Were any new xj bikes just lemons?

I had my carbs off and apart so many times it makes me sick. I got the drill from Len for the starter jet. I cleaned them out flushed with carb cleaner and blew out with compressed air. STILL won't start without starting fluid although it did restart after sitting for 7 hours in 45 degree weather which is an improvement. Running on 2 or 3 cylinders now like it was that day after I got it. It ran fine after warming up but the second day was not good. Then the carb BS started. My bike was in near new condition with 5800 miles on it when I got it a year ago. I put 1100 miles on it since then. Could this bike, or just the carbs, be defective? Is it possable it ran for a year or two and just was too much of a PITA to keep running and so it sat in 3 other owners garage all this time? Its not like I'm mechanically DEclined. My automatic 5.0 mustang went from high 15's to 13.55 with a 2.6 deep staging 60' at 107mph. 107mph means an easy 12.6 with decent traction and shallow stage. This took me working alone all of a saturday and half of sunday to do. I can't believe all the problems I'm having with this bike JUST TO GET TO RUN. Does anyone have a known good working set of carbs for an 82 xj650 they want to sell or try if you're close enough to chicago?

 

Have you tried ebay??? Are you in Chicago, or close to?

 

Jim,

Don't get discouraged. These carbs are by far the most tempermental things I have ever worked on. Lets start from scratch.

When you took them apart did you:

Soak the carbs in carb dip?
Run wires through all the passages?
Set the float levels?
Put the rubber boots on the enrichment plungers?
Clean the brass tubes that go down into the wells (where the small jets in the float bowls are) ? Also small bleed hole up top by the carb body ?
Change the throttle shaft seals ?
Bench Sync and do final sync when on the bike ?
Intake boots in good shape and not cracked and clamps tight?
Check for Vacuum leaks with unlit propane tourch ?

If the carbs suck any air from where they are not supposed to it will cause problems. After all that could it be electrical. Is your battery up to spec. ? Is the charging system up to spec.? If your voltage is low the ignition system will not work right. Lots to look at you never know what Gremlins you have there. Take a deep breath and crack a beer and look it over again. The key here is that it all has to be right to run right. Let us know.

 

MN-Maxims is on the right track. He brought up two REALLY pertinent aspects:

If the carbs suck air from ANYWHERE other than they're supposed to it WILL cause problems; and a weak battery will drive you NUTS.

Remember also, rust in the gas tank was a problem with XJs before the dealer ever sold them. Some of the few tech bulletins I have seen for XJs are for the dealer on how to deal with rust in the tank.

An in-line fuel filter is a must, rust can dissolve into particles smaller than the petcock screen can filter out. In all of these subsequent carb 'sessions' have you checked the little filter screens on the float needles to be sure they weren't plugged up again?

Last but not least: I FEEL YOUR PAIN. But know this: A 27 year old bike is a 27 year old bike no matter how LOW the mileage on it is. I'm "almost there" on a low-mileage bike myself (7100 miles) and it has taken EASILY 3X the time, effort and money that my '81 with three times the mileage took to get back on the road. That's not counting my customizations.

You get to replace things that have dried out and crumbled rather than worn out; but they still have to be replaced. Look on the bright side (I keep telling myself this) you're gonna have a BRAND NEW 27-year old bike when you're done. And really, it IS pretty cool (I've managed 89 "new" miles so far.)

While you're at it, look at this: http://xjbikes.com/Forums/viewtopic/t=15874.html then go check your rear brake. It'll take your mind off the carbs for a while.

That beer probably isn't a bad idea either.

 

New throttle shaft seals, soaked carb bodies and bowls for a week. The same cleaning solution made brass emulsion tubes shine in 24 hours. I left them in there for a week as well. I got the carb sync tool from Len and used Rickomatics advice for bench sync. I got the bike to run great but the cold start has always been a problem. I'd get 2 hours in the summer after shut off before I needed starting fluid. Now I went 7 hours in 45 degree weather. I had a real hard time starting the bike in 45 degrees with starting fluid before the drill trick. It seems like I need to turn the main idle screw up or keep working the throttle to keep it running when cold. Today its running on 2 or 3 cyclinders like I left a stray electron in the carb somewhere and now it will not run right. Pisses me off. Makes me want to work on the stang instead. I could tool with that everyday and by taxday, pickup 2 heffers from jenny craig, stuff them into the backseat and passenger seat and still blow away the new 2009 v max.
aaaaarrrrrrrggggggg!!!!!

