1. Hello Guest. You have limited privileges and you can't "SEARCH" the forums. Please "Log In" or "Sign Up" for additional functionality. Click HERE to proceed.

XJ550 Carb clean noob help!

Discussion in 'XJ Technical Chat' started by Dre42, Jul 8, 2020.

  1. Dre42

    Dre42 Member

    Messages:
    34
    Likes Received:
    8
    Trophy Points:
    8
    Location:
    Los Angeles, United States
    Hi all,

    ~BACKGROUND~
    So the time has come for me to clean the carbs on the XJ550 that I got about half a year ago now. It's a beautifully preserved bike with only 11,000 miles on it.

    Riding it has been a breeze, however, I have been noticing problem such as 1. bike only runs with choke on 2. bike bogs/stalls when releasing the clutch 3. bike revs up and hangs at high idle on start up. and more recently 4. there has been some pretty significant loss of power bike barely accelerates.

    So, while the world is slowly coming to an end, I decided I'd spend the last few days tinkering with metals and trying to clean the lungs out for this beast.

    ~GOAL~
    My goal going into this project is to do a B job carb clean while doing all I can to minimize any irreversible damage that I can cause. B level because it's my first time doing this work and I unfortunately don't have a good space to work on these (I live in an apartment with a parking lot :(( ). However, I did get all the tools and a small table to use as a work space and so far it's been working out rather nicely. My main priority is to flush the jets. Second priority is to clean as much of the other parts as I can.

    ~PROBLEMS~
    When I dug in today I was able to take off the carbs just fine. However I started running into a couple problems when trying to split them up.

    1. The brackets holding the carbs together have some bolts that are seized. I soaked them all in WD40 and while being as careful as I could, I was able to get 6 bolts out on the first bracket and only 2 bolts on the second bracket. I stripped one bolt by accident and stopped because I didn't want to strip any more. As of now, the carbs are still stuck together by these brackets with seized bolts. Has anybody deal with this issue before? Additionally some bolts on the carb heads also appear to be stripped
    https://imgur.com/a/cfY7i4H


    I tried using vice grips but to no avail. I have an extractor drill bit set but would hate to cause any irreversible damage to these bolts. My plan is to go to tool shop tomorrow and get an impact screw driver as well as some anti seize grease to keep these bolts from seizing in the future.

    2. With some more time left I decided to jump ahead and unscrew the float bowl cap on one of the carbs. The next thing to do was to pop out the float hinge pin. However I wasn't quite able to get it out. I tried gently squeezing it with needle headed plies but they'd just snap off. I didn't want to apply any more pressure so I backed off. Does anybody have any advice on popping the float hinge pin off?
    https://imgur.com/a/K3DatZp

    Would appreciate any insight tips from the veterans on here. I am trying to be as calculated and informed as I can to do this job to the best of my ability. At the same time I want this job done as quickly as possible.

    ~dre

    P.S. Also while tinkering with the Airbox I took out the filter to find out it's straight from the 80's. It seems like has never been replaced. Half of it is pure black--absolutely abysmal condition. It seems these filters are not airbox specific so I'm planning to just order a generic HiFlo HFA4504 Air Filter for an easy $15.
     
  2. Polock

    Polock Well-Known Member

    Messages:
    9,751
    Likes Received:
    2,093
    Trophy Points:
    113
    Location:
    Beaver Falls, PA
    go to the big box store and get a plastic storage tupperware type box, low and big with a good lid.
    things are going to get oily,stinky and lost and that will stop most of that
    a real JIS driver is a must. i never used a impact driver on carbs, don't think it's too good for the carbs. put that float cover back on.
    get those vise grips back out, that's want you really want to work. this is where a real vise is handy
     
    Dre42 and Franz like this.
  3. jayrodoh

    jayrodoh YimYam Premium Member

    Messages:
    2,522
    Likes Received:
    1,102
    Trophy Points:
    113
    Location:
    Cleveland
    Oh man, if you think riding like that is a breeze, wait till you get it running right!
     
