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.

I need some guidance with my bike.

Discussion in 'XJ Technical Chat' started by Maxwell Partridge, Apr 4, 2020.

  1. Maxwell Partridge

    Maxwell Partridge Member

    Messages:
    115
    Likes Received:
    16
    Trophy Points:
    18
    Location:
    Pennsylvania


    TLDR: Been fighting with the bike for a year to try and get it running right while throwing spare money at it when I get the chance. Rebuilt the carbs, reset the pilot jet fuel mixture. Got it started using starter fluid a few nights ago and ran it long enough to get it up to full operating temperature though was still getting sputtering at low rpm in any gear with severe loss of power when sputtering. Continued messing with the pilot jet fuel mixture screws till they were about 3 1/2 - 4 full rotations out from soft bottom and the bike was running absolutely flawlessly, sputtering gone, had good power all throughout the band. Put high octane fuel in it while out on the same ride to see if that would help further (not sure if it did or not), rode it quite awhile to actually ENJOY the bike for the first damn time since owning it, it was GREAT! I get home and park it, next morning it absolutely REFUSES to start, sputters slightly here and there but mostly has no power while turning over, starter fluid wouldn't even get it to turn over. I reset the pilot jet fuel mixtures screws to 2 1/2 and drained the gas to put regular octane fuel in it (read online that higher octane fuel requires higher compression on cold engines to start), and replaced the spark plugs while grounding them first on the engine to ensure sparking. It acts like it is trying to start a little better now, especially with the choke on, got it back to the point now that a small spritz of starter fluid gets it to actually turn over again.

    I have extra Jets, from left to right -> 112, 80, 43, and 120

    [​IMG]

    Should I try throwing in a size 43 pilot fuel jet and see if the bike is any better? I had high octane gas in the motorcycle the night it was running really, really good. But then once it got cold and the next morning I tried starting it - till now it just refuses to start and sputters on one or two cylinders.

    I just rebuilt the carbs from the ground up by taking them to church, cleaned them out really good, broke them apart for fuel rail cleaning and used carb cleaner inside all the jet passageways, replaced any O-Rings while putting brand new 40 pilot and 122 main fuel jets in it.

    [​IMG]

    This is what the old sparkplugs looked like after I took them out, top row is freshly removed, bottom two is after attempting to clean using Alcohol and a soft toothbrush.

    [​IMG]

    After fresh charge this is the standing voltage of the battery I am using, it says negative because I had one of my prongs in the wrong slot on the multi-meter but it's the same reading either way.

    [​IMG]

    Using a paper airfilter in the stock airbox, I repaired damage to the stock airbox using epoxy to seal the leaks.

    [​IMG] [​IMG]

    I have (since troubleshooting) removed the paper fuel filter and am running a straight line to the carbs, all vacuum ports are sealed.

    Any assistance or suggestions would be appreciated greatly, if anyone suggests that upping the pilot jet might help then I'll throw in the four 43 size jets I have and see if it helps.
     
  2. Pizzaman

    Pizzaman Member

    Messages:
    91
    Likes Received:
    48
    Trophy Points:
    18
    Location:
    north Seattle
    Try push starting it. Roll it down an incline and drop it into 2nd gear. If it starts then your battery or wiring is weak and its dropping the voltage too low to fire with the starter engaged. I had a similar problem and a new battery and fuse box solved it.
     
  3. StahlMaster

    StahlMaster Active Member

    Messages:
    146
    Likes Received:
    33
    Trophy Points:
    28
    Location:
    Southgate, Michigan
    If you had this:
    "and the bike was running absolutely flawlessly, sputtering gone, had good power all throughout the band"
    And now have this :
    "I get home and park it, next morning it absolutely REFUSES to start, sputters slightly here and there but mostly has no power while turning over, starter fluid wouldn't even get it to turn over."

    I would look for an electrical issue. Make sure the spark plug wire caps have good connection with the wires, check for loose or corroded connections. Perhaps a "cold solder joint" in the TCI.
    I'm thinking electrical first.
    If it ran that good once, the carbs SHOULD be fine.
     
  4. Timbox

    Timbox Well-Known Member

    Messages:
    2,278
    Likes Received:
    748
    Trophy Points:
    113
    Location:
    Wisconsin, Tomah
    First off thanks for the great detail for what you have done with your trouble shooting. Also the pics are great and really help those of use trying to help, keep it up.