 

I have an inline filter. I added seafoam and stabil to shell premium gas. I drove it a few times on different days this way. It ran fine but the exhaust smelled strange. I drained the carbs last fall easily because I removed the drain plugs and replaced them with the allen head variety from Len. I did not have to recharge the battery to get it going on starting fluid eventhough it sat all winter in an unheated garage. I live about three miles west of where the cubs loose when they come to chicago.

 

Ok Lets just say everthing else is ok. Lets just focus on the cold enrichment circuit for a moment.

The brass plunger in the top of the carb. You pulled those out and made sure the path was clear all the way down into the little brass tube all the way into the well with the little tiny jet in the bottom. Lets not look at anything else right now. OK

The plunger has a spring on one side so when you move the lever on the left handle bar the cable pulls the linkage up and lifts all 4 of the brass plungers. All that is doing is opening a valve so to speak so fuel will pull up from the bottom of the carb up through that plunger and go through a small port in the top of the throttle bore on the engine side of the butterfly. So if it were clear and working properly fuel should be there and the bike should start and run. Correct. Yes it should. The problem is there is no fuel there. OK. So lets see if we can find out why. The plunger has to have at best some kind of seal (little rubber boot witha hole in it so it seals the plunger shaft). If the boot is gone it can suck air around the plunger and not fuel from the float bowl. So lets assume those are good.
The next step is to look at the little hole where the fuel should come out. Is it plugged with carbon or some other foreign matter?? If its clear we need to look at the passage in the carb body that goes down. I have a blow gun that hasa small rubber tip to get in there so I can blow air through that passage. Note: this is a great place for that white aluminum fuzz to build up and block that passage. Then I would look up that small brass tube that goes into the well in the float bowl. Run a wire up there and see if it goes all the way up or does it stop at the top of the tube? You trouble is right in that area. Look it like this. Your not getting fuel up to the plungers, You'll Find out you need to know more than you want to on how this works. Like Rick and Len say When you think you got it clean you don't. Crack open the beer now and think about it. Oh justr as another little trick if those sealing boots are hard as I would suspect they are you can take some tune up grease and lube those plunger shafts up and that should stop the air leaks for quick tempoary fix

 

I've got a really revolutionary idea. WHAT IF IT'S NOT A CARBURETOR ISSUE?

This bike has 5800 miles on it. As such, it's 800 miles OVERDUE for its INITIAL and most important valve clearance check and adjustment. My 7100-mile bike had never been touched, every single blasted valve needed adjusting but one, and it will need it next time. Have you looked at the valve clearances?

A tight valve will drive you nuts thinking something else.

The fusebox on these bikes, even though appearing PRISTINE is a time bomb. The fuse holder contacts are actually made of brass and plated with some dull silver metal that CRYSTALLIZES the whole thing over time. They can be cracked and you would not know it by looking. Pull your fuses out and start gently squeezing the fuseholder contacts together; report back on how many break right off.

A poor connection will drive you crazy thinking elsewhere. That applies to the entire electrical system by the way.

A weak battery will spin the motor REAL fast, but not have enough juice left to fire the ignition system. You'll get weak, watery or NO spark. I wouldn't have believed this one if I hadn't experienced it. If not 110% sure of your battery, pull it and take it to an auto parts store and have it checked. See what happens with a FULLY charged battery and new plugs.

Have all your starting woes been with the petcock in the "ON" position? Or have your tried "PRI" too, you didn't mention. A lazy/intermittent petcock will also cause short term mental instability. Petcock also susceptible to crud since it's upstream of any additional filter, but that usually causes problems with not shutting off.

I may be COMPLETELY off base with all of the above, but I would hate to see you licking your carburetors clean when the problem is elsewhere.

