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New owner of a 77 Gs750B, wont start.

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    New owner of a 77 Gs750B, wont start.

    Hello,
    I recently purchased A 1977 750b that I am planning to restore. The problem I am having is no spark. The previous owner has had since new and rode up until 2 years ago. Since his last ride it has been stored in a heated garage. There were not any problems with the bike when he parked it, but after retrieving the bike, I drained the tanks, replaced the air filter, and changed the spark plugs and battery. All I am getting is the motor cranking over and no spark. Is this a common problem that has to do with the contact breaker, or should I look at the coils instead.
    I also had a plugged up front master cylinder that looked like someone filled it with ear wax. I have since replaced but was wondering what would cause that to happen to the brake fluid in 2 years.

    Any help is welcome as I believe this project may take some time for me to be satisfied!!!

    #2
    Hee Haw Howdy!

    Hi Mr. CoryLorincz,

    Take the time to clean evey electrical connection and ground on the bike. Then start your troubleshooting. Lots more information right here in your mega-welcome!

    Dear fellow GS rider,

    Let it be known that on this day you are cordially and formally welcomed to the GSR Forum as a Junior Member in good standing with all the rights and privileges thereof. Further let it be known that your good standing can be improved with pictures (not you, your bike)!

    Perhaps you've already seen these, but I like to remind all the new members. In addition to the
    carb rebuild series, I recommend visiting the In The Garage section via the GSR Homepage and check out the Stator Papers. There's also a lot of great information in the Old Q&A section. I have some documentation on my little BikeCliff website to help get you familiar with doing routine maintenance tasks (note that it is 850G-specific but many tasks are common to all GS bikes). Other "user contributed" informational sites include those of Mr. bwringer, Mr. tfb and Mr. robertbarr. And if your bike uses shims for valve adjustments, send an email to Mr. Steve requesting a copy of his Excel spreadsheet that helps you keep track of clearances, shim sizes and other service work.

    These are some edited quotes from one of our dear beloved gurus,
    Mr. bwringer, with ideas on basic needs (depending on initial condition), parts, and accessories.
    ***********Quoted from Mr. bwringer************

    Carburetor maintenance:

    Replace the intake boot o-rings, and possibly the intake boots. Here's the procedure:

    Here's an overview of what happens with this particular problem:

    You'll also want to examine the boots between the carbs and the airbox. There's a good chance these are OK, but check them over.
    And finally, if things still aren't exactly right, you'll want to order a set of o-rings for BS carbs from the GS owner's best friend, Robert Barr:
    http://cycleorings.com
    Once you receive these rare rings of delight, then you'll want to thoroughly clean and rebuild your carburetors. Here are step-by-step instructions that make this simple:

    ***********************************
    Every GS850 (and most other models) has (or had) a set of well-known issues that MUST be addressed before you have a solid baseline for further troubleshooting. It's a vintage bike, and it's quite common (as in, every single GS850 I have had contact with) that there are multiple problems that have crept up and slowly gotten worse over the years. It's not like a newer vehicle, where there's generally one problem at a time.

    These common issues are:

    1. Intake O-rings (install NEW OEM or Viton only - common nitrile O-rings will quickly deteriorate from heat)
    2. Intake Boots (install NEW -- these cannot be repaired)
    3. Valve clearances (more important than most people think)
    4. Carb/airbox boots
    5. Airbox sealing
    6. Air filter sealing
    7. Petcock (install a NEW one)
    8. On '79 models, install new points or Dyna electronic ignition (or at least verify that the old points are working correctly)
    9. On all models, it's fairly common to have problems with the spark plug caps. These are $3 or $4 each, and often worth replacing if you're keeping the stock coils/wires.
    10. Stock exhaust with NO leaks or holes -- good seals at the head and at the junctions underneath.
    ***************************************
    OEM Parts/Online Fiches:

    I would definitely double and triple the recommendations to use Cycle Recycle II and Z1 Enterprises as much as possible. These guys are priceless resources. Z1 tends to have slightly better prices, CRC2 has a wider range of goodies available. If you're near Indy and can bring in an old part to match, CRC2 has a vast inventory of used parts.
    http://denniskirk.com - Put in your bike model and see what they have.
    http://oldbikebarn.com - seems to be slowly regaining a decent reputation, but it's still caveat emptor. They don't have anything you can't get elsewhere at a better price anyway.
    http://www.babbittsonline.com/ - Decent parts prices. Spendy shipping. Don't give you part numbers at all. Useful cross-reference if you obtain a part number elsewhere. Efficient service.
    http://bikebandit.com - Fastest. Middlin' prices. Uses their own parts numbering system to obfuscate price comparisons -- can be very confusing for large orders. Cheapest shipping, so total cost usually isn't too bad.
    http://flatoutmotorcycles.com - Slow. Cheapest parts prices, crazy shipping costs. Don't expect progress updates or much communication. Real Suzuki part numbers.
    http://alpha-sports.com - Exorbitant parts prices. Different type of fiche interface that's quite useful at times, especially with superceded part numbers. Real parts numbers. Shipping cost and speed unknown due to insane, unholy pricing.

    Stainless Bolts, Viton o-rings, metric taps, dies, assorted hard-to-find supplies and materials, etc:

    http://mcmaster.com - Fast, cheap shipping, good prices. No order minimum, but many items like bolts come in packs of 25 or 50. Excellent resource.
    http://motorcycleseatcovers.com - Great quality, perfect fit (on original seat foam), and available for pretty much every bike ever made. Avoid the textured vinyl -- it's perforated.
    http://newenough.com - You DO have riding gear, don't you? Great clearances, always outstanding prices and impeccable service.
    ***************End Quote**********************
    Additional parts/info links:

    GSR Forum member Mr. duaneage has great used upgraded Honda regulator/rectifiers for our bikes. Send him a PM.
    New electrical parts:
    http://stores.ebay.com/RMSTATOR or http://www.rmstator.com/
    Aftermarket Motorsport Electrics parts for motorcycles, dirtbikes, atvs, motosport vehicles manufactured and distributed by Rick's Motorsport Electrics


    For valve cover and breather cover gaskets, I recommend Real Gaskets (reusable silicon):
    http://www.realgaskets.com
    The Rice Paddy (salvage/used)
    http://www.ricepaddymotorcycles.com
    Carolina Cycle
    http://www.carolinacycle.com
    Ron Ayers Motorsports
    http://www.ronayers.com
    MR Cycles
    http://www.mrcycles.com
    Moto Grid
    http://www.motogrid.com
    If all else fails, try this:
    http://www.used-motorcycle-parts.org/
    Used bike buying checklists:

    http://www.clarity.net/~adam/buying-bike.html
    Lots of good info/pictures here:
    http://www.suzukicycles.org
    http://www.cyclechaos.com/wiki/Motorcycle_Wiki
    http://www.bikepics.com

    Basic motorcycle maintenance/repair:
    Motorcycle Repair Information, Do it Yourself Motorcycle Repair Course, .



    Thanks for joining us. Keep us informed of your progress. There's lots of good folk with good experience here.

    Thank you for your indulgence,

    BassCliff
    (The unofficial GSR greeter)

    Comment


      #3
      Thanks

      Wow now that is a welcome post a wealth of info , thank you and i will post pictures as my project progresses !

      Comment


        #4
        i really dig your signature!

        check the voltage at the coils
        it is unusual that both coils would fail at the same time
        clean all the electrical connections including the fuses - it may well be that the fuse is out or not conducting well due to corroded connections
        to test for spark, take all sparkplugs out, plug them into the caps, ground them to the engine and push the starter button - you should be able to see the sparks
        GS850GT

        Comment


          #5
          How about running a matchbook cover between both set of points to clean em out then check to see if you get spark? It is doubtful that both coils went bad.

          Comment


            #6
            I agree. Likely both coils wouldnt go bad at the same time. The usuals apply, check the battery, the points, and the coil leads.

            Comment


              #7
              Finally got it started !!! IT purrs!!!!

              Today my brother, Owner of GapRyders Motorsports came over to help me out with a bunch of goodies!!! New handlebars, all new fluids, and my factory paints!!!! I had been working on the starting problem for about an hour when he arrived. I had tried the usual recomendations, checking the plugs cleaning the contacts etc. Still no spark!!!! Up walks my brother!
              He turned on the key and the dash lights were working!! The contacts were getting spark, and when he pulled the plugs we had spark there as well. I still dont know what the problem was so will clean all connections. But, He fiddled with the throttle, the choke and the petcock. And we were running !!!! Man she sounded sweet !!!! Thanks for the input Will be posting pics of this project in the upcoming days!!!

              Comment


                #8
                Welcome aboard!! Good to see another 750B coming back to life..

                Comment

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