    Dre42 and Franz like this.
  4. Franz

    Franz Well-Known Member

    Messages:
    3,646
    Likes Received:
    1,037
    Trophy Points:
    113
    Location:
    Scotland UK.
    Don't be in a hurry that's how parts get broken. Patience is critical as is attention to detail. Your reward will be getting the bike running the way it was designed to.
     
    Dre42 and jayrodoh like this.
  5. a100man

    a100man Well-Known Member

    Messages:
    1,597
    Likes Received:
    346
    Trophy Points:
    83
    Location:
    Bedford, UK
    This.. that pointy cross head screw driver on your picture is where your problems started, as an interim you could grind the tip flat so it sits better in the screw heads.. Jap screws with a dot on them are JIS type not Phillips or PosiDrive

    BTW you carbs may well be fine - You should really have started by setting valve clearances,.
     
    Dre42 and Franz like this.
  6. Simmy

    Simmy Well-Known Member

    Messages:
    2,261
    Likes Received:
    1,126
    Trophy Points:
    113
    Location:
    Waterloo Ontario Canada
    I've been there. While you still have the head of the screw, take a hacksaw blade and slowly carve a slot into the head. The brackets holding the carbs together prevent you from getting the hacksaw on it. Put on some heavy gloves and fit the blade in there. Once you've got a slot you can fit a big slot screw driver on it. And order your JIS screw drivers today. Start making a list for Chacal, including any replacement screws. Alternatively a Dremel with a small cutting wheel is even more effective.

    You were wise not to put excessive force on those float pins. Put some penetrating oil on the pins, WD40 is not really a penetrating oil BTW. If you can grasp the pin head with needle nose pliers see if you can rotate the pin after soaking. Then brace the far pedestal against something solid while you gently tap the pin through the other one. Be very careful here, too many before you have broken those float pedestals. A small ball peen hammer and a small drift pin is good.
     
    Last edited: Jul 9, 2020
    Dre42 and Franz like this.
  7. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

    Messages:
    19,613
    Likes Received:
    6,703
    Trophy Points:
    113
    Location:
    The City of Seven Hills
    +1 on all of the above.

    FYI WD-40 is not a penetrating oil; it's a water dispersant.
    Get yourself some KROIL, or PB Blaster, or mix equal parts Automatic Transmission Fluid and Acetone. The canned varieties would suit you better since you live in an apartment, but the homemade works the best of all three.
     
    Dre42 likes this.
  8. Dre42

    Dre42 Member

    Messages:
    34
    Likes Received:
    8
    Trophy Points:
    8
    Location:
    Los Angeles, United States
    Thank you for all the responses, I really appreciate it so much, makes it much less overbearing knowing I got a community of pros to back me up on this process. :)

    I'm gonna stock up on some more tools before getting back to those bracket bolts--JIS screw driver , oil drain pan (to clean carbs in, per Polock's advice), quality vise grips (I bought some cheap ones and upon very first use their teeth got thwarted, and the whole tool got twisted out, bah should have known better), as well as penetrating lube, and spring loaded center punch (to possibly use to help get the float bowl pins out). If there's no luck with the pen lube and quality vice grips I'm going to follow up with Slimmy's advice and cut slits into bolt heads and try to twist them out with a flat head screwdriver.

    I'm keeping all the carbs in a plastic bag for now so they don't get contaminated with crap air of the parking lot
     
  9. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
    I wouldn't use a spring loaded center punch you may snap the post or flare out the pin.
    support the post.
    check your inbox for a mikuni manual it is helpful to read



    1sock.PNG drift.PNG use a drift to gently tap it out
     
    Last edited: Jul 9, 2020
    Dre42 and Simmy like this.
  10. Dre42

    Dre42 Member

    Messages:
    34
    Likes Received:
    8
    Trophy Points:
    8
    Location:
    Los Angeles, United States
    good to know! neat trick with the socket head, I'll keep it in mind.
     