 

I agree with Fitz on the Valve Clearances. Just cause its been sitting with such lows miles its really possible that those shims in there have expanded or contracted with you riding it and the wicked weather. So, check those valves, re-sync your carbs with the engine and see what develops.
-SLkid

 

Your right Fitz it could be tight valves. I was thinking he just gives it a squirt of starter fluid and it goes. I thought tight valves would give you trouble when it gets warm and the valves hang open and kills the motor. But I'm sure as you are there might be something else wrong. I have went round and round with the enrichment circuits too. Just as an off topic I've had enrichment plungers not seal and made the bike run so rich it would blow black smoke when you cracked the throttle as well as not letting enough fuel to start when cold too.

 

the battery issue was the one that i had. i was even running it off of a car battery just to make sure that i had enough power. i put in a fresh battery made for this bike. and she fired right up. odd eh? the next thing i check is to see if it was running on all four. that was a check so i took her for a ride and i could tell the carbs werent toltaly working properly. but i didnt care i wanted to right it. it wasnt running lean though. just a bit rich. i took it out the other day and it was only running on three cylinders. my guess is that i plug the carbs up with the little bit of old fuel that was in the reserve thank.

the leason learned her is that these bikes take care and attention to get running perfect. mine is low milage is well. it seems that they all are because they stop running before and one can get up to high milage because they didnt take care of them.

and by you buying them for a restoration. is exactly what that means restore it take you time youll get there. nothing ever happens how we want it to. mine is going to be my daily driver in the summer so lets hope that everything work out as planned.

keep at it check it alllllll over before giving up and beer does help. helps calm you down. but can create a problem a problem when you fianly get it running and really want to take it out for a ride.

good luck

 

Ha ha my GF would LOVE if my bike blew black smoke all the time. She drives a Turbo Diesel and thinks its the coolest thing in the world when she smokes cars

 

LOL SL

 

BikeRanger; Solid advice. Don't take on one of these crocks without expecting a bit of a wang-dang-doodle to get it right. I bought my '81 to be a daily rider; it is. But I'm slowly making it better and better, and it really didn't need much except TLC. It had 18K on it and it never sat, or didn't run, I'm the 3rd owner and the PO was a well-intentioned idiot.

My really clean low-mileage '83 on the other hand is rapidly becoming a toxic asset. It's turning out BEAUTIFUL and when I'm done it's gonna ROCK but DAMN. But I'm SOOO close. Just another $10 billion to tide me over, please Mr. Geithner?

 

yeah mine had two previous owners aswell. both were friends and it sat for 6 years in a heated garage took me two weeks to get it to run. now shes in 400 pieces or so (including bolts) but shes getting ready for some chroming and some paint. shell be a beautiful machine once done. the only thing im concerned about is long trips and it being air cooled and all.

pepy little thing though. ill post some pics once im done all of it. im not sure what colour i was thinking a dark purple or a bright orange black frame none the less and chrome everywhere i can put it with out it looking off.

as for your bike i was thinking made some rings are going. if you dont have a compression tester.(like me) i took all plugs out except one and tried to push it. if it moves freely then that cylinder is shot. if its hard to push then your good, repeat for all cylinders and report back shouldnt take long.

 

I gotta side with MN on this -- sounds like 'dem dang starter circuit tubes... The bowls, especially... you can't just run a straight piece of wire through those passages. You kinda have to work it from top and bottom with a piece of a guitar string (high E).. The passage becomes tiny farther down into the bowl where you can't see. You will know whether you did it right -- wrap a carb cleaner straw tip with some vinyl tape so it makes a good seal in the top end of the passage and blast it with carb cleaner. You should get a powerful jet coming out the other end. Reverse the direction. you should get a 4-ft. jet of carb cleaner shooting out... It's also good if you don't look into it as you spray the carb cleaner (gawd that stuff stings) :roll:

These bikes should start first bump, provided you have good compression, spark and a properly exfoliated set of carbs.

 

If there are only 5800 Miles on thjat bike you ought to be able to make it roar!

Cut-out the Fuse Box and Solder >> Solder >> NOT Crimp in a New Fuse Box.
Remove the Ignitor and Clean its Spade Contacts and the Contacts at the Harness.
Assure the Coils are Grounded.

