Author Topic: Carb Cleaning! (Read 7438 times)

Slayer · « **on:** April 18, 2009, 11:39:31 AM »

So this weekend I am planning on taking the carbs apart and giving them a good cleaning and soaking in simple green. I have them off the bike on my table for further disassembly. On my crappy Clymer manual it says after I remove the carbs from the mounting plate to seperate the carbs by disconnecting the individual choke rods. The choke rods are the ones going through the opening that connects to the air filter right? How do you remove those? Do I need to separate them or should I just start removing the float bowl and throttle valve? Is simple green bad on rubber?

DaytonGuy · « **Reply #1 on:** April 18, 2009, 12:15:48 PM »

You have to take the choke butterflies off of the choke rod. Those are held on by two SMALL screws. Make sure you use the rigtht size philips bit too. The screws are peened on teh end and they are difficlut to get out. Slow steady pressure should do it. I stripped a couple of mine. $:-\$

Simple green is not harmful to rubber from what I'v seen.

Slayer · « **Reply #2 on:** April 18, 2009, 12:22:38 PM »

Good lookin out man thanks

TwoTired · « **Reply #3 on:** April 18, 2009, 12:28:52 PM »

You do NOT need to separate the carbs, or mess with the carb interconnect linkage to restore full function. They gunk up where gas gets to them, and these parts are all accessible with the carb bowls removed.

If you need to polish things, then break them down.

You can dunk the entire carb bank in simple green for cleaning. But, I would still "prove" each and every carb body passageway is clear by using pressurized carb cleaner in an aerosol can (the kind that come with those small red tube for the nozzle). But, don't allow rubber to soak in this stuff. A brief encounter is ok, though.

Cheers,

Slayer · « **Reply #4 on:** April 18, 2009, 12:37:37 PM »

I was going to let it sit overnight, is that too long?

TwoTired · « **Reply #5 on:** April 18, 2009, 12:39:40 PM »

Quote from: Slayer on April 18, 2009, 12:37:37 PM

I was going to let it sit overnight, is that too long?

In Simple green?

Yeah. I'd limit to two hours. If it hasn't worked by then, it's not going to.

Cheers,

Slayer · « **Reply #6 on:** April 18, 2009, 01:47:56 PM »

Ready for the big plunge! Heres what they looked like

#1: Some weird brown flakes and powder

#2: Looks okay

#3: Not bad

#4: Pretty bad pitting. It is all chalky now that it has dried.

Gordon · « **Reply #7 on:** April 18, 2009, 02:35:15 PM »

Remove the floats/float valves and all the jets and clean/soak them separately. Not only will this allow you to make sure they all get thoroughly cleaned, but it will also really help to clean out all the passages.

BobbyR · « **Reply #8 on:** April 18, 2009, 03:53:13 PM »

Don;t forget to pull out the emulsion tubes and run some thin copper wire through them. Oh yeah clean out the accel pump, that small amount of gas guns up quick.

Slayer · « **Reply #9 on:** April 18, 2009, 04:04:45 PM »

Ok here is what I pulled out. I am not sure about what the accel pump is so I am gonna have to check that out.

750goes · « **Reply #10 on:** April 18, 2009, 04:19:06 PM »

As TT said - DON'T separate the carbs - there is no real need for it.

Keep all the carb jets and pieces in separate bags per carb (number them)

then go to town with your preferred cleaning liquid - you might like to get a small toothbrush and clean those carb bodies - they have been sitting for a while by the looks of them.

The emulsion tubes need a good clean - bit of steel wool to polish them up, and clean ALL the fine holes in them as well.
Also use a cotton bud (q tip) to give the needle/seat a good polish as well - use some thinners on the q-tip and twist left/right a few times - if it comes out dirty - keep doing it till it is clean - this will make sure that the carbs will seal properly if your needles are not worn..

give the float pins a light polish as well..

Gordon · « **Reply #11 on:** April 18, 2009, 04:27:44 PM »

It almost always helps to say what bike is in question, and can never hurt.

