85' XJ700n Rebuild Issues

The Backstory:
I was in high school and interest in mechanics and I've always wanted a bike and I was looking around for one. I like the old school style and wanted to learn more about engines and such because I'm that type of guy (I asked for a weed-whacker for my 16th birthday). My dad and I found a 1985 XJ700n in someone's back storage unit for $300 and decided it was worth it to at least learn something. He claimed that it ran three years before and just randomly stopped due to a dead battery and he never rode it again...seems fishy enough...I worked with a mechanic friend and we got it going after getting a new battery, front tire, plugs, TCI box, and a starter. It ran even on pods after we sent the carbs to a show to get cleaned. I rode it around a couple times and then it sat for the winter and I spent a lot of time trying to get it started again with help from everyone on here. I did get it going, but it was running lean and backfiring a lot and it had an awful hanging idle after I would blip the throttle. I did a deep clean of the carbs, got the floats leveled using the clear tube method, and did a bench synch and still had the same problem. By this time it was winter and I'm in college so I didn't have enough time to really mess with it so I ended up just buying a new battery and found an OEM air filter to add to the original airbox. I just got it going again today after adding fresh gas and after a few minutes of running the black smoke turned to white smoke and now it barely smokes out the exhaust but it's still got the bad hanging idle and it's not safe to ride. If you need more info let me know, I'd like to get it running safely as soon as possible!
PS: The valves are inspect, air mixture screws are at 2.5 turns out, and someone needs to post an easy way to get the carbs on/off with the new airbox in the way, it was a beast with pods, but it took forever with the airbox taking up so much room!!!

 

This is the reason I had to replace the starter...

 

The posts above are basically the condition the bike was in when I got it, everything has since been cleaned, but I still have the hanging idle issue. Also, I had to tow it 3 hours back from my friend's shop and we didn't have a trailer so I took a piece of square pipe the fit the hitch and welded a piece of tubing through the middle of it so that I got mount the forks to it like a front tire. I put a fork on either side with the tubing in the middle and then ran the axle bolt through the fork - tubing - fork. It would angle the bike weird on super tight corners, but besides the weird stares at the gas station it was all good.

 

Wow, those are some gummed up carbs! Did you fully rebuild them, or just clean them? Did you take note of what jets you had in there?

Did you disconnect the final drive when you towed it? Looks like it was riding on the back tire?

 

Nice! I chuckled, but really enjoy the creative solution to towing.

Hanging idle.
If your valves are inspec, you should verify that there are no vacuum leaks (an unlit propane tank waved around the carbs should res veal a vac. leak), those carbs looked horrendous, hopefully they are now crispy Church clean and the rack was broken and throttle shaft seals replaced - otherwise I bet they are leaking.
If that all checks out then, beg, borrow, steal or make a manometer and vacuum synch those carbs. Out of synch carbs can cause an idle to hang.
Are you sure that the throttle cable is not hanging up?
What are the jet sizes in the carbs? Someone may have rejected for the pods.
(Edit) sorry for the redundancy - the Gnat beat me whilst I was typing.

Where in Wisconsin are you?

 

Throttle shaft seals.
Old.
Cracked.
Leaky.
IN THE CHURCH OF CLEAN


Also, don't tow the bike like that again. The middle gear needs lubrication while spinning (it's always spinning when the rear wheel turns) and the bearings in that location won't be getting fed much (maybe not any) oil.

 

I had a shop clean it and they didn't replace the jets, I don't know why and at that point I didn't know enough about bikes to really understand how carbs worked. I went through the church of clean page but I didn't "break the rack" and separate the carbs because I didn't want to screw anything else up in the process.
The throttle cable isn't hanging up, and I did build my own manometer with trans fluid, mason jars, and rubber tubing.
How do you check the jet sizes?
How much do a set of throttle shaft seals run and how do you test them?

 

Use an unlit propane torch, with the bike running, slowly wave the torch around the carbs and listen for an idle change. That will indicate the leak.

If I understand correctly, a shop cleaned your carbs? Did they replace any of the inside components?
At first glance going to Church is kinda scary, but if you don't rush, take lots of digital pics, notes and drawings, it is not hard at all. IMHO - you are the only one that should work on your bike, there are safety and reliability concerns that no one else will be as meticulous about as yourself.

When you open up the carbs the jets should have a size stamped on their flange, sometimes people drill them out to make them larger . . . not cool.

All of the needed parts are available from XJ4Ever (icon in upper right hand corner). If float needles and seats were not replaced they should be, 30 year old stuff will not insure reliability. You will have to dole out some $$$ to make your bike reliable and safe, but it is worth it.

