690R carburetor conversion mod.

Discussion in 'Thumpers' started by Visigothic, Feb 27, 2011.

  1. Terlingua

    Terlingua Terlingua

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    I can tell it was homemade. And now that you say that I have seen one on Rototiller site like that. I like it! I have been using a KN so that I could use my air box for tools.
    outbacktm likes this.
  2. outbacktm

    outbacktm Bullrun Bison Supporter

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    6567B563-4392-4DC8-8F27-E976047234C2.jpeg
    Have a couple hours this Sunday in the garage due to heavy rain was able to get the CDI wiring complete
    Now going through both wiring diagrams and removing anything that I will not need
    So tempted to install and hear the bike fire but decided to clean the wiring harness completely of unneeded wires almost 50% reduction
    I’m starting to be able to read the diagrams fairly effective which I have always felt quite intimidated by before.
    The final pieces arrived this Saturday for the fuel tank plumbing two quick disconnects and a shut off valve for the front tanks as well as other bits and pieces.
    Again this modification fairly simple especially if you know wiring which prior to this endeavor was only a basic skill for me, heated grips, fan, R/R simple stuff.
    I am planning on taking the two wiring diagrams with the lists and highlighting what comes out of the stock wiring loom and the few simple mods for the RR loom, and call that my contribution.
    Fabnut likes this.
  3. outbacktm

    outbacktm Bullrun Bison Supporter

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    Well this morning before another day of firewood duties fired the bike off finally, after a little frustration realized I somehow had plumbed the fuel pump wrong swap the in-line with a vacuum, primed the pump bike runs great.
    Might get a short ride in this eve after firewood.
    Many thanks to all that have added to this thread and responded to private messages.
    I cannot compare the bike to premod as it was not running
  4. outbacktm

    outbacktm Bullrun Bison Supporter

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    Carb float bowl is leaking badly, ordered new seal
    I so wanted to ride it today
    Fabnut likes this.
  5. Fabnut

    Fabnut Been here awhile

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    Wheres your jetting at ?
  6. outbacktm

    outbacktm Bullrun Bison Supporter

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    used your formula
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  7. outbacktm

    outbacktm Bullrun Bison Supporter

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    Float bowl seal fixed the leak issue but now bike will only run for 10 to 20 seconds at a time, it’s a fueling issue I neglected to check the float Height. Fabnut what height did you use? If my memory serves I thought I read 4MM but I reread the whole thread and could not find it
  8. Fabnut

    Fabnut Been here awhile

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    Hope this helps

    [​IMG]
  9. outbacktm

    outbacktm Bullrun Bison Supporter

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    Thank you that is what I was looking for
  10. dirtbikeslob

    dirtbikeslob Been here awhile

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    hi outback,where have you run your return on fuel pump to?
  11. outbacktm

    outbacktm Bullrun Bison Supporter

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  12. outbacktm

    outbacktm Bullrun Bison Supporter

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    Not sure what you mean by “return”, I am using the pump with only one out, one port for vacuum pick up, one port to fuel tank
    Picture does not show connections but one line to carb, one line to intake Barb, one to fuel tank
    Minuki fuel pump one bolt to aluminum inner frame, Nice and secure out-of-the-way.
  13. outbacktm

    outbacktm Bullrun Bison Supporter

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  14. dirtbikeslob

    dirtbikeslob Been here awhile

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    just wondering if pump pressure is overcoming the fuel needle valve pushing fuel out overflow .FWIW ,i have original fuel line from tank feeding pump and flow from pump to carb ,with a t junction and a smaller line returning back to tank ,similar to modern auto fuel system.
    will try and get some pics if anyone is interested
  15. outbacktm

    outbacktm Bullrun Bison Supporter

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    I am interested, will have some time tomorrow to dig into carb and check float level and ...
    I do not have any fuel coming out the over flow but I need to find the issue and I welcome good advice
  16. Fabnut

    Fabnut Been here awhile

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    Vent tubes kinked/blocked ?
  17. outbacktm

    outbacktm Bullrun Bison Supporter

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    Brand new vent tubes no kinked or blockage
    I did make a discovery today bike starts right up cold with a choke idols for about three minutes then dies, push the start button Kranks Kranks Kranks Kranks no start even with starting fluid, the discovery is I turn the key off and on, the bike fires right up. But then will only idle from 10 to 20 seconds and dies, turn the key off and on immediately press the button fired right up
    I did pull the choke to see if it would continue to run does not change behavior

    My take away is that it is it’s an electrical issue most likely the CDI or info to the CDI

    At this point any and all advice is welcome, I was starting to get very discouraged as I pulled the carb all the way down cleaned everything again checked the float which was 8mm, the Jets are correct ( Per Fabnuts listing in the thread ) I did a fine tune of the Excelerator pump it’s perfect all parts in good shape I am thoroughly convinced it is not a carburetor issue. I installed a R&D bowl and a flex jet FYI

    Help please
  18. Fabnut

    Fabnut Been here awhile

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    If you believe its an electrical issue, double check all your connections to the ECU plug & that they are matching to the right connections on the ECU. This might seem simple, but it has been an issue before.

    Check all the connections within the new loom for a tight fit

    Check your earth connections for the CDI and the coil. Make sure theyre tight & have good contact with the chassis.

    Did you set the gap on the pulse generator when you installed the new flywheel. From memory it should .8mm

    Check the HT lead and the plug cap for a good connection

    Is the plug cap new ? They can be an issue

    Change the sparkplug
  19. outbacktm

    outbacktm Bullrun Bison Supporter

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    New spark plug -Yes
    Grounds- checked
    Pulse generator gap .7 mm per thread you
    Triple checked CDI wire order

    Tomorrow will check spark cap
    Coil - planning to hook up volt meter to monitor activity during run time
    Read up on TPS does not seem like it could cause this issue

    When I purchased this bike (stock) it was not running, would blow fuse number one( ignition ) when start button was pressed
    Everything else that runs to the CDI has been replaced, I will bypass ignition “hotwire” hoping there may be a bad connection in the ignition (key)
    I will also triple check the grounds for the CDI and coil
    Things seem to be pointing to the coil
  20. Fabnut

    Fabnut Been here awhile

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    My 990's key barrel ignition started to play up where it would cause the bike to breakdown intermittently, like a backfire while riding & even sitting there idling in the shed it would just stop. Cycle the key & away it'd go again.

    Pulled the barrel apart & a bit of dust had got in there & created a thick paste, for want of another word, with the dielectric grease. Flushed it all with contact cleaner and some new grease & was good to go. Its a known issue with those key barrels on the 990's & I think the 690's run a similar unit. Very fiddly to pull apart, but take your time & itll come apart.

    heres some light reading

    https://advrider.com/f/threads/ignition-switch-rehab-950-adv.1007735/