Pulled the carbs today.....

I thought I would attach some pictures and you pros can tell me how things look and what will need to be done. #3 and 4 carbs failed the "plunk" test.














In this last picture, which is the right way to have the floats hanging on the tang? All of the carbs are like that on the right of this pic, but the float on the #1 isnt attached the same. Is the carb on the right the correct way?





All in all, Id say the carbs look pretty good, there wasnt any gunk in the float bowls. They are filthy on the outside at least, on the inside, it looks like they need some light cleaning. The diaphragms seem in pretty good condition.

I havent taken out the jets, is there any special procedure to know about this?

 

If you're going to do one, do them all. I followed Rick's methodology and used some 600 grit sandpaper and WD40. Take a small strip, fold a bit over at the end to give your fingertip something to grab onto, and spritz the rest. Do maybe a quarter of the bore at a time. Works wonders.

Oh, and I wouldn't store the diaphragms/pistons on their side like that.

I'm not entirely certain what you're referring to, unless you're talking about the float needle; three of them having one wire wrapped around the tang, where the last has two. If that's what caught your eye, be at ease; that part makes absolutely no difference what-so-freaking-ever.

On the other hand, that gives me the impression that the float needle in question isn't the same as the others; if it's longer than the rest, then setting the float levels can get a bit more complicated.

Not a "special procedure", per se, but remember that the main jet holds the emulsion tube in place. Also; Rick has time and again put forth some sage advice about screwdrivers.

When using a screwdriver with jets or mixture screws, make sure that the blade has NO free play whatsoever. None. Get thee to the 99 cent store, grab a couple, and spend some quality time with Mr. Grinder. (With the Mikuni carbs, it's almost a requirement.)

I've put a file online; it doesn't give a detailed dismantling of the Hitachis, but it may or may not help (I did it up when I was changing throttle shaft seals).

http://mok.fileave.com/Hitachi%20Carb%20Breakdown.pdf

You might also be wondering, "How does one set the fuel level?" Glad you asked...

http://mok.fileave.com/FUEL%20LEVEL%20draft%208c.pdf

 

Good thing the diaphragms havent been sitting too long.

Ive never done this before so Im need all advice I can get. I have been trying read up on it as much as I can. I also have the XJCD, but somethings are still a mystery to me. I will probably wetsand the diaphragms in a bit to make sure they are smooth.

That was what I was referring to. Ill let you know if it is the same or not. I can see someone has gone through these before. Luckily, so far it seems things were done pretty well. The closest thing I can see as far as damage goes is whoever went through these scratched numbers into everything. I guess it will help to keep me organized.

Im not really sure what an emulsion tube is? Will it need to be removed for cleaning? So far, I havent had any problems with screws (thankfully). I had a slight problem with one drainage screw, but I was able to get it out without damaging anything. I soaked all screws with some WD40 before I attempted any screws.


Im hoping not to have to change throttle shaft seals. With that being said, I guess dipping is out of the question? What is a good way to get everything cleaned up without harming these seals are the cosmetic look of the carbs themselves? Im thinking of soda blasting the carb bodies (not inside) to clean them up a bit, any opinions on that?


Thanks again, I will be posting pictures of my progress when available.

 

Well what do you know......




So what do I do about this? Should I get a replacement?

 

What I did before I tore into mine for the first time was run down to a wrecking yard and buy a spare set to practice on first. Not required by any means, but I thought it prudent.

It's not the diaphragm pistons that you're sanding down, it's the bore that they came out of.

You know that brass thing that the needle on the diaphragm piston goes into? That thing.

Yes. There are a series of holes in them that need to be kept open. Again, the main fuel jet is what holds it in the carb body. If it doesn't come out on its own after you remove the jet (turn the carb body upside down), then you can gently nudge it from the bottom.

From the XJCD main menu; click on "Carburetors and Fuel", and the first how-to you should see is "Cleaning the Hitachi Carbs". The pictures are a wee bit small for my taste, but every bit helps.

Pretty much. That, plus there's the teensy rubber o-ring under the mixture screw, and the rubber boot over the starter plunger. If you want to dip the bodies, you're going to have to pull every single piece. What you can dip safely without a complete disassemble are the jets, the emulsion tubes, and the float bowls.

I've never done it, so I couldn't say. Probably just wipe them down as best you can with rags and carb cleaner.

You can do this. Hell, if *I* can do it, anyone can.

Well, well, what have we here...

Probably do the entire set, if for no other reason than to make absolutely, positively sure that all four match. After all, if you get one replacement, there's no guarantee it'll be the same as the other three.

 

Oh ok, so then I am wetsanding the carb themselves where the piston slides, I got it now.

So now that I have the floats off, I take the jets off right? I take off all three things on the bottom of the carb that is almost in a linear formation?

Ill see how much Chacal wants for a set. Does anyone know the part number for these floats? I figured replacing all would be a good idea too.

 

Also, do I go ahead and pull the jets out of the top of the carbs? I think there is two if I remember right.

The main jet on my second carb wont come off, it just keeps spinning freely and wont pull of. Any ideas?

 

Got the main jet off. I wasnt aware that the main jet screwed into the emulsifier tube. Had to hold the emulsifier tube still while I unscrewed the jet.


I suppose another question I would like to ask is this; What parts CANNOT be soaked in cleaner?

 

The carb bodies if the throttle shaft seals are still in them.

Anything rubber.

Also, there is no reason to replace the floats if they are not cracked or damaged. They're solid hunks of plastic and don't really wear out.

 

I take my carbs into a local yamaha shop and use the ultrasonic cleaner they have. It uses a "detergent" rather than a volitile cleaner like carb dip or cleaner. Safe for rubber parts... Gets the carbs clean and looking almost like new. Costs about $25 for me to do it.

 

I use a scotch-brite buff to clean the slide bores. Much easier with a dremel than by hand! Use the fine grade, I don't remember the color. Do Not buff out the slides, they are coated. Soda blast away, it won't hurt the carbs and rinses off nicely (this is what I do). Ultrasonic is nice for a final clean, in my experience it doesn't get the corrosion off. Your carbs are beautiful by comparison to the set I'm working on right now. #3 on my set was rusted solid (thank Heaven for Evap-o-rust! $20 a gallon at Harbor Freight). Check those shaft seals and see if they are hard, if they even blink sideways, replace them.

 

Is it just me or do the floats look like they are on upside down. the floats should hang into the bowl not vise versa .

 

Nope, they are correct. Hope yours aren't in upside down Formula!

 

Haha, I hope I didnt raise a debate!

Fitz, do you think there will be a problem trying to adjust fuel levels with a different float needle on that carb? Is that what you are referring to?

Im going to try to clean up what I can on the outside of the carbs, and then try a soda blast. I suppose I will see what happens from there. I will get some cleaner today and let the parts soak. Can the emulsifier tube be soaked as well? On the XJCD, it says some parts are just wiped off, I would rather soak them and make sure they are clean inside and out.

Do I remove the jets on the top of the carbs as well?

 

more pictures!!! this thread is helpful because im about to do the same for the first time. keep up the good work

 

Ill take some more in just a sec, what would you like some pics of? I may do some sort of how-to do build of the XJCD a bit, those small pics are not too helpful.

 

Well I am pretty sure I stripped the pilot air jet. What should I do? Leave it in? Or get it out somehow and replace it?

 

Leave it in.

You don't have to remove the Air Jets.

If its loose. Touch the seam with LockTite.

 

Na I know mine are right side up. On further inspection of a parts break down they are correct sorry just looked weird.

 

Thanks Rick, it certainly isnt loose lol.

 

Geez formula!!! Dont scare me like that lol

Ive still yet to see anything that is a severe problem, the worst I have seen is the mismatched float needles.

I cleaned up some stuff today, Ill post an update when I get home from class and the pics are done uploading.

 

Well today, well I guess it was technically yesterday, I got tired of my hands getting filthy everyone time I touched the carb bodies, so I decided to clean them up. After using some scotch-brite, all carbs passed the "plunk" test. I have the various other parts soaking. Here are some pics, you guys tell me what you think so far.











I think I will still be soda blasting them. But at least they are degreased and pretty clean.

Anyone have anymore thoughts on the float needle situation?

 

You are going to want to pull those enrichment plungers and make sure the passages down to the brass extention tubes are clear.

MN

 

I think they are clean enough - - no need to soda blast them.
I'm doing the Seca 750 carbs at the same time,
re-building (or cleaning) the E-Bay $7.00 rack (650) with 750 jets.
trying to avoid doing the throttle shaft seals this way.

I got a guitar string to help chase thru the passages, such as the brass extension tube, it's side vent, the float bowl jet, and the Pilot circuits.

 

When I spend the time doing a thorough job of cleaning and "Clean-Tuning, ...

I mark the Enrichment Circuit Activating Rod and remove it.
T chuck it in my Drill and shine it with 400-800 & 1000.

Screw the Fork-Fingers into a wood block and hold the block in a vice to "Shoe-shine" the Fork-Fingers.

Polish the Enrichment Plungers and Mounts.

Eyeball Sync the Enrichment Fingers lifting the Plungers.
Squaring-up the Top Hats on the Plungers.
(Heat, Roll on Flat Surface or use Needle Nose.)

Performance Polish Bores:

 

'Em are right purty just the way they are, I wouldn't blast them. Polish up the bits everyon mentioned and you'll have a purring motor in short order.

 

Ok, now I am way confused lol.

What are the "enrichment plungers", "Enrichment Circuit Activating Rod", and "Enrichment Fingers". I said I was new!!! haha

 

Some folk call them-there items, ... the "Chokes"

 

Ah ok, I guessed right. How exactly do I remove the rod and plungers? Are they just held in with screws?

 

Raven,

Those enrichment plungers are connected to the 4 little forks that lift up when you pull the choke lever over. You had to take the cable off when the carbs came off of the bike.

MN

 

Ya, the whole "enrichment" term threw me off. Im ore familiar with the term "choke" though I understand it is not the correct term for it. Thanks guys!

 

Each fork has a straight slot set screw. Take the set screws out and slide the rod out. Keep track of the spacers. The plungers are held in with a 10mm nut. Do not mix them up because they are rubber tiped and they like to be where they came from when you put them back in.

MN

 

Before you delve into doing the Enrichments:

Take a Center Punch and Dot the Right end of the ROD.
Take a Picture of the Linkage ... especially the Cable Linkage Hook-up.
Mark the "Jay-Link" with Arrows. Up ... and ... Left.

Draw the Left Side so you know where the Bushings go.

Take-out the Activating Arm and Locking Set Screws
Slide the ROD out.
Collect the Parts.

Remove the Rubber Dust Caps.
Undo the Hexes.
Remove the Hex, Plunger and Spring.

Clean - Clean - Clean

Spin the Rod in a Drill -- 400 - 800 - 1000
Polish the Plungers. Brasso.
Treat the Dust Caps -- Armoral or TEAC Rubber Conditioner
Slide the ROD to the Right

 

How can I get the rubber dust caps off without damaging them? They dont seem to want to come off at all.

 

I got them off. I used a flat blade screw driver, wrapped a napkin over the tip and pulled up on it while pulling on each side with my hand. No damage.

 

Use the HANDLE of a "Butler Stimulator" as a Special Tool!

The Rubber Tip is easily removed from the Butler Handle.

Leaving the perfect Tool for Dust Covers and Master Cylinder Seals.

http://store.alleonpharmacy.net/p017178.html

 

Wow that probably would have been a lot easier to use.

After taking everything off, I see there is a screw next to where the plungers came from. Do I remove these?

 

Try using a hair dryer on rubber parts works real good on the intakes when re-installing the rack. Carbs are looking good.

 

Raven, if you are doing a complete overhaul, yes. Those screws are your air/fuel adjustment needles. They hold in their bore a spring, washer and o-ring (in that order of removal, be careful 'cause they are tiny!). You can get obstinate parts out of there with a length of 22 or 20 AWG solid core wire or similar substitute. I like the wire since it is made of copper and is fairly soft, meaning less likely to scratch the needle seat. You will need to reset and tweak your air/fuel mixture when the carbs are reinstalled but you should be able to do that easily with a colortune (you do have one, right?).

 

Im gonna have to get one. I think I may leave those alone.

 

You need to pull your Pilot jets, and related hidden parts, then clean the Pilot circuit, including running a wire thru the 3 tiny atomization holes visible near the throttle plates. This is one of the most critical areas to clean (zestfully even).

 

Which are the pilot jets exactly?

 

speaking of colortune, anyone have one they recommend? I found this cheaper one...

http://www.amazon.com/Automotive-Specia ... B0031KRXT2

any thoughts?

 

Hi Raven,
That amazon link looks like an an adapter only.
<snip>
Product Description
10mm spark plug adapter for the 14mm Colortune Engine Analyzer. 12mm, 14mm Long Reach, and 18mm also available.
</snip>

I can tell you that the colourtune plug from chacal (HCP95C $49.95USD) works a charm though.

 

Whoops, ya it would seem it is just an adapter. Im still on a budget, so I have to see what I can do.

 

Does anyone have a used one for sale?

 

I have some more pics of my progress. What I did last night pretty much.

 

You're in "The Zone"
Those babies are shining, ... for sure.

Look at the "Bands" on the Cones at the bottoms of the Plungers.

IF they need to be "Touched-up"
Put 2 Drops of Water-based Valve Lapping Compound on the Seats where those Cones fit in the Carb Body.

Mount the Plunger in the Hex Body without the Spring.
Lower the Plunger and tap on the end.
Hold the Top between your Thumb and Forefinger and "Pinch-Twist" some VERY LIGHT revolutions.

Check your progress.
When you have a "Band" with the same width all-around, ...
You're done.

 

Ok, I was confused, but after thinking about it, it sounds like you are talking about if it needs help with it seating flush in the carb body. Correct me if I am wrong please! I suppose if that is the case, a good way to check is to see if it wobbles inside the carb body?

 

No. That's not it.

The Cone fits a Seat.
Its self-centering.
You just want to be sure the Cone hasn't worn-out unevenly.

You should be able to see the shadow of wear on the Cone.