I am south of Tomahawk, if you are in the area let me know.

 

Those carbs are terrible. Sure like like a typical 'the shop redid them" job........which means "they SAID they redid them, but that means they sprayed some cleaner in their general direction, charge you a whole lot, hope you're pissed off enough so you don't come back so they don't have to work on carbs that they don't know anything a bout because they can't hook them up to a computer cuz they're too old".

Contact me--I offer rebuild services.

Dave F

 

This is what they SHOULD look like.

 

Totally agree on the carbs--I wasted $225 to have a shop clean them. When I went into them they were pretty clean, although the pilot screws had not been removed and cleaned, but still they didn't do a great job and definitely didn't get them properly adjusted. Be sure to move the propane gas around the intake gaskets at the engine--that's where I found my leak.
With all that green Hogfiddles must have cleaned those carbs on St. Patty's Day.

 

They should look like this after you tear them apart and make them"Zestfully Clean" Because throttle shaft seals look like this after 30+ years.

 

Pilot screw plugs made of brass must also be removed, drill press 1/8 drill and small screw and tack puller work very well.
In Canada our bikes came with rubber caps

 

If I understood correctly the OP's pictures were "before" pics - although he does sound like the carbs were sent to a shop and they did NOT break the rack.

 

Yes those pics were the original condition pics, I did send them to a shop to get "cleaned" and they were cleaned but not church sparkly clean like hogfiddles or toomanybikes carbs. Sorry that I don't have any pics of the internals now to show you.

I know I have a vacuum leak on the boot between the carb and cylinder 1 (far left from rider's position). Any one know where I can get them inexpensively?

 

Then if they weren't done like mine or his, THEY WERN'T DONE RIGHT.

 

Make sure it is the boot and not a failed gasket between the boot and engine. Gaskets/ deluxe carb rebuild kit, Master Cylinder rebuild kit, etc. etc should be ordered from XJ4Ever. If the boot itself is leaking then RTV slobbered on with an bicycle inner tube stretched over it works rather well.

Did you read through this?
http://xjbikes.com/forums/threads/the-information-overload-hour.27544/

 

So basically what I'm hearing is that I need to clean the crap out of them both literally and figuratively, break the rack to replace the throttle shaft seals, figure out what size jets I have, and then go from there? And I'll try the idea with the RTV and bicycle inner tube because the cheapest I've found the manifold boots for is $50+ for used ones

And I basically have all of these symptoms:
- Poor acceleration; the engine feels flat.

- The engine won't respond when the throttle is snapped open, but it picks up speed as the throttle is closed. (A too-large main jet also mimics this symptom.)

- Idle speed falls after you blip the throttle, then creeps back up.

- The engine runs hot, knocks, pings and overheats.

- A lean pilot circuit condition can be responsible for a creeping or hanging high idle, where the rpms stay high then slowly drop down to the set point.

- The engine surges or hunts when cruising at part-throttle.

- Popping or spitting through the carb occurs when the throttle is opened. Or popping and spitting occurs through the pipe on deceleration with a closed throttle.

- The engine runs better in warm weather, worse in cool.

- Performance gets worse when the air filter is removed.

- Fuel levels that are too low will cause a lean condition.

- In cases where an overly lean fuel condition is suspected, the application of a small amount of "choke" may decrease or eliminate the symptoms.

 

Ding, ding, ding
We have a winner
All of the above
Your well on your way to a great running bike.

 

Plus all the other things that need to be inspected and tended to for the bike to be safe.

 

So what's the easiest way to zestfully clean them after they've been tarnished for 30 years and the sediment is baked on? Soak them in carb cleaner and hit them with a tooth brush? I don't want to damage them, but I want to do this the most effective way possible.

 

Also, on a completely unrelated note, if anyone knows someone who wants a Wind Jammer III I'm more than willing to part with mine so I can buy carb parts Also, everyone should take a moment and admire the amazing engineering that went into his sissybar back rest with adjustable position so that he could move the backrest all the way up to the front seat...plus the Wind Jammer III was held on by 4 metal pipe clamps...just by that I should have known what I was getting into...

 

Berryman' s gallon of carb cleaner works well for soaking anything that is not rubber coated or solid rubber.

 

How about ultrasonic cleaner ?

 

Send them to me for rebuild services.... that would be the easiest way for you

Dave Fox

 

^^^ that is the easiest way. Dave's reputation is well defined, he does meticulous work and makes it seem easy.


But what fun is that?
Doing the job yourself is the most effective way of increasing your personal knowledge. And testing your patience.
I did mine - made a few mistakes and learned a lot in the process.

 

What what do you mean when you say the engine "knocks?" That does not sound like a carb issue.

 

Could even be as simple as plug wires put on the wrong plugs

 

I'll try to send you a video of the sound. It's coming from cylinder 1, which is also the same cylinder as I have the vacuum leak in.

Ya I'm trying to decide whether to go with Dave or to do it myself. I'd like to do it myself because I've brought the bike this far, but I don't think I have hours to clean it right and get it tuned the way it should be.

 

The air box boots between my airbox and carbs are pretty stiff, anyone know of a way to restore the rubber's flexibility? I've seen some sketchy stuff on youtube and I'd rather use something from a trusted source

 

http://v4musclebike.com/forums/showthread.php?t=13477

 

Have used this with great results. If there to far gone Len@xjforever can get new ones

 

Thanks!

 

Ummm....yeaahhh. With Mjolnir's permission, I'm gonna show you how the shop sent his "cleaned" rack back to him.

If you have a heart condition, or get sudden attacks of nausea or IBS, you may want to refrain from viewing these images. parental guidance is suggested, as some of these may disturb sensitive viewers.

Dave F

 

What the......?!?!? I'm sure I know why fuel levels were screwy now!!

 

Like the dried fuel and jelled fuel? How about the corroded floats?


How about the NOT clean jets..... or the "washer" under #1 main jet?



Errrr.... the plunger assemblies


Yeah, I think I know where some leaks were!


Some of the krispy fuel around ( and IN) the air jets

 

It almost seems like the fuel had turned SO acidic that completely ate up the beanie screenies and this is all that's left.
She is pretty grungy, but it all came apart with little difficulty--- 1 seized bowl-drain screw, but I got it out.


Three of the four fuel valves had this stuff. Some had piles of it in there


Fuel rail and overflow o- rings were so loose they rattled, and just fell out when the rack was broken down. I'm not saying anything about the corrosion.....

 

Well, it's in good hands-- it'll live again. I hate seeing things like this.... it just reinforces how some shops can take advantage of people.

On the other hand, it is kind of fun to see the difference I can make. The smiles that I "see" on people's faces after they fire up the bike and feel It come alive and pull hard again makes it worth it

Dave F

 

That "shop" is a waste of space. I'd be embarrassed to give a guy or girl there bike back and take there money if it looked like that!
Ps these are Paul's carbs going back in bike tomorrow

 

As a side note, what did they charge you for a "carb clean" ?

 

Color me sensitive. Very disturbing.
We are missing a whole lot of integrity in today's society. And that is a glaring example.
Not cool.

 

I think I'm going to go hurl..........

 

You really don't want to know...but hopefully this forum thread will help other guys so I'll tell you, but first I want to say that I had very VERY limited knowledge of motorcycles and what kind of repair and maintenance had to go into them before I sent them so compared to how dirty they were before, they looked a lot better, however, now that I know you should be able to eat off of them, I wouldn't have spent a dime on it. School of hard knocks I guess. So they charged me $200+ and it took them a little over two hours to "clean" them. I don't remember the exact amount because that was 3 years ago.

 

You got off easy then, consider that the cheapest "fine" you could have paid for this lifelong, invaluable learning experience.......

 

Unless you have someone like Dave do the work, you are better off doing it yourself. Even then you will learn more by doing it yourself. It is not hard. I am a horrible mechanic, but can work on these bikes. Folks here will help you out and there is detailed instructions on the site. Len (XJ4ever) is a great resource for parts.

 

We've all been there at some point. We live and learn. Some find out in time, others only find us during the 'after-search' when a shop shafts them. That's when it really hurts, cuz the lost time and especially the $ can't usually be recovered. So....we move forward.

When you get your rack back, you'll be SO much happier, and you'll fall in love with your bike all over again.

A couple things to remember--

1. Do your valve clearances while the carbs are being redone. You don't want to get it dialed in, then change the shims and find out that you now have to do all the balancing and dialing-in all over again......

2. Clean and polish your Bike now--- if you don't the really clean carbs will make the rest of the bike really look beat.

Dave

 

Yup I already did the valve shim clearances and I had one of my friends who is a professional detailer clean the chrome and stuff and I'm gonna do somemore work on it

 

This is how your 85xj700 will run after you get carbs back on it... oh nuts video file too big

 

I thought it was running so well and went by so fast that I missed it.....

 

Hate that, want to post 10 second video
Error file too large&;&;;&&;&? I'm guessing premium membership would fix that