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I need more power, Scotty!

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    I need more power, Scotty!

    First, my apologies for not hitting "Search". I'm "on vacation" trying to do 5 things at once while dealing with bike issues. (Heck, this bike may have subscriptions, not issues...:-D).

    I have a 1978 GS750(E?) that I came to Oregon to pick up. durinbg storage the last few months it has been garaged. It has been started pretty regularly (monthly) over that time, but not run down the road too far until recently.

    The idle has been "off", idling low and dying. When we were trying to adjust it, it then wanted to idle at 2k.

    I thought we had all the bugs worked out, but here's a description of what happened last Thurday:

    The 750 started off running well. When we started getting into hills though, the first issue cropped up: lost power. I could hold speed (70mph/5k rpm) on flat sections, but going up hill when I rolled on throttle to try to maintain speed, it wouldn't hold well or, when pinned, I would lose power and slow more. I could downshift to 4th, but this would only help keep the speed limit- max under load on a hill was 6k rpm.

    Upon further testing on the freeway I discovered that on downhill sections I could go faster in 5th, but not more then 6k. 4th gear downhill was good for 80-90 mph, 7k or a little more. If I engaged the clutch, the engine could/would accelerate to near redline. I wasn't noticing any missing or backfiring, it felt/sounded like it was running smooth.

    The next issue came up when we stopped for gas. The engine died at a stop sign (Dave & I had been working with the idle speed among other things the day before) and I didn't have enough battery power to start using the "easy button"-I had just enough power to crank once or twice slowly. I bump started the bike and got to the gas station, where Bob was
    waiting. We poked the battery with a meter and found it was low (of course), about 11.5 volts. After kick-starting the bike, he put the meter on and found I wasn't getting much more charging power at all, maybe 1/2 a volt at the most. While revving the engine for volt testing, I did notice one puff of darker exhaust, but otherwise the pipes were putting out clean looking emissions.

    And, I'd burned 3.88 gallons of gas in 93 miles.

    I turned off the headlight and limped back to Eugene. I hoped that I could make it or get close before the battery completely died. I had the same problems with power loss under load. Not only did I make it back, with the headlight off I charged the battery enough to be able to start it again...

    Any help, suggestions, or links to previous threads with help would be greatly appreciated.

    Thanks,
    RK

    #2
    Seems like the bike is not charging. I think that year also had a points and condenser ignition system. You need to get a proper charge rate with a fully charged battery before you can chase any other gremlins.

    Comment


      #3
      Did it run any better after you put gas in it ? Maybe you had some old bad gas. Try a little seafoam too. As for the battery check the water level and trickle charge it over night. Id get a can of contact cleaner and go through all the wire connectors.

      Good luck & Welcome !!
      82 1100 EZ (red)

      "You co-opting words of KV only thickens the scent of your BS. A thief and a putter-on of airs most foul. " JEEPRUSTY

      Comment


        #4
        Nope, didn't help. I just filled it with 4.5 gallons... on 103 miles. Seafoam purchased, battery will be tested and charged as needed, then going from there.

        Thanks for the welcome. =)

        Comment


          #5
          Sooo....... friend who previously owned a '79 GS750 said to check the starting system, start the bike and disconnect the battery: if it stays running, you have other issues, if it stops running, you have charging system issues. Is he correct or is he :---)?

          I ask because I tried his suggestion and the engine stops, but I'm not sure if it's because I opened the circuit by dc'ing the battery or not.

          Comment


            #6
            Hey howdy hey!

            Mr. Fireground,

            Let it be known that on this day you are cordially and formally welcomed to the GSR Forums as a Junior Member in good standing with all the rights and privileges thereof. Note that "good standing" implies pictures! :-D

            Be sure to check all electrical connections, especially ground connections, and clean them thoroughly. Run a dedicated ground wire from your rectifier/regulator to the negative terminal of the battery. If your components are otherwise good, this will help the charging system.

            The good folks here are teaching me to be a better motorcycle mechanic and a better motorcycle rider. Stick around and they'll do the same for you. This is a great community.