Carb Tuning:
Sync
Set Pilots: Set the TOP of the PILOT MIXTURE SCREW (The Flush Top across the Wing of the Slot) to be --> PRECISELY <-- 7/32nds ::: Seven thirty seconds of one Inch ::: deep inside the Pilot Mixture Screw Housing.

Measured PRECISELY
The Top of the Mixture Screw --> 7/32nds deep. Preset.
Run the Bike. Check the Plugs.
Too Lean? Bring it OUT 1/32 at a time. Check.
Too Rich? Turn it IN 1/32 at a time. Check.

See what that will do for you?

 

I checked the valves. They were on the tight side of ok. I did not replace the seals on the top of the "thingys" that open and close when you move the choke lever. They seemed soft but maybe they are not soft enough to make a good seal. I have Lens brush kit and will take the carbs apart again for a dunk in the tank.

 

Jim

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Year -- Model -- Miles -- Stock or Mods -- (Troubles)

Add your LOCATION. You might ne close to someone who can help.

 

I have a compression tester gauge. It fits big block chevy as well as lawn mower engines. Maybe it will not work with the bike but Ill try. I remember reading in the manual for the bike about making sure the spark can discharge. Can I leave all the sparkplugs connected to the wires setting on the engine away from the place they go into so they will spark as needed? I can easily drain the carbs for safety and let it crank 4 or 5 times to gt a reading on each cylinder. The bike runs great save the cold start problem. I do not think theres a bad cyclinder. It can burn rubber all the way down the street (200 feet)if you dump the clutch at 7k or so and sort of hold on. I blew away a 600 sportbike this way. It took him a long time to catch me after I let off. Gave me thumbs up quite a few times. I'm sure there are 90lb pros who can show me up but I think the bike runs well execept for the cold start.
Jim

 

I'm sure the left 2 carbs got crud in them. I left the bike alone for a few days. Makes me mad. Needs more maint than the space shuttle. I'll get to it this week. Will post comprssion test results just for fun. Thanks for all the help.

 

Took the carbs off and tore them down an did a compression test in only 2 hours. I found a torn o ring on the number 2 (counting left to right while sitting on the bike) idle mixture screw. That screw was in the tightest of them all and I'm not sure if I ripped it while gently bottoming the screws to count how many turns out they all were. When I got the bike, the o ring was missing from this carb. I got a set from Len when I was cleaning the carbs last year. Could it have been ripped all the way through from the I put it together? What effect would a torn idlescrew o ring have on the way it runs? It was on the same side of the engine I suspected a dead cylinder.
From left to right as sitting on the bike they were 41/4, 31/2, 4, and 4 turns out. The plugs were all equally black. That might explain why it seemed to run better and better as it got colder out although I got 50mpg on a half day trip with my windshield on. I was able to ride it this year after I ran the drill through the starter jets. It ran fine like it did all last
year. The next day it ran on 3 cylinders. Bad on the left side. From left to right the compression readings were 145, 150, 146, 150.

 

Compression's fine for a 650 IIRC. ANY malfeasance in the carbs can cause weirdsh*tness. Variation in your screws not out of the ordinary.

When you get the carbs back on, float levels checked with fluid and sync'ed, run a couple tankfuls through with SeaFoam in them, just to be double-dog sure everything is as clean as can be. You do have an in-line fuel filter, right?

New plugs wouldn't hurt and make sure the spark plug wire caps are screwed on fully (how in all blue blazes do they come loose when they can't rotate, anyway?)

Once you've gotten through the bike from front to back it will be nearly maintenance-free, especially compared to say, an old British bike. (Trust me.)

 

All the bowls got some sort of cleaning when I ran Lens drill bit through them. Does the starter jet have anything to do with the way the bike runs in general? I always had clean plugs but now they are all black. I only rode the bike for 15 minutes or so and put it away after the drill treatment on the starter jets.

 

Your bike will not start nor idle unless the enrichment passages can squirt carb cleaner several feet. You have to shove the red straw of the carb spray into the passage and squirt away from your face. If it does not squirt the bike will not start.

Once you get the passage to squirt like a Super Soaker the bike will fire up immediately and purr like a kitten.

My bike started horribly and ran like an asthmatic sloth. Cleaning and synching the carbs makes all the difference.