  11. Polock

    Polock Well-Known Member

    Messages:
    9,751
    Likes Received:
    2,093
    Trophy Points:
    113
    Location:
    Beaver Falls, PA
    don't do dat
    it's got to spin kind of easy before you even try to pull it out
     
    Dre42 likes this.
  12. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

    Messages:
    14,626
    Likes Received:
    5,008
    Trophy Points:
    113
    Location:
    near utica, new york
    The mikuni pins are pressed in, unlike the Hitachi pins
     
    Dre42 likes this.
  13. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
    yes but he wants to use an auto centerpunch to extract them and may flare the end of the pin
     
    Dre42 likes this.
  14. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

    Messages:
    14,626
    Likes Received:
    5,008
    Trophy Points:
    113
    Location:
    near utica, new york
    Agreed.....but my reply was to the comment about the pin being able to spin before even trying to pull it out.

    I use a very thin punch, and support the other side, like you showed above
     
    Dre42 and XJ550H like this.
  15. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

    Messages:
    8,866
    Likes Received:
    1,780
    Trophy Points:
    113
    Location:
    The room where it happened
    Penetrating oil on the pins/posts before you go whacking at the pin! The very last thing in the whole wide world that you want to do is break a float post.......
     
    Dre42 likes this.
  16. Dre42

    Dre42 Member

    Messages:
    34
    Likes Received:
    8
    Trophy Points:
    8
    Location:
    Los Angeles, United States
    Day 2: Disassembly

    Today I finally got the PB Blaster--the last missing thing I wanted to get before heading down and giving those carbs another go.

    1. I picked up right where I left off--separating the carbs by removing the carb brackets holding them together. As many XJbikes members noted, PB blaster + JIS screw drivers really was the way to go. The hand impact driver was never called into action. All the brackets screws popped off with no major problems (patience was the key--some stubborn bolts required multiples soaks.
    A lot of these bracket screws are in poor condition--screw heads are stripped, many have oxidized threads. Therefore, these screws will be replaced.
    https://imgur.com/6BKchZ0
    https://imgur.com/a/L21uB9a

    2. Next, the carb tops were unscrewed. Fortunately they all came off easily.

    3. Float bowls came off no problem. Once again, some screws have stripped heads and will be replaced. Gaskets were brand new. I suppose the previous owner attempted a carb job and put in new gaskets. I couldn't quite get a handle on gasket for carb #4 and unfortunately it snapped. So gaskets will also be replaced.
    https://imgur.com/ABPV8pY

    4. Next fuel transfer tubes as well as the T-joint were disconnected. Some of these junctions had snapped O-rings which will be replaced.
    https://imgur.com/a/uLjPUK6

    5. Next, I attempted to unscrew the mixture screws and encountered the first problem--carb #3 had a mixture screw with a mangled surface and a cracked pole. Not sure for how to proceed would love to hear some advice. I'm thinking of just leaving it in the carb and just flushing it with carb cleaner and air. The other 3 mixture screws came out fine. They were all set at 2.5 turns.
    https://imgur.com/sLtg0WE

    6. Choke plungers came off with no problems.

    7. Next, it was time to remove the pilot jets. Unfortunately, pilot jet heads were all in abysmal condition. On carb 2 and 3, the brass is completely mangled--it's impossible to even tell there was a slit. On 1 and 4, they are badly stripped to the point where I feel very hesitant inserting a screwdriver and applying any force whatsoever! It seems the previous owner attempted to unscrew them and stripped them. Would love to hear advice about how you guys would proceed in this situation. So far, I'm leaning toward just leaving them in there, blasting them with carb cleaner, air, maybe a guitar string.
    https://imgur.com/ojjK4eM

    8. Throttle needles came out no problem. Upon inspection they appear to be in good condition, although the rubber cup on one is slightly cracked.

    9. Main jet tops and the jet bodies themselves came off no problem.
    https://imgur.com/olQEKQ8

    10. Float needle pins came off no problem (thank you guys for the cautionary messages, I used a 1/4 socket head to support the post and gently tapped out the pins with a screwdriver). No posts were harmed in this process :)


    11. There is a brass jet on top of the carbs. Not sure what it is and if it's worth removing. Would love to know more about it if anybody has any insight.
    https://imgur.com/QPqR82Q

    ======

    Much love to everybody on this forum. There's no way I'd be doing this without your guys' help. I hope you're all staying safe and well in these uncertain times.

    Dre
     
  17. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

    Messages:
    8,866
    Likes Received:
    1,780
    Trophy Points:
    113
    Location:
    The room where it happened
    Typical. Could have been much worse.