            Thank you for your indulgence,

            BassCliff
            (The unofficial GSR greeter)

            Comment


              #7
              Originally posted by Fireground View Post
              Nope, didn't help. I just filled it with 4.5 gallons... on 103 miles. Seafoam purchased, battery will be tested and charged as needed, then going from there.
              And when I removed the battery to inspect, refill, and and possibly charge, I wound up going to buy a new one. The outside cells were dry, the four inner cells were full. The battery was installed 10/16/06.

              Bought connector cleaner the same trip, checking & tightening will be happening soon as well as the ground wire suggestion. (any particular gauge? {not a wise-a** question, being serious})

              Thanks for the "unofficial" greeting, Basscliff, though the pic you have could get you in treble and I'd hate to see anyone resort to violins. B Sharp, and remember: "There's always room for Cello"... 8)

              Comment


                #8
                Who in the hell would be dumb enough to ask Scotty for more power? Scotty is the least powerful man I know! :-D

                Comment


                  #9
                  Originally posted by Grandpa View Post
                  Who in the hell would be dumb enough to ask Scotty for more power? Scotty is the least powerful man I know! :-D
                  I beg to differ... if Scotty is unhappy, that starship ain't going ANYWHERE!

                  YDefinitionOfPowerMV:-D

                  Comment


                    #10
                    Personally I would use a 10-12 gauge wire to run from the Reg ground to the battery. You would have to have the engine running at least 2K rpm for your test. DO NOT DO THIS TEST ON YOUR CAR OR ANY MOTORCYCLE WITH ELECTRONIC IGN.

                    Comment


                      #11
                      Originally posted by Fireground View Post
                      Sooo....... friend who previously owned a '79 GS750 said to check the starting system, start the bike and disconnect the battery: if it stays running, you have other issues, if it stops running, you have charging system issues. Is he correct or is he :---)?

                      I ask because I tried his suggestion and the engine stops, but I'm not sure if it's because I opened the circuit by dc'ing the battery or not.

                      Don't do that, that can screw up the ignition, and lots of other electrical stuff.
                      It also doesn't really tell you anything.

                      Go through the stator papers, they give better tests.

                      Before you do anything else I would do the ground wire (10 or 12 guage ... in a pinch you could get away with 14 guage, but no smaller)

                      Also, get rid of the bullet connectors in the stator wiring, bullet connectors are crappy by design.
                      A lot of people direct solder them, but I don't think thats quite necessary.
                      Cut them out, and replace with blade type connectors, which make much better contact.

                      Comment


                        #12
                        Originally posted by Fireground View Post
                        I beg to differ... if Scotty is unhappy, that starship ain't going ANYWHERE!

                        YDefinitionOfPowerMV:-D
                        It's obvious you don't know that this is a joke on our Scotty, Dom Scotto, who makes a nuisance of himself around these parts. We love Scotty, though! :-D

                        Comment


                          #13
                          This pun's for you!

                          Originally posted by Fireground View Post
                          Thanks for the "unofficial" greeting, Basscliff, though the pic you have could get you in treble and I'd hate to see anyone resort to violins. B Sharp, and remember: "There's always room for Cello"... 8)
                          Mr. Fireground,

                          You're a punny guy, aren't you. :-D

                          Thank you for your indulgence,

                          BassCliff

                          Comment


                            #14
                            Originally posted by BassCliff View Post
                            Mr. Fireground,

                            You're a punny guy, aren't you. :-D

                            Thank you for your indulgence,

                            BassCliff
                            Just letting the punishment fit the rhyme. \\/

                            New battery, Seafoam in the tank, new plugs, and things were running ok. Took off for the barge to get the bike home Tuesday. Plan A was putt 1/2 way up the slab from Eugene and see how things were going... if the battery was needing a charge, pull over for the night, or keep going to the Seattle area.

                            Made it to Seattle in one day, but it took 4 fuel stops. The Seafoam helped some, but it still is burning more fuel than normal. Plugs are very sooty. After a few dozen miles with the additive, I was able to get 6-6.5 k rpm in top gear, though.

                            Bike is safely (?) on the barge, should get here Monday and be ready for pick up Tuesday. By then my GS750 book should be here too and I can start the real testing/troubleshooting/poking around.

                            Thanks for the help & suggestions, I'll probably be back for more in the coming months.

                            Comment

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