I haven't spent a lot of time working on the later style carbs that have pressed in idle jets and float valve seats, so I can't help you much with that, but you should at least be able to remove and replace the idle jet. The float valve seat I can't really say. Regardless, anything that is brass is not a permanent part of the carb body, and if it can be removed for cleaning, it should be.

BobbyR · « **Reply #12 on:** April 18, 2009, 05:20:56 PM »

Quote from: Slayer on April 18, 2009, 11:39:31 AM

So this weekend I am planning on taking the carbs apart and giving them a good cleaning and soaking in simple green. I have them off the bike on my table for further disassembly. On my crappy Clymer manual it says after I remove the carbs from the mounting plate to seperate the carbs by disconnecting the individual choke rods. The choke rods are the ones going through the opening that connects to the air filter right? How do you remove those? Do I need to separate them or should I just start removing the float bowl and throttle valve? Is simple green bad on rubber?

Under the 3rd carb starting left to right in your pic.

eurban · « **Reply #13 on:** April 18, 2009, 06:39:25 PM »

I assume that you have a 77 or 78K or F? Here's a link to download the factory manual for the k8/f3.
http://www.mediafire.com/?5ttzdg9yyuz
It will be relevant to your bike even if it is a 77.
A few thoughts:
As others have said, don't separate the carb bodies unless things are really bad.
Make sure you remove the pressed in idle jets in the carb strip down
Soak all the brass/metal parts in regular carb dip
Boil the idle jets in hot water afterwords and then run a single strand of copper wire through them to clear them.
For the carb body assembly, I have found that a hot mix of water and simple green really works well. I actually put the carbs and Simple Green mix in a heatable container and bring them to a boil on my grill (I would do this outside, not on the stove, as Simple Green tends to make me cough). 30 minutes is enough
As tt said, spray carb cleaner through all the internal passages in the carb bodies
When putting things back together make sure to bench synchronize the slides
You can test the actual level of fuel in your float bowls using clear tubing on the overflow nubs while you open up the drain screws. They should all be identical and at or near the carb body to bowl seam.
Adjust your accelerator pump to spec and then visually confirm (carbs on bike, air box off) that each brass nozzle (you can see them sticking down in each of the carbs bore in the pic above) squirts fuel when you whack open the throttle

Have fun . . .

Spanner 1 · « **Reply #14 on:** April 18, 2009, 08:32:54 PM »

+1 with Eurban..you MUST pull the slow jets which are not removed in your pic ( the brass jet with the hole )..grip with pliers and twist slightly while pulling....notice it has more holes to clean on its sides, also the jet thru' it is very small..needs a E guitar string ( max!) to poke thru.....must be able to see thru it or its not clean...tap jet back in place when done..there is tons of reading about carb cleaning on this Forum..best of luck.

medic09 · « **Reply #15 on:** April 18, 2009, 08:34:18 PM »

Of course, what TT and others said is true about keeping it simple, not seperating bodies, etc.

But, I PROTEST! Getting bogged down in the complexities of disassembling these carbs to their most minute components, cleaning each individually, and then suffering the ordeal of reassembling and aligning all the parts, springs, etc. is a RITE OF PASSAGE. This can no more be forgone than that native group that has pubescent boys tie a vine to one ankle and then jump headlong off a cliff. Both are essential rites of passage, significant moments one wishes never to repeat. What's that? You think jumping headlong off a cliff with only an untested vine to save you is stupid? And unnecessarily disassembling carb banks is...

Oh, never mind.

Stick with TT, he knows what he's talking about.

GammaFlat · « **Reply #16 on:** April 18, 2009, 09:59:19 PM »

Quote from: medic09 on April 18, 2009, 08:34:18 PM

Of course, what TT and others said is true about keeping it simple, not seperating bodies, etc.

But, I PROTEST! Getting bogged down in the complexities of disassembling these carbs to their most minute components, cleaning each individually, and then suffering the ordeal of reassembling and aligning all the parts, springs, etc. is a RITE OF PASSAGE. This can no more be forgone than that native group that has pubescent boys tie a vine to one ankle and then jump headlong off a cliff. Both are essential rites of passage, significant moments one wishes never to repeat. What's that? You think jumping headlong off a cliff with only an untested vine to save you is stupid? And unnecessarily disassembling carb banks is...

