85 XJ700 Carb Help

Hello Internet! First post and it is due to my inexperience... I traded a vehicle for this bike and I received it slightly disassembled. The previous owner had taken the carbs and airbox out and gave me "new" carbs from eBay. So I have this box with some screws, the airbox and the carb body. By the way this is my first ever motorcycle.

I tried to put the carbs back on for hours and said F*** it, it can wait. My question is: how the heck do you put these carbs back on?! I keep hitting a part of the engine with the bottom right of the carbs and I can't get these suckers seated in the boots. I've heard if it's warmer they'll slip right in but I'm in Indiana and it's kinda cold. Also I can figure out where the clutch cable and throttle cable go but I'm not sure about the vacuum hoses. I know there's 4 for each cylinder and the line with the filter goes to the tank but what about the other hose?

I can't for the life of me get the airbox back in, either, but I have found people saying to put little air filters on the end of the carbs - which personally - I think looks much better than the big 'o box. Is this not advised?

 

First off, welcome to the forum! Lucky for you I just did the exact procedure on my '85 xj700 maxim x. To be honest I didn't really run into any problems and I put my whole rack back in with the airbox + boots all still on the bike with little clearance issues. I had to do some finagling to get them in but they went in fine. Are the carbs the guy gave you the ones that originally come with the bike? Can you tell what brand they are on the side of the carb bodies?

This is very ill-advised. Many of those far wiser than you or I on this forum will tell you it is next to impossible to keep the bike consistent when running (what I think you are referring to) pod filters. The process to maintain a good synchronization is already tough enough on me although I haven't got a clue what I'm doing, and will be next to impossible to maintain when using individual pods. If there is a short answer or a "tl:dr" to take away from this; no it is not advised.

Cheers,

Medici

 

To get the airbox back in, take the starter off.

 

Since h0u have a MaximX, y0u sh0uld have Mikuni Carbs for it. You're also missing the small grab bar at the back. I have a couple extras if you're interested---start a conversation with me.

Dave f

 

Thank you both for the insight! I'll take the starter off tomorrow and try to slip everything back in. As for the second hose (long hose on the left of the carb body) where does that guy go? Also I do not know the brand, I'll have to look tomorrow and I'll snap a picture. From what I seen online they look spot on.

 

I'm not sure what a grab bar is but I have the backrest if that's what you're referring to. If it's not necessary I'm probably not going to buy one to be completely honest. The seat and gas tank are just sitting on there for the picture.

 

Good morning from Indiana! This is the only mark I see on the carbs, Medici.

 

Just 1 o'clock of the oil cap, to the right of the serial number, is the thing I keep hitting when trying to put the carbs back in the boots. Little bastard. Any tips or tricks?

 

Those are Hitachi carbs. I'm not a expert on the 750x, but I'd bet those carbs are for the air cooled version of this bike. In your first post, it was unclear whether you have 2 sets of carbs. The correct ones would say mikuni where the ones you showed us have that little Hitachi logo.

 

I only have this one set. My bike is water cooled so must I buy the Mikuni carbs? Also it's a XJ700, not 750. Don't know if that's crucial info or not.

 

Make sure that you search for 700x as opposed to just the 700. (In my previous post, in error I referred to displacement as 750. This is the Canadian model.) The water cooled engine is a very special beast, 5 valves per cylinder, more at home in a sport bike than a cruiser. I am jealous.

 

Haha you can be jealous once it runs, but for now it's just deconstructed artwork. So will the Hitachi carbs not work for the 700X?

 

Hey, my air-cooled 82 is garage art too, not running, so I'm OK to be jealous. Yours looks better, and has more potential! Theoretically, you could run any carbs, but you'd have to experiment with jets in order to get the tune right. Easier to get the right carbs. Not cheaper, but much easier.

 

Haha well be jealous all you want then. Mine is rusty and dusty but I can't tell you how to live your life.

I've been looking on CraigsList for a parts bike but no one has one. I may get some rubber hose and make an extension to put the carbs on the manifold boots and see how that works.

 

Wrong carbs..... Those are for the airhead.

 

That is correct. In theory, you can use any carbs in the world; in practice, you'd have to be a masochist to do so.

It's also another reason why you are having such difficulties installing the carbs back into the intakes....

 

Well I finally got the airbox in place with the removal of the starter (thanks k-moe!) and have an idea on which I'd like some info.

