Topic: 1st carb cleaning - grocery list?

[stereosilence]

I am contemplating cleaning my carbs for the first time. I know the PO put in the pods and messed with the jets and needles, but I don't know what shape they will be in as a whole.

I would like to avoid complete deconstruction so I can have the motorcycle back ridable ASAP.

What all do I need to properly clean my carbs? Rebuild kits? Aerosol carb cleaner?

[cmonSTART]

I personally favor the aerosol carb cleaner and compressed air method.  Replace all the rubber o-rings and such. 

Are you planning on keeping the pods, or going to something more stock?

[my78k]

for just a thorough cleaning and not a rebuild these would be my items:
aerosol carb cleaner and pourable liquid (to soak the jets in)
compressed air (canned or via compressor if you have it)
fine wire or guitar string to clean out the jets
wire brush
4xsmall containers to put the jets in

of course you will need your regular hand tools and a stand of some form also you will want to check and reset the float heights while you are at it.

[stereosilence]

I am planning on keeping the pods for now. Mainly I don't want to get into a huge project. I just want to get my carbs clean for a good baseline for any other work I do in the future.

I don't know any "methods" yet. Are there photo tutorials around here? Where would I get the rubber o-rings?

Soaking the jets doesn't require taking the carbs off the rack does it? Also, what do you soak them in?

[knox-cb]

Soaking the carbs doesn't necessarily require removing them from the rack, but it sure helps. The size of the carbs is the main problem. You'll have to find a container of the appropriate size to fit them and get enough carb cleaner (which can be alot if you totally submerge them). You can use Berryman's "Chem Dip" carb cleaner which is available at Autozone, Pep Boys, etc. in gallon-sized buckets.

[ekpent]

If they look close to this get the 'GOOD' stuff. Like building an engine clean them good the first time---and that does not mean you have to replace anything or spend stupid money    http://forums.sohc4.net/index.php?topic=104060.0

[stereosilence]

Can someone point me to a tutorial of the method to clean using a wire?

[my78k]

Carb tutorials are in the Tips and Tricks section (and maybe the FAQ)

Basically all the wires is for is once you pull the jets you use the wire to pass through the openings ensuring they are clear....

Dennis

[stereosilence]

The PO told me that he had the bike recently rejetted (when he put on the pod filters). I found the remains of some carb rebuild kits in the boxes of parts and stuff he gave me. So, I don't anticipate the gaskets being in bad condition or the jets being really fouled. I hope this means it will be generally clean. I'll probably make a stab at it soon and see how it goes. I really need to make it leaner and have the idle speed adjusted. Hopefully once I redo all this it will run much better just from properly doing the settings.

[Shane72]

You'll do fine.

Once you get started it goes fairly straightforward.  I just did mine this afternoon on the '72 750, took about 3 hours and used about 2 of the large carb cleaner aresol cans (Berryman's) from the parts store.

I also used an ice cream bucket with a large bottle of pine sol mixed with water as a parts cleaner bath.  The whole carb system was extremely dirty, with years of hardened, built up grime everywhere.

Anyway, the parts I needed were limited to the 8 o-rings for the 2 fuel inlet T's, and some spiffy new R-clips for holding the choke linkage assembly on the locator pins.  All the gaskets were fuel tight and reused, and the needles, jets, and seats were cleanable and serviceable.

I wanted to avoid buying "rebuild kits", not only for the expense avoidance, but also because after having done so many carbs over the years, they just don't need new parts that often.

I have UNI pods (foam type) and baffled drag pipes.  The jets inside today were 110 mains and 40 intermediates.  The air bleed screws were only about 1/4 turn out from bottomed before--I set them to about 1/2 turn out from bottomed when reinstalling.  It runs very nicely with those settings, as one data point only.

Don't be afraid of taking the whole rack apart, it's just not that big a deal, and it's the only way you can really get to everything you'll want to clean and check.

Good luck,

Shane

[stereosilence]

Thanks Shane. Your bike sounds like it is set up the exact same as mine. I have drag pipes with baffles, and uni filters. This is my first time with carbs so I'm nervous about tearing everything to pieces when I have a hard time identifying everything.