    When you did the rebuild on the carbs did you wet set the carbs? If you put the bike on the center stand and look at the oil window if it full? If you pull the oil filler cap do you smell fuel? If the petcock has not been rebuilt and if the wet set of float jet is not stopping fuel is could be flooding the engine and or going into the crank case. Could be...

    I would go back to basics, with the plugs out check to see if it will turn over, if so check the spark on each plug to make sure you have a nice blue spark. I don't know what tools you have at hand but using compressed air to blow out each cylinder to make sure they are not flooded might help too. Then put the cleaned plugs back in and see if it will start for you.
     
  5. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
    I think you have the wrong carbs for your bike if you need to put in a 43 you should check the Jets in your carbs to confirm that they are actually for your bike. I believe 43 is a stock jet for your bike. What Jets do you have in it now?
     
  6. Special K

    Special K New Member

    Messages:
    5
    Likes Received:
    2
    Trophy Points:
    3
    Location:
    Michigan
    Plugs 2 and 3 which share a coil don’t look very good. If you unscrew the cap and run your ohm meter thru the cap I’m curious how it compares to caps 1 and 4. I am not sure if your bike should be 5k or 10k resistance. When I resurrected my 550 two caps had corroded so bad they were open. The spark jumped thru the connection but it made the spark at the plug that much weaker. Other than that maybe coil is cracked or otherwise compromised.
     
    StahlMaster and XJ550H like this.
  7. StahlMaster

    StahlMaster Active Member

    Messages:
    146
    Likes Received:
    33
    Trophy Points:
    28
    Location:
    Southgate, Michigan
    This seems like a solid start. I remember when my 82XJ650J would have a hard time starting in not only wet weather but damp, humid weather, I changed the coils and all was good again. I couldn't understand how my bike can run soo good once warmed up and dry but act like an idiot when damp. These bikes need all the voltage/amperage possible when starting. I think we can all agree the available electrical power from these bikes is minimum from the get go.
     
  8. Maxwell Partridge

    Maxwell Partridge Member

    Messages:
    115
    Likes Received:
    16
    Trophy Points:
    18
    Location:
    Pennsylvania
    It's funny you say that because my house actually is located right on a hill. but if I try to drop it down the hill here and got forbid it will not start I am kinda screwed since I have no way of getting it back up to my house..

    I meant as in it will not turn over under ITS OWN power, it will turn over perfectly fine with the battery, sometimes when pressing the starter button it will sit with all the lights off/dimmed for about 2-3 seconds THEN engage the solenoid to enact the starter, but other than that electrical seems fine but not saying I'm an expert and know exactly what I'm doing, were you able to see the video I posted at the beginning of the thread? Also, the spark plug wire caps have all been cleaned out with electrical parts cleaner, used a small brass wire brush to clean them internally, then put "dielectric grease" in each plug to keep out moisture and corrosion since I just got bare metal with the brass brush.

    What is wet-setting a carb? I set the fuel levels by bending the tangs gently using needle nose pliers to 3mm below the carb bowl line on each carb using a PVC pipe and some clear tubing attached to the drain nipple on the carbs, each have been set to the appropriate level. I more or less HAD to do this step because the bike kept flooding out when I put it on the side stand but kept running when on center, with XJ550H guiding me I set the fuel levels that way. Oil level is full using the properly rated oil for the bike (It has the specification for wet-clutch motorcycles, and my bandix clutch is slipping bad but it's just shot I think, it does not really bother me too much though honestly). I have not checked the oil cap for any odor and can check once I start messing with it today and give an update in 3-5 hours. I checked the spark on each NEW plug when installing them, each one was clearly visible and blue, plug three seemed ever so slightly less in terms of strength but they all seemed well enough, I used to ride motocross back in the day and have worked on bikes before so based on my experience the spark SEEMED fine. I used canned air on each cylinder before putting the new plugs in each one. It still would not start even with new plugs and blown out cylinders.

    Well when I was trying to get the bike started before I pretty much fouled out the plugs because I drowned the bike in starter fluid, it was a mixture of me getting very annoyed and confused why the bike ran so good the day prior and now just wouldn't start at all. I have now gotten it back to the stage of being able to start the bike on starter fluid, it will sputter over on its own power for afew seconds before dieing, I'm making sure not to foul the new plugs again so I was VERY SPARINGLY using the starter fluid at this point.

