differ between front and rear cylinder carbs - as do the carbs themselves of course, so make sure you keep the bodies and bowls matched too. The main thing you need to ascertain is the sizes for the needle and needle jets as they are the only carb parts that are 3XV specific afaik - mains, pilots etc., are just generic mikuni parts and are widely available so are no problem to replace.  Not sure what the included float bowl gasket is for though? It certainly won't fit a 3XV (see the bowl pic on page 2 for quick refernce).

Intersting stuff. Let us know how you get on.

OK; if the stamping is any indication of quality, we may have a problem w/tolerances.
I can usually read oem sizes w/out a magnifier but there were a big challenge with a magnifier. Here is what I "think" I have:

Main; 190, 260, 270
Pilot; 11.5, 12.5
Emultion tube: 6735JQ-0, 6735J2-6, 6735JP-6, 6735JP-8
Needle ; 5FN118

The two sets don't seem to have the three same tubes as only one set has a P8 (unless I can't read the crappy stamps). I will email the seller for a part # list for the kit. I won't have time to work on the bike for a while so actual comparison will have to wait.

   

[torp]

Hey sfo423,

did you have to pay customs charges when you carb overhaul kit arrived?

[sfo423]

Hey sfo423,

did you have to pay customs charges when you carb overhaul kit arrived?

Nope. $35 for two kits and $5 for shipping.

[ach0]

I have been following this thread with interest
and noticed the o ring for the air screw
my 3xv does not have these o rings fitted
Is this important or does it not matter ?
ach0

[sfo423]

here is what seller sent as 3XV gaskets: