First time taking apart Carburetors (Lots of pics)

*This is under construction, as I am still taking these apart/cleaning them, so expect this to be updated frequently until completion

In this thread, someone with no mechanical experience takes apart, cleans, and re-assembles Hitachi Carbs from an '82 Xj750

I will have questions along the way, and hopefully others can learn alongside me

(It appears they are pretty clean already, as nothing has stripped or been hard to remove, but I have heard the good word at the Church of clean and will be singing the gospel over the next few weeks)



1.) From left to right: Carb 4-3-2-1 (exhast side, front of the bike)


2.)Back (airbox side) from left to right: 1-2-3-4

3.)From left to right: 2-1

4.)From left to right: 4-3

5.)Top: From left to right: 2 -1

6.) Top: From left to right: 4-3

7.)Airbox side (Back) from left to right: 1-2

8.)Airbox side (Back) from left to right: 3-4

9.)4-3

10.)2-1

11.)Sync screw between 2-1

12.)Sync spring and throttle cable holder between 3-2

13.)Sync spring between 4-3

14.)Taking the choke cable holder and carb hat off of 4

15.)All carb hats off. From top to bottom 4-3-2-1

16.)Sorry about this one (disregard the numbers): FROM LEFT TO RIGHT is 1-2

17.)From left to right: 2-1:

18.)4-3

19.)Looking at the float bowls: 1-2-3-4

20.)Carb hats and float bowls off (4-3-2-1)

21.)The inside of the float bowls

22.)Underside of the carbs

23.)Needles

24.)Drawing a diagram never hurts

25.)





26.)

 

Looking good, but why the Pump pliers/channel lock pliers??

 

Very thorough, especially the orientation of the throttle shaft closure springs and how their end tangs are oriented/aligned with the throttle shaft brackets and retaining "stubs" on the carb body........many people fail to notice that aspect during dis-assembly and then get stuck when trying to re-assemble them. Also note that on many carb sets, the springs on each carb are different from each other, even though you might be able to "shoehorn" a carb #3 spring, for instance, onto carb #1.......with Very Bad Results.

P.S. previous owner installed float bowls incorrectly.......bowls should always have their drain hole port facing towards the "outside" of the carb rack (so you can access both carb drain screws from the outside of the bike). So the two left-most carbs (#1 and #2) should have the bowls whose drain ports are angled to the left, and the two right-most carbs (#3 and #4) should have bowls with drain screws facing to the right.

 

Very nice, they do look really good.
For those who know better, why is the fuel inlet port between #3-4? On mine, admittedly a different bike (XJ700) the inlet was between 2-3, or rather it was right in the middle of the rack.

 

Maxim-X: I didn't actually use them to take anything apart. They were just laying around and I used them to keep the carb "level" for pictures

Chacal: I was so nervous to try all of this that I must have read carb posts on this site for three days beforehand. Splitting the rack was what scared me the most, and I knew taking a ton of pictures would be useful. Thanks for the tip on the carb bowls. I took the drain screws out last night with little issue. They are now completely apart and ready for cleaning.

Bigshankhank: Sorry, I cannot answer that for you.

The current condition really makes me think the PO took good care of this bike, because before I picked it up it sat outside untouched for a solid year and they look like this. Further, none of the bolts/nuts/screws were stripped.

Also, I didn't see that any of the passages were blocked, though I am curious about the one within the float bowl. I will know more tonight.

Now...to figure out if I want to use brake cleaner, carb cleaner, or boiling lemon juice to clean the insides out...

Then I need to figure out how I am going to get the exterior of the bodies nice and clean. The premise of this bike is to do everything myself so that I can acquire the tools, knowledge, and confidence to wrench on something I've always wanted. Therefore, taking these bodies somewhere to have them polished is not an option. Looking into ultrasonic cleaners at the moment...

More pics soon! I am taking this Friday night off from gallivanting around the city to get some bike work done.

 

Looking good. Imo lemon boil the bowls and soak the internals in carb cleaner (carb cleaner will eat through plastic). Source (dollar tree) a baker's muffin tin. Also source a good inexpensive air compressor (you'll need it). Those screws are called jis screws. They are not standard phillips. Flat file a phillips head screw driver to function like jis. Chacal also sells a jis set. You'll also need to file a standard flat screw driver to exactly fit the slot in the mixture screws. It'll make setting the screws after the rebuild a lot easier and more accurate. The fuel float valves/needles are different. The one with the open clip has a tendency to spin and get hung on the front of the float tang. It'll cause nightmares trying to figure out what's going on. On hitachi carbs the inlet for the fuel is usually located between #1 and #2 (other bikes may be different). Chacal sells everything you'll need for the rebuild. Hope this helps.

Gary H.

 

Or just replace ALL of the Phillips/JIS screws with Allen head screws and be done with it.

 

That ^ too.

Gary H.

 

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The fuel float valves/needles are different. The one with the open clip has a tendency to spin and get hung on the front of the float tang. It'll cause nightmares trying to figure out what's going on.
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yep, that's exactly whats happened on the 2 pictures of the floats, the needle retaining clip should lay across the float tang ,not over the end of it, when you put em' back together double check that bit
stu

 

that's the cleanest set of dirty carbs i ever seen !

 

Right!

 

We try to learn as much as we can while we're in there. Just so you know...in the pic of the float towers on the right side of the swing arm there is a bent tang. That is a "stop" to prevent the floats from dropping far enough to allow the valve/needle to fall from the seat. Make certain they're not buggered. Also the labeling is incorrect in the plan view schetch of the carb jets and throttle knob. They are labeled as if you're sitting on your bike (most left is #1). You'll be helping other new members with all of this in short time. Hope this helps.

Gary H.

@ stu: Good eye. I didn't see those clips until you mentioned them.

 

Thanks stu (and everyone else) will do. I suppose I should just buy new float needles (the needles with the neoprene tips, hanging from the float tang).

Looks like I'm going to be replacing the fuel rail o-rings, float bowl gaskets, and the throttle shaft seals. Everything else seems to be in good condition.

PS, I used a 6 to 1 lemon mixture boil. Got all of the crud off!, I'm left will a dull finish however.

 

Brosef,

Did you catch Chacal comment about float bowls being installed wrong by Previous owner.......make sure of the proper orientation on re-install....

 

Noted on the float bowls!

I went back to my first post and numbered all of the pictures.


27.)Exactly. There was no screen on any of these needle seats?


28.)

29.)

30.)

31.)

32.)

33.)

34.)

35.)

36.)

37.)

38.)

39.)

40.)

41.)

42.) Brushed bodies

43,)

44.) Clean

45.) Also brushed

 

Did you drill out the plugs over the air screws, or were they already open?
Glad you are having an easy time of it, mine weren't too bad but nowhere near as nice to start with as yours.

 

Your float seats shoud have screens on them......Chacal can supply.....if you are going to buy new floatseats/needles....... Chacal sells the metal tip needles.....I am glad I went with the metal tipped needles vs the neoprene tipped needles....less chance of getting hung up and they won't wear out as the neoprenes will.

 

Nice job of identifying carb numbers on components. Make sure the etching on the throttle shafts is burrless when you reassemble, those butterflies need to sit nice and flat.

 

Will Do, Stumplifter. Thanks

Ok folks, so last night I was going to order my new throttle shaft seals, bowl gaskets, fuel rail O-rings, and float needles/seats so that I could button these babies up and see how they run after a bench/vacuum synch.

Despite my painstakingly organized workspace, I managed to lose a piece last night

Not sure what to call it, maybe the "Synch arm" on carb 3 (See attached picture). There's a good chance I'll find it, but in the off chance that I don't...does anyone have any leads on where to get one without having to buy a whole new rack? I've been unsuccessful so far. Thanks everyone.

 

IF you are only missing the circled 'washer' piece it is no problem.
I would strongly encourage you to get the Deluxe Carb Rebuild Kit from XJ4Ever - it has replacement washers and tons of other good stuff.

If you are missing the entire shaft I bet Chacal/ Len (XJ4Ever) has one of those also.

 

Yes, we should have the bracket for that throttle shaft, just drop us a note..........

 

Found it!

 

oh!
Your throttle cable linkage arm - yea, you are going to need that!

 

Yes I will!

Update: Just waiting on a few parts from Chacal, which should be here today or tomorrow (Great customer service/Shipping).

In the meantime I put the throttle shafts and butterflys back in Carbs 1 and 4 (using blue loctite).

It seems that after doing the above, that the butterfly on carb 1 is "stuck." It takes a little convincing to open, but snaps right back shut and seems to be seated properly. I say seated properly because at the moment, no light is shining through the butterfly in the closed position.

Will this be a problem? I sort of figured that once the rack is all together and bench synced that this will be non-issue, but I just wanted to see what you all thought.

Thanks!

 

it would be better if it didn't stick but if your confident it's closed all the way around, once the idle is set it won't close all the way anyhow.
if you loosen the screws a bit and snap the throttle a few times the butterfly will find it's own happy place

 

What I did, is I waited to Loctite any screws until I had everything assembled and aligned completely. This is especially true for the butterfly screws so that once everythng is racked and you can cycle the throttle shafts a few times, they can kind of seat and move alittle more smoothly. Then, pull one, Loctite it, then do the next one and so on. This also goes for the rack alignment screws.

 

If there truly is NO light shining past the butterfly and the butterfly itself is contacting the aluminum interior of the carb throat, that might be your problem right there. In operation, the brass butterfly should not really touch the carb throat interior even at idle.

If left to completely close unrestricted, it can get wedged a little and do exactly what you described.

 

To amend what I meant, this was before i re-connected the carbs. After putting everything together and bench syncing the bike started!

I could not for the life of me attach the airbox to carb boots, however, so I started it and shut it off. But it started right up and idled for about 20 seconds! Now I just have to measure the valve shims. Bike ran fine before carb tear down but I figured it couldn't hurt to go through everything

 

i use a phillips screwdriver with the point rounded off and a stiff welding rod with a 90 bent about 1/2 inch from the end. this lets you push and poke with the driver and pull with the rod back in places where your fingers can't go.
warm up the boots with a heat gun/hair drier, and it still aint easy

 

Right angle dental pick helps to keep the edges of the air box/carb boots from folding in. Made all the difference for me.cc

 

You're talking about motorcycles, right?

 

why yes it is. But the third line is about shoveling snow in Buffalo, hay that rhymes !

 

Hay! Nice!

 

Carbs are back on properly I think. Anyway to check for carb to airbox boot leaks, and also carb to head boot leaks?

Using (currently doing this) the baby bottle method as pictured.

Synced 3 and 4 easily.
Then 1 and 2 easily.

Currently syncing 2 and 3 and man is this one giving me problems.

Anyone else run in to this?

 

you did put the caps back on the vacuum ports except the ones your using, right? just checking.
why is there no red in the connecting hose? but it looks like that hose is red in the bottles
where is the flow going from/to

 

Well I believe everything is ok. 2 and 3 seemed to be synced ok after some tweaking. I could potentially have boot leaks. I suppose. Didn't seem to be running perfectly but it did idle ok with a bit of choke.

Throttle was hanging a little and it was shooting out a little black smoke during revs. It never used to put out any smoke.

My mufflers are off if that could be an issue

 

Sorry polock that picture was taken with the motor off and while doing 1 and 2.

Yes I also had everything capped. When I was doing 2 and 3 the fluid was swinging drastically but I got it pretty damn even. As I said though, I had some black smoke.

 

Any suggestions on my methods, and why I may be blowing black smoke now, but was not before I took the carbs off?

Thanks guys.

 

"My mufflers are off if that could be an issue"

there is a direct relationship between the intake and the exhaust. they must both be complete for tuning. anything less, and you're just chasing your tail.

CN

 

they are cleaner than I thought even

 

if you need any help let me know. i am a motorcycle technician certified thru honda and bmw. my shop number is 540-899-9465 hell on wheels inc. i have had alot of experience cleaning old bike carbs and unless you have a carb tank you will not be able to get them clean as i can. you can mail them to me and i will rebuild them for $200 plus parts and shipping . my address is 33 mcwhirt loop suite 110 fredericksburg va 22406 my email is hellonwheels1984@gmail.com Also, I am a 1984 AMI graduate. I specialize in restoring old bikes here. It is a nice feeling seeing old bikes on the road. I used to work at RHODES CYCLES IN MORGAN CITY LA my boss ordered alot of the non current yamahas backed then and everyone of them had to have a carb clean and tank derusted and cleaned i.e 400 550 650 750 and 900 secas maxium,viragos and fjs . Did you make sure the starter jet was cleaned for the fuel enrichment system if not, your choke will not get any fuel. My website is www.hellonwheelsinc.com I quarantee all of my work. thanks chris ferguson

 

If you don't have restrictors in the lines, you're probably sucking some of the tranny fluid into the intake. that'll cause smoke like that. I have seen several people make various types of vacuum gauges, but still find that the Margan CarbTune works best and easiest.

As far as balancing......As you found out, you balance 3 with 4, and you balance 1 with 2. You do the SAME thing with 2 and 3, but look at it this way.....you're balancing the left half with the right half. So, its 1-2 and 3-4. It is "a balancing act", and you DO have to play games with the 1/2 and 3/4 combinations AS WELL AS the idle speed screw.

We all go through that to some degree or another, and I usually double-check things, too, so do it even more. But, as time goes on and you gain experience, you'll find it's actually pretty easy and quick.

Dave Fox

 

Thanks everyone. I realize asking about the mufflers was a silly question, so I re-synced with the mufflers and airbox.

Then I took off the airbox and put the pods on, and synced again.

All is well!

 

BrosefStalin,
I have enjoyed reading your post as i am getting ready to start a 1985 XJ700N Hitachi HSC 33 rebuild and have no mechanical experience. Your photos and diagrams rock. I just came across this as i got my gas tank off and got stuck even removing the carbs themselves. I tried removing them with an allan wrench on the front but think that is incorrect as i can't get to them.

Any lessons learned getting them off would be helpful.

I am documenting my lessons learned and saving it here: https://drive.google.com/file/d/0BxC5vLEYBMOyZHQ5OTNKTnVxajQ/view?usp=sharing
Thanks,
-Brett

 

Brett, you look awfully young to be taking on a set of carbs, but that's ok there are a lot of kind, patient and smart folk here to help you.

It is recommended that you start your own thread with questions as you move through the complete refurbish process.
Mimic what Brosef did (you don't necessarily need to post everything) but do as he did, lots of pics, sketches, etc. to remind you how it was before you took it apart.

For removal, as you speak of Allen wrench I assume you were trying to remove the carb boots on the engine side. (Note my experience is with an 81 XJ650 Maxim and may not match your situation). First loosen up the 'hose clamps' on both intake and exhaust carb boots; now loosen your air box and slide it back as far as you can, remove boots from air box to carbs, now get yourself a hammer handle (or similar piece of wood) and use that to carefully pry/ wiggle the carb rack off of the engine side boots. (You did disconnect all of your linkage and hoses first right?). Many find it easiest to straddle the bike while doing this.

Here, read through this: http://xjbikes.com/forums/threads/in-the-church-of-clean.14692/
Now start a new thread.

 

After you loosen the ring clamps, push the airbox - to - carb boots back into the airbox for additional clearance in addition to loosening the box itself and pushing that back

 

Hey everyone! It's been a while, I've been busy wrenching and riding but I hope all of my fellow XJ'ers are doing well.

I'm having some carb difficulty...but mainly just syncing issues. I went ahead and bought a 4 gauge carb sync tool to make my life easier earlier this spring, and I noticed that when synced, the bike runs like a dream, but it seems that the carbs keep losing their sync very shortly after I sync them ( a few rides) and I have to re-sync them every couple of weeks (based on what my gauges are telling me).

Any idea what could be causing this? I just went through and measured my valve clearances. which are all in spec so I'm quite stuck on this one.

I've also checked with propane for vacuum leaks and im not seeing/hearing any.

Thanks guys and gals!

 

I really like your pictures this thread might be an older thread , but your pictures are great. As for your synch issue hmm what is the highest reading out of the 4 carbs ? I know on my 750 it seems to like 5 HG best all even , your float height might be off ever so slightly perhaps causing a "hunt" in the synch. What symptoms are you having that your having to recheck it? Is it making any popping out the exhaust ? Feeling of running uneven? Wow sound like a doctor since they only "practice" medicine LOl

 

Please start your own thread.

 

This is his (BrosefStalin's) thread.

Gary H.