I currently have 100/38 (and the needle is labeled D26). I thought I was running rich...do you think I need to go with your 110/40 setup?

I say rich because I feel like I have to moderate the throttle to get the best acceleration (rather than wide open) and when I engine brake, there is lots of popping.

Also, my spark plugs look like this:


On another topic, do you use K&N oil filter cleaner and oil or is it best to leave those Uni's dry?

Thanks.

[mrrch]

Popping on decelleration is usually a lean symptom.

[Shane72]

It looks like from your profile that you are working with a 550, yes?

Since mine is a 750, and I've never had a 550, I hesitate to make a recommendation on jetting for your bike--even though we have similar intake and exhaust parts.  Perhaps someone with some 550 experience will be along with another point of data for you on that.  That said, if you know that is was running well at some point in the past with this combination, I wouldn't assume that the jetting needs to be changed at all as a starting point.

About the less-than-ideal acceleration and popping on closed throttle...

Your plugs don't look that bad--the center electrodes are not fouled up.  If your mixture is off, it's not too far off, by the plugs' appearance.  I would suspect that you will find something in the carburetors to tell this story

My guess is that there is some blockage, more than likely in the pilot (slow speed) jets.  They have incredibly small orifices that tend to get blocked up when sitting.  When they are fully clean and clear, the main openings that run lengthwise through the body of the pilot jets are about the size of one wire pulled from a wire brush.  You should be able to see light, and blow through them when they are clean.  Many times (two of four last weekend, in my case) one or more of them will be entirely blocked due to fuel deposits dried up.  Poor idling and less-than-ideal throttle response through low and midrange RPM's are the result.

By definition, blocked jets equal a lean condition, and my experience with popping on deceleration has usually been from a too-lean condition.

I'd clean them to within an inch of their lives first, then re-evaluate the jetting once you know they're clean.

Good luck, let us know how you get on.

Shane

[Shane72]

On another topic, do you use K&N oil filter cleaner and oil or is it best to leave those Uni's dry?

Thanks.

Oops, forgot to respond to this part...

I haven't done anything to these UNI pods yet, since they were slightly oily from the previous owner.  Well, oily and gassy from the leaky areas that are now not leaky.

I run a UNI on my KLR as well, which is similar in foam density.  Due to the dustier conditions on that bike, I oil the filter a bit.  I probably should oil the pods a bit as well, but haven't yet done so intentionally.

When oiling foam filters, I just use the old method of cleaning first, drying second, oiling third, with the oil squeezed out by hand as much as practical.  I don't buy special oil for this, just use something heavy that sticks well.

All the best,

Shane

[stereosilence]

Well, the PO told me he had recently added the pod filters and had it jetted. However, it came with 3 carb rebuild kits (minus the float bowl gaskets  ). The jets are the stock jet sizes. So, with pod filters and the stock jets, I would think you are right and it is a leanness issue. Maybe I'll just move the needles out a notch and see what happens.

[stereosilence]

On the other hand the PO was an idiot who didn't understand what he was riding. I guess idiot isn't the right word. Maybe ignoramus. He was a college kid that needed cheap transport.

The carb cleaning is going well. The insides look just fine, but the outside is crusted in gunk. Getting that off is a real PITA.

The only problem in the first carb is the emulsion tube has some corrosion. I think it looks worse than it is in the picture, but can you tell me if I need to replace it?



Also, I have the stock needle and an aftermarket needle. They are the same size and gradiated the same. The stock one has very tiny ribs all the way down it. If you scratch your nail down the shaft you can hear a sound. They are not from corrosion or degradation. Are they just a byproduct of the equipment used to machine them or is there a reason for having that?

[faux fiddy]

Emulsion tubes are hard to find outside of ebay or junkyards.

[Shane72]

The emulsion tube looks serviceable to me.

A bit of corrosion can be cleaned easily enough, the main thing is that the holes are all totally free and clear of obstructions.  This includes all through the inside length of the tube and jets.

Surface corrosion is most troublesome when it's on close-fitting surfaces that move past each other, like on the slides.  There, it can inhibit smooth movement of the affected parts--not good.

Looks like you're into it now, great job!

Shane