Oh, never mind.

Stick with TT, he knows what he's talking about.

I'm just waiting for HondaMan to create a fuel injection unit for these ole doggies.

Slayer · « **Reply #17 on:** April 19, 2009, 06:15:21 PM »

The manual says not to remove the slow jet since it is a pressed fit. 1977 750F

BobbyR · « **Reply #18 on:** April 19, 2009, 06:24:45 PM »

Quote from: Slayer on April 19, 2009, 06:15:21 PM

The manual says not to remove the slow jet since it is a pressed fit. 1977 750F

Pay no attention to that, it was a nod to the EPA. You can gently pull them out and tap them back in. You will clean some crap out ot there I assure u.

Slayer · « **Reply #19 on:** April 19, 2009, 06:30:23 PM »

Damn how did you get them out? I am yanking pretty hard. Do I need this much force? I can give it a little more ass but I don't want to break anything

punch455 · « **Reply #20 on:** April 19, 2009, 07:13:05 PM »

I have the same carbs. Try twisting the slow jet as you're pulling it out. That worked for me. But you definitely want to get them out and clean the SH*T out of them. The entire idle circuit depends on them being pristine. Also, make sure the accelerator pump circuit is clean. You can check it by filling the #2 float bowl with diluted simple green and re-attaching it to the carb body. Then, push down on the pump rod. If the accelerator circuit is working, you should see the simple green squirting out of the little brass squirters near the choke plate of each carb inlet. I didn't check this circuit and ended up pulling the damn things a second and third time. Good luck man!

Spanner 1 · « **Reply #21 on:** April 19, 2009, 08:00:52 PM »

+1 with Punch...grip with pliers, twist and pull..they will come out...or leave them alone and take your carbs off again ! ( that wasn't meant to sound mean, but read the carb clean threads !! ), then look into the carb throats from air-box side...see the two tube-ends?, squirt them thru' with carb cleaner.....please read carb clean posts for more...or take your carbs off again x 2, 3 ,4 , 5....!!!

Slayer · « **Reply #22 on:** April 20, 2009, 06:38:12 PM »

Still researching and cleaning. What is the emulsion tube? Is it the jet needle holder?

Spanner 1 · « **Reply #23 on:** April 20, 2009, 09:02:45 PM »

When you unscrew the main jet assembly (8mm wrench ) the jet is the removable piece (slot for straight-edge ) which has it's size , i.e. 105 or whatever stamped on it's face or side...might need a magnifier..no, wait your 27.. you will see it !!, the tube with the holes in the sides is the 'emulsion' tube, which needs to be ' pristine' clean before you re-install it !! The needle attached to the slide spends it's life exploring the inside of this tube and allowing varying amounts of fuel to occupy the interior of the tube via it's taper, the skinnier end of the needle present when the operator opens-up the throttle and lifts the slide allowing more fuel volume in 'the tube' to be sucked into the cylinder inferno..the small holes 'round the tube allow the fuel and the air , supplied by it's very own wee tube from the carb mouth, to 'emulsify' ( kinda makes it froth ) before exiting the main jet, metered by the needle at the carb body and hence sucked into the cylinder ( the vacuum actually makes all this happen ).

Slayer · « **Reply #24 on:** April 21, 2009, 09:50:06 AM »

Ok that's what I thought it was. Just double checking. So far so good, I got the slow jets out finally. I just gave it hell and twisted and pulled after letting it soak for a little while. The accelerator pump was pretty nasty. I think that could be one contributor to the lack of fuel to the cylinder. Whatever the problem is, it is effecting all four carbs. After I get everything out and cleaned I will snap a few pictures. I found three little springs and washers that I matched up with a drawing as the pilot screw springs and washers. I don't know how those got by me but I am missing one

Yea I can see this going much faster with experience. I hope you are happy medic. Its funny when I think of the rite of passage for my Triumph was removing the baffles from the pea shooters. I think this will be more beneficial.

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Author Topic: Carb Cleaning! (Read 7438 times)