    Should I check standing voltage while under load from the starter/turning over the bike and see how far it drops? The battery in it is not actually meant for this specific motorcycle, it's much bigger than what the battery tray can hold but as 13.14 - 13.20 standing voltage when not under load and 20 CCA.
     
  9. tabaka45

    tabaka45 Well-Known Member

    Messages:
    2,348
    Likes Received:
    494
    Trophy Points:
    83
    Location:
    Brunswick, Georgia
    check the voltage at idle and at about 2500 rpm. Idle should be about 12.8 volts and at 2500 maybe 13.8+. If it is low, as mine was (11.5 at idle and 12.6 at 2500 rpm), check your alternator brushes.
     
  10. Maxwell Partridge

    Maxwell Partridge Member

    Messages:
    115
    Likes Received:
    16
    Trophy Points:
    18
    Location:
    Pennsylvania
    I don't know if you guys can see the video at the beginning of the thread that I posted, I have it set as unlisted but the link is there so you should be able to see it. I cannot check the voltage at idle and 2500 rpm because I cannot get the bike started. I did check the bushes as stated in that video and used electrical parts cleaner + a pencil eraser to clean the contact points and bushes. The bushes still have a ton of life left in them, their by no means ready to be replaced with how much material is left.
     
  11. Jetfixer

    Jetfixer Well-Known Member

    Messages:
    3,173
    Likes Received:
    1,485
    Trophy Points:
    113
    Location:
    Nothern Indiana
    One observation is looks like your throttle linkage at the throttle does not look like it is hooked up it is hanging , try turning in the idle a couple of turns, make sure your petcock is set to fuel ON or PRI , have you opened the drain screws and made sure fuel flows out of bowl?
     
  12. Maxwell Partridge

    Maxwell Partridge Member

    Messages:
    115
    Likes Received:
    16
    Trophy Points:
    18
    Location:
    Pennsylvania
    The throttle linkage is connected and functions properly with fresh coating of WD-40 for lubrication, it has a SMALL amount of tension on it from the idle screw so I don't know what you mean by "does not look like it is hooked up it is hanging". The petcock is in the ON position, it does not have PRI option. I've drained each bowl to ensure fuel flow and had to do that last night when I was swapping the fuel over to regular from high octane as a trouble shooting measure. I drained the tank fully and then drained each carb body, put in about a half a gallon of gas, then added a small amount of Marvel Mystery Oil to help oil and lubricate anything the gasoline might come into contact with.
     
  13. StahlMaster

    StahlMaster Active Member

    Messages:
    146
    Likes Received:
    33
    Trophy Points:
    28
    Location:
    Southgate, Michigan
    You can remove the spark plug wire from the cap. There is a "pin" in the cap that goes into the wire thus contacting the inner conductor. Mine were rusted a bit preventing TOTAL power to the plug.
    I really think you should start with the starting circuit top to bottom, don't assume anything. Special K and Timbox are right on the money.
    Let's get this bike STARTED and then find out what's causing the non-starting issues. Perhaps it IS flooding after sitting or it's just not getting ALL the voltage to the plugs.
    Did you do a compression test?
    Were looking for air/fuel, spark and compression in the proper amounts.
     
  14. Maxwell Partridge

    Maxwell Partridge Member

    Messages:
    115
    Likes Received:
    16
    Trophy Points:
    18
    Location:
    Pennsylvania
    Alright I'll take your guys consideration to heart and start there, Though something else too for my XJ750J, XJ550H was telling me that the pilot jet for gas should be a 43 size, I currently have a 40 in there as was recommended beforehand by himself and K-Moe, assumption is that Chacal might of updated it since then? Would throwing in the 43 size jets real quick make any REAL NOTICEABLE improvement? I guess my question really is as follows: "Would a 03.00 size difference drastically effect how easily the bike would be able to start?" and secondly "I have two Carbs for the bike, their both Hitachi carbs, I also have a random Makuni carb in the parts box that came with the bike too, besides the actual jet sizes is there anything specifically different with the carbs? Non-removable jet sizes, or even different designs? I am positive that I put the correct air main/pilot in, and the fuel are (as stated before) 122 and 40, so I'm just trying to figure out if I need to go all out into ripping into the electrical system or if I should try the other carb first, I really hope the carb I have is the correct one because the other one is really nasty.. I CAN clean it out, but I really don't WANT to."