Firstly is there any major difference in the two carb body brands? If not I'm going to grind down the rack which is preventing me from pushing the carbs in. I can visibly discern that the carbs line up with the manifold and once the bracket is shaved I'll be able to slide them in.

Secondly there are two slots in my gas tank. One obviously houses the petcock, but what about the second slot?

 

Low fuel warning sender.

Not recommended, then you'll have a messed-up set of Hitachi carbs, and will still need to acquire the proper Mikuni carbs!! The 5-valve X engines are as close to a "race-tuned" engine as you're going to find. It is a precisely tuned "system", meaning all components are optimized to work with each other. When they run right, they absolutely scream, and rival bikes with a few hundred more cc's in power and performance. Messing around with such a system is a sure way to:

a) decrease performance
b) drive yourself crazy trying to get it to run properly.

This "system precision" is why everyone tries to warn people off from removing the airbox and using individual air filters on these engines especially.

 

Well, I guess that's that.

 

Get the right parts..... take your time--- you'll end up with a bulletproof classic ride

 

Thanks. I like the bike even though it's in pieces, but I was looking for a project and I got it, lol. If it's bulletproof I reckon that's the reason I can't find any parts bikes.
No wiring issues, no leaks, slight surface rust but beautiful. I need a couple parts but it'll have to wait till I have the money. Sure beats the POS Chevy truck I traded for it haha.

I'm searching locally for the Mikunis, but if anyone on here has some and want to do a straight up trade let me know, I'd appreciate it greatly. I didn't grind down the bracket.

 

Ebay

 

Michael, Private message sent to you

 

Well, it's been a while so I figure I'll update you guys. I have started a new job and received my first "healthy" paycheck, so I have been talking to a seller on eBay about their carbs for sale. The seller has confirmed to me that these particular carbs are in fact Mikuni's.

If you guys wouldn't mind taking a look at the link and telling me if these will work, I will personally send you a picture of a hand drawn picture of your choice*. (Disclaimer: *I am the worst artist in the world, I hope you like stick figures. First come first serve. Offer valid to the first response only. No payment necessary. Offer valid today only.)

http://m.ebay.com/itm/82-Yamaha-Vir...-Carburetor-/282340929379?nav=WATCHING_ACTIVE

So if these will work I am buying them ASAP and, of course, post a pic of the end product. After the carbs I still have to find a petcock and fuel sensor and a battery, then she'll run. I hooked a battery box up to the terminals and all the lights work, engine cranks nice, good compression; so just a couple more pieces and I'll be where I want to be!

 

Well… It looks right, but I prefer to see numbers on the balls just to verify personally, I love one sellers label things wrong… But if somebody else is bidding on something it concerns me when a seller doesn't affect labeled right-as in this case. These are not from a Virago, as a virago is a V-twin

 

Well if they look right I'm gonna pull the trigger. The seller said if they're wrong I can return them so I'm not too worried. As for your reward, would you like a hand drawn, hand made, 100% authentic piece of art? If so, what would you like?

 

I'm going to question those............the choke shaft bracket is in the wrong positions, and thee is no swedged-on end bracket (and torsion spring) for the choke cable to attach to................as Dave notes, the markings on the bowls or the end of the carb body will tell the real story as to what bike they came off of.........

WHOOPS, my bad, for some reason I thought we were talking about XJ550 carbs.

A mind is a terrible thing to waste......... :-(

 

I'm not home til tonight to compare with mine,But the enricher bracket is there, and the catch on the rod shaft is there.

 

This is the only picture I have of the carbs that's not on the web. I would take more once I get them but chances are I'll probably just try to put them in before I take pics...

 

It's 700x....Here are two 700x racks---for comparison. Obviously in desperate need of rebuild.... lol

 

Aha! So I've scored! Only paid $105 so I'm happy!

 

Ok, so, got the Mik's in the mail and the butterfly valve says "130". Is that the number you're referencing, hogfiddles? (Opposite side of your pics.) If not the screws are almost stripped and very tight on the body so I'm reluctant to try and remove the bowls and caps.

There are 2 problems I'm encountering currently:
1. I can't get all 4 of the carbs into the boots on the engine side of the carbs (not the airbox boots).
2. It's raining and thundering.

I also "mocked" the fit and placed the throttle and choke cables in their respective brackets, but the throttle is barely moving, and the choke cable isn't actuating the carb body at all. Is that just a matter of taking slack out of the cables?

 

Don't worry about the number on the butterfly. No, the number I referred to is stamped on the side of each carb, usually on the in-board side and is not easily seen from the outside of carb 1 or 4. Heck, they're often not easily seen from the inside when you're looking right at them, either------

With everything that was switched around, I'm wondering if:

1. you have the wrong cable
2. You have the right cables, but they were hooked up wrong
3. You have the right cables, but they are on the wrong sides of the handlebars.....

On the other hand, you got a used rack it may very well be in desperate need of a total rebuild.

 

The cables/controls haven't been taken off the bars so I don't see that being the problem. After consideration on my part I have an idea on the cables, I'm not worried about them right now. But I could use insight on how to get these dad-gum things in the engine boots... I got the far right one in but it popped out when I tried to push the left side in.

Time to break out the lube. *Strictly kidding.

 

A thin smear of oil or Vaseline, and your best friend will be your hot air gun, or a hair dryer.

Cables....well, you asked-----

 

Oh... well I guess I'll try that. I can't wait to see the face on the cashier when I walk up with Vaseline and a blow dryer, lol.

 

I tried oil and a blowdrier but that didn't seem to work. But what I did do, and successfully, was use 2 pry bars - one on each side carefully placed - and popped those suckers right in. Ta-daa!

As far as the control cables go, I initially forgot to place them in their respective brackets giving them too much slack. Once I placed them in their brackets, most of them function as intended; except for the clutch cable.
I believe it is encountering too much friction in the black sheathing so I'm thinking of squirting some bicycle chain dry lube in there to free up some friction. Is this a no-no?

I'll mess with the bike tomorrow, but I thought I'd give a status update. I believe this "carb help" thread is just about ready for archival!

 

Michael G, good to see another X on the board. You have great people helping you above and just take your time. A few of us are going through the same processes you are on our X models so lots of info sharing of learned tricks.

As for putting the carbs on, I go with the ratchet straps. Just make sure no metal to metal contact with the head and that the strap is in a good spot on the carbs. You don't want to bend anything as you start to crank down the strap. Angle the carb bodies down a little as you apply the pressure and then work them up and in with you hands. Heading up the boots is one of the best tricks as stated above. 30 yr old boots are not too pliable anymore, so the heat helps them flex a little bit.

Good luck.

 

Thanks, Timbox. If I had a smaller ratchet strap I definitely would have tried that. I also don't know if I would still have the bike if these guys if it wasn't for this community! I probably would have given up, lol. But using everyone's suggestions and my own thought process I know she will be up and running this spring.

I'm gonna take a look at the clutch cable again today since I have the day off. There are still a couple of parts I need to have her running basically: the fuel petcock, low fuel sensor, air filter, and a battery. I think that's it!

 

What is this thing? It's on the left side of the trans.

Also what do the 2 hoses on the carbs go to? I read that one should go to the "nipple" on the #2 boot where the carbs slide in but the hose is way too big.

Edit: Disregard the hose question, I found the answer on a different post. But since the over flow hoses just drop to the ground, why is the #2 intake boot nipple uncovered? Does anything go there?

 

I believe that is the vent for the crankcase. Stock it has a hose that goes to the airbox.

 

HI;

These two tube are connected between carb 1-2 and carb 3-4 right? Fuel tee is between 2 and 3 btw..
The 2 hoses from the carbs goes to - the ground/nowhere (they are vent tubes i believe). Just stove them behind the carbs - to the ground.
The nipple on boot 2 is for the petcock - vacuum operated (so the petcock will operate/feed fuel at "ON"/"RES" position when the engine is running.
PS: have the same fantastic bike.

 

Gotchya! Petcock to small nipple, 2 hoses going to the ground, and crank breather to airbox! I bought this thing pre-disassembled so you guys rock!

As far as my clutch cable goes, is there a bracket that holds it beneath the engine? I can depress/activate the clutch but it doesn't spring back, I have to pull it out.

 

Hmm. The only clamp that exist on my bike anyway shown in the attached image (marked with red circle). And of course connected to the clutch lever at the left handlebar. (Cable routed somewhat free under the fueltank and "turned" to the clamp from the left side - all above the carb stack). But; I didn't understand really that the clutch doesn't spring back? The 4 choke plungers are spring loaded (inside the plunger) and these 4 represent a descent force to shut the clutch off.

If you move the clutch fixture (left of the clamp) to the right (activate clutch) - it should return to its position (because of the spring in the plungers).

;A
You

 

HCP21524 Aftermarket Mikuni carb rack CLUTCH CABLE ROUTING CLIP, mounts on the upper rack bracket, #3 carb outer position, on all XJ700-X and XJ750-X models. Heavy wire "shepherd's crook" shaped clip is secured by the upper rack bracket screw, and captures and properly routes the clutch cable on its way to the clutch cover area. Perfectly replaces a commonly missing or rusted original. Use 1 per carb.


This clip seem to be missing from both of the above carb sets (not uncommon).

Clutch Pressure Plate Pivot Axle Shaft and Parts:

The pivot axle shaft is what emerges from the clutch cover and to which the clutch cable is attached to and acts upon. Although the axle rarely wears out, the oil seal where the shaft emerges from the clutch cover can be a particular source of oil leakage and is most easily replaced while the cover is removed for a clutch rebuild service.

HCP3208 OEM clutch pressure plate pivot axle shaft RETURN SPRING. Fits all XJ550, 1984-85 FJ600, XJ650, XJ700, XJ750, and XJ900 models. Each:




Fuel lines:

XJ700-X water-cooled models and XJ750-X water-cooled models:

6.35mm fuel lines:

Length: when ordering fuel line for the petcock to the carb inlet section, use a minimum length of 12" on all XJ700-X and XJ750-X models

XJ700-X and XJ750-X water-cooled models with the Mikuni carbs also use two sections of 6.35mm fuel line, each about 12" long, on the fuel bowl vent lines coming off the black plastic T-fittings located in-between the #1/2 and the #3/4 carb bodies. Be aware that these vent lines run from those t-fitting to "nowhere"; that is, their other ends are merely open-vented to the atmosphere, and both hoses are routed thru a u-shaped metal clamp that is attached to the rear of the crankcase via the #36 crankcase cinching bolt (rear edge of crankcase, right side, 3rd from the right, just to the left of the battery ground cable attachment). These lines just "hang free" and point straight down (towards the ground). These hoses do not use any pinch clamps to attach to the plastic t-fittings on the carbs.

 

Apparently I messed up the "Choke" and "Clutch" terms. Not even close.. Chacal has the answer of course.

; A

 

Good afternoon from the home of corn: Indiana!

Just thought I'd do an update and pick everyone's minds about a new found problem. I have been buying parts for the past week and a half and poured muriatic acid into my gas tank to clean the rust. I have unfortunatley purchased the wrong petcock; the base is too short for my tank, but that's not a big deal.

What *is* a big deal is that my clutch isn't engaging... Pulling the hand lever actuated the L shaped lever on the trans case, but the clutch itself doesn't engage. In 1st gear she doesn't roll even when I pull the L shaped bracket to its max by hand. I'm hesitant to pull the cover off because: A) I filled her up with new 80w90 gear oil and B) I don't want to strip the stupid Allen screws. (Why Yamaha, why...)

In conjunction my handle lever still doesn't want to spring back as it should. Even after purchasing the correct engine mounted cable bracket (which was missing) and running the cable properly.

Any insight as to what I should do to troubleshoot will of course be greatly appreciated. I searched for similar posts and found one but he hasn't concluded his findings.

As always, take care and stay safe!
Mike

 

You can lean the bike on the sidestand (leaning to the left) and remove the clutch cover without losing much (if any) oil.

BUT, if you really filled the engine with 90W gear oil, all of it need to come out and be replaced with the proper engine oil. Gear oil is only for use in the rear "differential".


If the bike has not been operated in quite some time, the clutch discs may be frozen to each other. A backyard solution is to hook everything back up again and ride the bike around, put it in low gear going up a hill and give it max throttle (careful!) with the clutch hand lever pulled in.......the torque and load resistance can sometimes break frozen clutch discs apart.

But drain the gear oil out of the engine first! Or the clutch discs will be the least of your problems.......

 

Well f*kn A. I could have sworn I needed to put that oil in the trans but hey, good thing I didn't try to start it! I guess I'll try to ride it but would it be horrible to put it in gear while not using the clutch?