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Carb issue when starting

Discussion in 'XJ Technical Chat' started by Magiccowinuse, Apr 14, 2019.

  1. Magiccowinuse

    Magiccowinuse Member

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    I know that I have a clog somewhere. The bike runs and idles perfectly. I've got everything synced up nicely. I have cleaned the carbs, but obviously not well enough. When I shut the bike off, it won't start back up without starting fluid. With a small blast of starting fluid the bike turns over instantly and idles just fine.

    Which system of the carbs do I need to further inspect? Obviously I will tear them down again and re-clean them all over again. But there is so much information here, I am unsure which area of the carb is causing this problem.

    Edit:
    After searching for a while, and posting this, I went outside to give a quick try before removing the carbs. The bike started right up.
     
    Last edited: Apr 14, 2019
  2. k-moe

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

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    Did you clean the enrichment jets that are in the bottom of the flost bowls?
    How long are you leting the bike sti before the restart issue comes up?
    Have you checked the valve clearances (yes this is related)?

    Do you maybe have another thread about your bike that contains the history of what you've done?
     
  3. Jetfixer

    Jetfixer Well-Known Member

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    You did not state are you opening the fuel enrichment lever open ( choke)?
     
  4. Magiccowinuse

    Magiccowinuse Member

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    I cleaned every part of the carburetors including enrichment. I may need to clean again. But, to answer questions...

    I did clean enrichment jets. The restart issue would happen 30 seconds or more after shut down. Valve clearances have not been checked this time around. I will check in the coming days. I do not have an recent thread on this. It has been some time since I've had an issue with this bike. I didn't run it at all last year.

    In an attempt to start cold, it wants to fire with ether. But, takes some time. While trying to start cold it is a hell of a lot harder to get started. It seems to be more willing to fire when releasing the starter button than while actually cranking. Maybe not a carb related issue?
     
  5. k-moe

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

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    Do a load test on your battery.
    Has the starter been rebuilt?
     
    Colin 85 700 likes this.
  6. Colin 85 700

    Colin 85 700 Active Member

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    Im with kmoe, you have a high draw or a poor battery, seen a lot of sleds that wil start with rope and not electric start, either weak starter or crappy battery everytime! (Sometimes both... Crappy battery is hard on starter, poor starter is hard on battery)
     
  7. Colin 85 700

    Colin 85 700 Active Member

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    To note: the engine should sing over quite quick, if its laboring at all, theres an issue.
    Ignition and valve timing can effect, however check electrical first, way easier.
     
  8. Magiccowinuse

    Magiccowinuse Member

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    I have not done a load test. But, I have used multiple batteries all of which have been tended all winter on tenders. All with great voltage. Either way a new battery is defiantly in order. The starter has not been rebuilt. I could see this being a problem. There was some clicking/grinding going on occasionally. While I agree these may be contributing factors, I don't think either of these are the root cause. It seems this is an electrical issue rather than a carb issue? I guess I'll try with a new battery and see how it goes.
     
  9. k-moe

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

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    When you let up on the starter button you're reducing the overall electrical load on the system. If anything is drawing too much current (or not providing enough voltage in the case of the battery) the reduction seen with the starter disengaged allows the TCI to finally be able to do its job.
    There are many things to check, but the starter and battery are key suspects.
     
  10. Lodewijk

    Lodewijk Member

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    I recognize that behavior! And echoing the rest of the advice, def. check the battery.
     
  11. Magiccowinuse

    Magiccowinuse Member

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    I have multiple charged batteries i have tested this with. So the battery is out of the question. I get 10.2v at the starter while cranking.

    I definitely have a starter relay to replace. After a few turn overs, it won’t engage the starter for a few moments.

    But, even with that problem, warm or cold, a quick blast of starter fluid across the intake of all 4 carbs she starts right up. Idles and revs fine. It seems to me to be more of a fuel delivery issue during cranking...?
     
    Last edited: Apr 16, 2019
  12. Polock

    Polock Well-Known Member

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    maybe try adjusting the cable to lift the plungers higher
     
  13. RCGolden

    RCGolden New Member

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    Are you starting with the petcock set to prime, on or res? Assuming you have those settings on yours
     
  14. Magiccowinuse

    Magiccowinuse Member

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    Prime.

    The bike will restart no problem if I attempt a restart immediately. If I let it sit off for 10 or more seconds it requires starting fluid to fire again.

    How can I test a weak starter? I will do some reading in the xj4ever knowledge base tomorrow. Too tough on mobile. It has been a while since I’ve had it running normally. So I don’t remember exactly how it used to sound, but I remember thinking that it doesn’t sound like it is cranking as quickly as it used to. How would this effect the starting? Weaker spark until I let off, then it gets a jolt of the spark actually needed and fires? How does that fit with my statement above about immediately restarting?
     
  15. RCGolden

    RCGolden New Member

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    i’M leaning towards a carb issue then. My 550 would do the same. Cleaned the carbs. Would be a hard start or start of starter fluid no problem. Then would be hard to start again. Maybe dirt in the fuel take got into them but I’d clean the again.
     
  16. Magiccowinuse

    Magiccowinuse Member

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    T
    hats happening this evening.
     
  17. 1965soda

    1965soda Member

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    Good morning. You may have already considered this and addressed, but just in case.....

    Is there fresh gas in the tank? Stale gas can cause starting issues.

    Hope that helps and hope you find the source of the issue.
     
  18. Magiccowinuse

    Magiccowinuse Member

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    Absolutely. I Appreciate the help.

    New gas, freshly cleaned (guessing not well enough) carbs. I’ll try another dip this evening. Let them sit longer.
     
  19. k-moe

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

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    Hold on.
    Have you been soaking the entire assembled rack!?
    In what solution?
     
  20. Timbox

    Timbox Well-Known Member

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    Just wanting to clear up what is going on with the cleaning? Have you broken down the carbs off the rack to individual carb bodies. Cleaning them all together in the rack will not do it. Spay and compressed air will only get so far in cleaning, it will not make your XJ run like it should.

    Some types of cleaner will also eat away at all the rubber and felt in the carbs causing more issues.

    Let us know what you have going on with the cleaning. Thanks
     

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