    Stripped head: typical. Cracked boss..........unusual, but it happens. It doesn't appear that the crack goes down into the threads, so you should be okay. But the mix screw has to come out, and be replaced. That's a vital components for tuning the engine (its adjustment) and you aren't going to be doing any adjusting on that screw. If you're good, patient, and lucky, then you might be able to drill it out using a small pilot hole, lots of penetrating oil, and then an "ez-out" extractor. Or, a small LH (reverse-rotation) drill bit, perhaps m3 size (the screw uses m6 size threads, and you don't want to get into the threads or the carb body is junk), again lots of penetrating oil, maybe a small torch to heat up the carb body all around that area to get it to expand a bit and break the seizure of the threads.

    If either of those methods work, go buy yourself a lottery ticket or two because it's your lucky day, and you might as well press your odds.....

    If you're not good, lucky, or patient, take the the carb body to a machine ship where they can "jig" it up and get a true straight shot in there with a drill bit to extract the screw. Also take a good carb body with the screw removed to they can see how big and how deep an area they are working with/on.



    Typical. Same thoughts applies as when trying to remove the chewed mixture screw above. Don't leave them in there, you need to get them out so you can get lots of solvent in there to clear out the internal passage of that pilot fuel circuit, it's small and gets clogged and most carb "clean/rebuilds" fail due to those internal passages being blocked with fuel varnish or other debris:

    http://www.xj4ever.com/inside your carbs.pdf


    It's the pilot AIR jet, you can remove it if you want, or just shoot solvent / pressurized air thru it, the passage is huge and doesn't ever get clogged.
     
    Dre42 likes this.
  18. Dre42

    Dre42 Member

    Messages:
    34
    Likes Received:
    8
    Trophy Points:
    8
    Location:
    Los Angeles, United States
    yes I figured those jets would need to be drilled out or something along those lines... *sigh* it's tempting to just leave them in there but that would definitely leave a bad taste in my mouth from a half finished job. I'll get some reverse drill bits tomorrow and dig in. Fortune favors the bold!

    I'll fist attempt to jam the reverse drill bit into the jet hole and then gently turn it with pliers. If that doesn't work I'll try to drill them out.
     
  19. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

    Messages:
    14,626
    Likes Received:
    5,008
    Trophy Points:
    113
    Location:
    near utica, new york
    Actually, the cracked boss for the mixture screw is sort of common—- I’ve had to source quite a few replacement bodies when rebuilding 550 racks.

    here’s why— I’m assuming.....
    When the plug is drilled out, people try to leverage the plug out, having not gotten either a good enough bite to pull it straight out

    Or

    Not drilling a big enough hole. If the hole is too small, the brass plug is too thick... therefore stronger than the thin aluminum, and the aluminum breaks. When the hole is big enough, the brass can deform enough, rather than the aluminum, and get leveraged out.

    Yes, definitely use reverse thread drill bits!! If you don’t, the screw will turn in farther, and probably jam at the bottom AFTER deforming the hole as the tip jams through
     
    Dre42 and chacal like this.
  20. Dre42

    Dre42 Member

    Messages:
    34
    Likes Received:
    8
    Trophy Points:
    8
    Location:
    Los Angeles, United States
    the ez out bits and reverse drill bits came in and I finally took a crack at those pilot jets--the most dodgy, ''fingers crossed'' situation of this whole operation it seems. I started by soaking the pilot jets over night with penetrating oil. The next day I drilled out the hole inside those jets just a bit so I could stick the extractor bit inside with less force from the hammer. Additionally, I tapped the pole lightly with a JIS PH#4 screwdriver bit head in an effort to loosen the threads. Then I put on the extractor #1 bit from the set into the drill and inserted it inside the jets. Several of the jets popped right out as I started turning the drill bit. However some of them really were stubborn. I was tapping at those poles, putting penetrating oil inside them for a good hour and a half. However, they all did come out eventually. Onto the cleaning now.
    https://imgur.com/zjzoQsE
    https://imgur.com/7OpFCw1
    P.S. I bought the 10 piece Hanson cobalt extractor set. It was about $40 on Amazon.
     
    hogfiddles and chacal like this.

Share This Page