    XJ550H was telling me that I MIGHT have a set of carbs meant for an XJ650 currently on the bike, besides jet sizes is there really a big difference between the 750 and 650 carbs? When rebuilding the carb that is currently on it I used aftermarket jets, fuel rail seals, and emulsion tubes, could there be something else going on with the carb still?
     
  15. Maxwell Partridge

    Maxwell Partridge Member

    Messages:
    115
    Likes Received:
    16
    Trophy Points:
    18
    Location:
    Pennsylvania
    So with the assistance of XJ550H once again, we have determined that the carb is indeed from a 650 bike..

    "Yep, it would appear that the carb was originally for a 650 then. I'm holding the salvageable jets in my hand right now and I have 2 50 and 4 195 jets. The rest got mangled too roughly when taking them out of the carbs and ended up having to be extracted using an extractor that ruined them.

    So now that we have IDed (atleast what we can only now ASSUME because we don't know if one of the POs swapped jets around on their own into the carbs too) that I am trying to run 750 jets on a 650 carb. The question is, "Besides """SERVICEABLE""" jets, are there ANY OTHER MAJOR differences in the carbs that would effect the ability to start and/or run the motorcycle?"

    So now the question is above as to if running the 650 carbs could be causing this MAJOR upset with the bike, the other carb set I have (actually the carbs in the picture for my profile) appear to be the correct 750 Carbs since the jets I robbed from it for the air jets were correct for my 750 (put into the 650 carbs currently on the bike) and the fuel jets I took from the carbs currently on the bike were 195 for main and 50 for pilot.

    [​IMG]
     
  16. StahlMaster

    StahlMaster Active Member

    Messages:
    146
    Likes Received:
    33
    Trophy Points:
    28
    Location:
    Southgate, Michigan
    "I CAN clean it out, but I really don't WANT to."

    LOL...I'm printing this out and hanging it in my garage!!!!!
     
  17. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
    and the plot thickens air jets indicate euro 650.
    what about the main jets?
    Years & Models: 1980-1 XJ650 4K0 and 4K1 models (UK/Europe)
    Carb Manufacturer: Hitachi
    Carb Series: HSC32
    Carb Model ID: 4K000
    Main FUEL Jet Size: #110
    Pilot FUEL Jet Size: #40
    Main AIR Jet Size: #50
    Pilot AIR Jet Size: #195
    AIR COMPENSATOR Jet Size: unknown
    Starter FUEL Jet Size: #40 (non-replaceable, in float bowl)
    Main jet NEEDLE ID: #Y-11
     
  18. Maxwell Partridge

    Maxwell Partridge Member

    Messages:
    115
    Likes Received:
    16
    Trophy Points:
    18
    Location:
    Pennsylvania
    Well I'm pretty much at a standstill, I just got home with some carb cleaner and other cleaning stuff but I don't want to bite the bullet and clean the "750J" carb unless I absolutely have to since it's just painstaking and annoying to do. Anyone have any idea as to if the 650 carbs (with 750 replaceable jetting) would be the issue here? I don't know if they are pretty much the same exact carb just with different pilot and main jets for gas and air, or if there is something deeper that is mechanically different about them that can be causing my problem.
     
  19. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
    the only thing would be slide needles from 750J carbs put into mystry carbs to complete the transformation you can just swap the whole assembly diaphrams slides and needles.

    you seam to have a set of carbs that belong in europe this could be but more likely the po (previous owner) went to far trying to go to pods. I have been seeing some fb posts where podders are changing fuel jets and air jets. not a good idea IMHO there is a ratio for air jets to fuel jets and increasing them both would minimilize the effect of larger fuel jets. just my personal thinking .
     
    Last edited: Apr 5, 2020
  20. Maxwell Partridge

    Maxwell Partridge Member

    Messages:
    115
    Likes Received:
    16
    Trophy Points:
    18
    Location:
    Pennsylvania
    So quick update, seems the other carb has pilot jets 40, and main jet 110 in it. But the main jets are weird looking, their small and VERY rounded on the edges, they look completely wrong compared to the jets from my main carb currently in the bike.
    [​IMG]
     

Share This Page