Announcement

Collapse
No announcement yet.

typical misfire problems?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    typical misfire problems?

    Hi all. New to the forums. I've got an 82 gs850 that ive had for about four years. Its got 12k miles on it so far and has been great until now. It seems to be running on three and a half cylinders. My number one pipe is two hundred degrees less than the rest. Ive checked the plugs, wires, electrics, no problem found. Ive pulled the carbs, took apart number one and cleaned it up. Wasn't bad. Compression is good, within ten on all cylinders. I don't know these carbs at all, don't know what to look for. It back fires through the exhaust with the choke on and through the carbs with the choke off. Any common issues I should look into? Thanks.

    #2
    So, what have you done to it since you got it?

    Adjusted the valves?

    We know you haven't clenaed the carbs

    Check the Top Ten Newbie mistakes and see how many you've skipped

    A 30 year old bike needs some work done on it
    1978 GS 1000 (since new)
    1979 GS 1000 (The Fridge, superbike replica project)
    1978 GS 1000 (parts)
    1981 GS 850 (anyone want a project?)
    1981 GPZ 550 (backroad screamer)
    1970 450 Mk IIID (THUMP!)
    2007 DRz 400S
    1999 ATK 490ES
    1994 DR 350SES

    Comment


      #3
      Yeah, maintenance is calling

      1A) (NEW) Trying to diagnose running problems on a bike with an unknown maintenance history. Common maintenance items like clean carbs, properly adjusted valves, no air leaks in the intake system (airbox, carb boots), a clean gas tank (no rust), and a properly functioning petcock are 100% mandatory for the bike to run properly.



      Mr. Basscliff has info overload- have food and drink handy

      1981 gs650L

      "We are all born ignorant, but you have to work hard to stay stupid" Ben Franklin

      Comment


        #4
        There they are, helpful links. I will review the info and eventually, when I have time, I'll check the valves. Thanks tom203. I now have a copy of the service manual with specs and procedures. That should be all I need. I hope.

        Comment


          #5
          Looks like valve clearance shouldn't be the culprit. I'll have to borrow feeler gauges from work to measure them

          Comment


            #6
            Well, looks like valve clearance shouldn't be the culprit. I'll have to borrow feeler gauges to get measurements but all the tappets rotate freely with cam lobes at bdc. Kinda what I suspected based on the near perfect even compression numbers across all the cylinders. I'm going to concentrate on the carbs now. Going to order gasket kits etc. I don't believe its an ignition issue. I did see evidence of fuel oil goop out of the bottom of the carb to head boot. I'll get gaskets for those as well. If anyone has any other suggestions or tips, HELP is always appreciated. Thanks all!

            Comment


              #7
              Hi,

              Visit the "GS Owners" section and click on the "New Members, CLICK HERE!!" thread. Learn the proper way to clean your carbs, adjust the valves, service the charging system, and all the other regular maintenance items a 30 year old bike needs. Take no shortcuts, especially if you don't know the complete maintenance history. You'll find a virtual GS850G par-tay on my little website.

              Thank you for your indulgence,

              BassCliff

              Comment


                #8
                Originally posted by cs350 View Post
                Well, looks like valve clearance shouldn't be the culprit. I'll have to borrow feeler gauges to get measurements but all the tappets rotate freely with cam lobes at bdc. Kinda what I suspected based on the near perfect even compression numbers across all the cylinders. I'm going to concentrate on the carbs now. Going to order gasket kits etc. I don't believe its an ignition issue. I did see evidence of fuel oil goop out of the bottom of the carb to head boot. I'll get gaskets for those as well. If anyone has any other suggestions or tips, HELP is always appreciated. Thanks all!
                Rotating freely means nothing. The valves are cold when you check, and the clearances shrink with the heat of a running engine.

                Why is there goop under your intake boot? they should be air tight, let alone goop tight.

                Comment


                  #9
                  Basscliff, thanks. I will go there and check it all out.
                  MisterCinders, it looks like an oily colored stain under the boots, like it has a weep kind of leak. I agree that it should be clean and I intend to reseal all the boots so this isn't an issue. I also undestand that rotating tappets don't mean properly adjusted ones which is why I still intend to get some feeler gauges and measure the clearances before I tear the carbs apart. On a side note, the bike is old but only has 13,700 miles on it. This will be it's first "major" service it's recieved as far as I know. Now all I have to do is find the time.

                  Thanks to everyone. All comments welcome.

                  Comment


                    #10
                    BassCliff, hit up your website and downloaded a service manual. Awesome, thanks. I'm going to hit the newbie section next.

                    Thanks.

                    Comment


                      #11
                      Definately go to cycleorings.com and get the intake boot o-rings, they have to be trashed by now. Also I think the valve checks should be done at 6K increments, so at 13K your long overdue.

                      Comment


                        #12
                        As to mileage and valve adjustment, my present motor started with 4,700 miles on it. All the valves were within specs. Two were on the tight side of the specs. The next four thousand miles required four shims to be replaced so don't go with the assumption that you are ok at 12,000 miles. I would guess the most rapid wear is at the beginning.
                        '78 GS1000E, Dyna-S ignition, Dyna Green Coils, K&N pods, Delkevic SS 4-1 exhaust, Dynojet Stage 3 jet kit, Russell SS Brake Lines, Progressive suspension, Compu-Fire series Regulator 55402 and Advmonster cree LED headlight conversion.

                        Comment


                          #13
                          I bought the bike with 10k on it about 4 years ago. Been riding it off and on since then. No problems till now. I researched the o rings and will by them and the carb kits. Not nearly the expense I thought it would be so it's going to get done no matter what. Still haven't measured the valve clearance yet. Been busy at home with construction and clean up. Do the 850's run really well compared to others? I've ridden a yamaha virago 750 before. I know it's a twin and not really comparable but the difference between the two is fantastic. I've had friends on my 850 before that have commented on how well it ran.

                          Comment


                            #14
                            The 850 is not an arm-straightening power house, but it's no slouch, either.

                            Many of us feel that it is probably the best all-around bike that Suzuki produced. I have three of them in the stable at the moment (you can see two of them by clicking the links in my sig), my two sons also have a 650 and a 1000. The 1000 is noticeably stronger, but not quite as smooth. I am told that the 1100 has even more power, but is again, not quite as smooth as the 1000. It's hard to beat the 850.

                            .
                            sigpic
                            mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
                            hers: 1982 GS850GL - "Angel" and 1969 Suzuki T250 Scrambler
                            #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
                            #2 son: 1980 GS1000G
                            Family Portrait
                            Siblings and Spouses
                            Mom's first ride
                            Want a copy of my valve adjust spreadsheet for your 2-valve per cylinder engine? Send me an e-mail request (not a PM)
                            (Click on my username in the upper-left corner for e-mail info.)

                            Comment


                              #15
                              Hey CS, don't get carb kits as they are useless. Just get the orings from www.cycleorings.com and bowl gaskets.
                              Cowboy Up or Quit. - Run Free Lou and Rest in Peace

                              1981 GS550T - My First
                              1981 GS550L - My Eldest Daughter's - Now Sold
                              2007 GSF1250SA Bandit - My touring bike

                              Sit tall in the saddle Hold your head up high
                              Keep your eyes fixed where the trail meets the sky and live like you ain't afraid to die
                              and don't be scared, just enjoy your ride - Chris Ledoux, "The Ride"

                              Comment

                              Working...
                              X