Topic: 350F Carb fiddlin'

[The Mayor]

Morning all.

So I'm somewhere in the middle of either winter maintenance or a cosmetic rebuild of my 350F... my budget has yet to decide.

I pulled off the carbs for the first time last night (this is my first dealings with a CB carb).
Got all the bodies separated, and most everything pulled out down to the emulsion tubes.
All in all I have to say everything looks great. Pretty clean and no broken parts. I was hoping but it's good to know.

My question is this...

It seems this 'yamaha carb cleaner' is extinct nowadays, and from the looks of things, I don't really feel like I need to do a terribly harsh chemical clean/dip.
What is the best cosmetic cleaning solution for my carbs, and are there some other parts deep inside I need to worry about eroding?

I've yet to find a cheap set of seals for the carbs, but would gladly replace everything if I could. Otherwise, I'd just like to get them pretty and leave well enough alone.

If anyone has a detailed diagram for the 350 carbs, I'd love to see it - seems mine is pretty low res and hard to read.

[faux fiddy]

search soda blasting

[The Mayor]

Good deal. Actually just bought a blast cabinet recently, so I'll see if I can do the soda in there.
Simple Green to degrease beforehand? Noticed my Purple Power said to be careful with aluminum....

And the more I search, the more it seems like a rebuild kit (jets & needles included) is just as much $$$ as a gasket kit? Any thoughts on these, 350/400 guys?

[flybox1]

Ello Guvnah! ...i mean Mayor 
if you let carb cleaner soak a bit on the bowls, it'll soften the clear and then you can 0000 steel wool it off and still have a shiney surface. (if you do, rinse them really well.  we dont want steel wool bits floating aroung in your bowls. 
carb cleaner and simple green are all you really need.
stay away from keyster carb kits. 
they're cheap, the needle tapers are slightly off, the jets are too.  buy OEM if you have to, but i'm sure your originals will clean up just fine.
clean all tiny holes in the emulsion tubes and jets.
be sure their orings are good and tight. 
set your floats to 24mms, and you should be good to go.

[The Mayor]

Thanks guys. Since I'm not in a hurry, I took the rack apart anyhow - some times it's nice just knowing what the hell is going on it there.
I got down to the carb bodies & choke plates, and after removing the first 2 plates I realized that those tiny plate screws must have lock-tite on them,
and it seems the ends were maybe spread a little to hold them in place? And then came the destruction of the felt orings/washers/whatever.

I'm guessing the felt I'll just have to replace myself - found a how-to in the Yahoo CB400F group that was pretty good.

I definitely need new bowl and top gaskets, and I'm guessing I might as well buy a kit now
If not Keyster, whats the best (cheap) kit out there? I was planning to reuse my hard parts...

I'm going to try dipping the bodies, and then soda blasting them to make 'em purty.
For those that have blasted these keihin carbs - did they corrode easily after - do you have to spray them with something?
Oh, and should I not dip the floats?

All in all they're not that bad to mess with (please don't make me regret saying that this spring).

[flybox1]

the keyster kits are just fine if you are poaching only the soft parts. thats what i did.
i simple green soaked my carbs and then gave 'em a good bristle brush scrubbing before re-assembly.

[bollingball]

I know it cost more but I allways buy Honda kits. Do it once and be done with it

[Deltarider]

set your floats to 24mms, and you should be good to go.

Isn't it supposed to be 21mms for a 350F?

[flybox1]

If you are not real confident about the float setting value, go to the next "even" MM setting. I honestly don't ever remember any Honda having an odd number as the float height, so I suspect the 21mm figure you have might really be 22mm (or 24mm). The best way to check the end result is a little complicated, but 100% effective: install a thin banjo bolt with a 6" long piece of clear tubing onto the drain screw of the float bowl. Then install the carb and apply fuel while holding the clear tubing upright to see how high the fuel goes (make sure the bike is level for this test). When full, the fuel level should be 4mm from the carb body side of the gasket surface for all Fours.

to get the accurate 4mm below gasket surface, all my floats needed to be at 24mm's

[The Mayor]

Fly - I noticed an earlier post about this and also think I've read a different between the 350F & 400F was the size of the main jet?
My current setup is *mostly* stock... airbox, headers, etc.

I do however have a 4-2 setup, with (I think?) HD Sportster mufflers...


If I'm getting into buying a freaking kit just to do my gaskets anyhow, is there any reason to consider a jet change?

[Goofaroo]

I always clean my carb bodies in an old crock pot with green antifreeze. You can pick up a crock pot at almost any thrift store for just a few dollars, then fill it with the antifreeze, and let them soak in it overnight. I have used a 50/50 mix or just straight and it doesn't seem to matter but if you mix it use distilled water. I use some old kitchen tongs to fish them out and then take them to a sink and scrub them with dish soap using a toothbrush. A pipe cleaner will get into all of the passages. Then if you really want to make them look really nice, sprinkle some Barkeepers Friend onto the wet carb bodies and scrub them again with a toothbrush. Then blow them out with compressed air and you are good to go. If you have felts in the bores for the choke shaft they will not be damaged by this process. For the tops and the bowls, if you want to shine them up just scrub them with the Barkeepers Friend and then polish them with Never Dull. It comes in a silver can and you can get it at most auto parts stores. If you really want to be particular, you can put the jets, emulsion tubes, and needles in the palm of your hand and scrub them with the Barkeeper's Friend and they will look great.

[faux fiddy]

Good deal. Actually just bought a blast cabinet recently, so I'll see if I can do the soda in there.
Simple Green to degrease beforehand? Noticed my Purple Power said to be careful with aluminum....

And the more I search, the more it seems like a rebuild kit (jets & needles included) is just as much $$$ as a gasket kit? Any thoughts on these, 350/400 guys?

I might have an extra set of gaskets got the tops unused. PM me if you are interested.

[flybox1]

If I'm getting into buying a freaking kit just to do my gaskets anyhow, is there any reason to consider a jet change?

theres really no telling what mains you'll need for those HD cans until you do a WOT plug chop. if you can find kits with 78's or 80's its a shot in the dark chosing the right one for your setup.
FWIW - my WOT sucked and was always real lean with my 4 into 2 jardines. idle and mid range were great (per plug chop readings) so i opted to go to 78's, and luckily those were spot on(stock air box/filter), AF screws at 7/8 turn.
can u find 1/16" OD round gasket material and make some temp ones(superglue ends together) to be able to do the rest of your tuning before you dive into jetting?