1975 Johnson 135 No spark starboard side

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  • July 5, 2016 at 11:23 am #39626
    fleetwin
    Participant

      US Member

      The sensors are in the timer base.
      But again, I want to re-emphasize Dan’s point about these early engines and cranking speed. It is not uncommon for only two sensors to fire while cranking, then once the engine fires and RPM picks up, the other two sensors kick in. Later, updated sensors had improved windings and were a little closer to the flywheel hub magnet. So, if my crude methods point to the sensors, then go ahead and measure sensor resistances. Replace the expensive sensors if and only if the offending sensor resistance is way off/shorted/open.
      What I am trying hard to avoid is you spending bucks for new sensors (timer base), getting spark on all four while cranking, but still having the engine problem that prompted all this testing…So, again I will ask just what prompted you to check spark. Is this engine new to you? Have you had it running yet? Were you just doing basic tests to evaluate the engine? Or, is there an actual running/starting issue.
      So, if you have never had this engine running, I would go ahead and try to start it, perhaps the other sensor will kick in once the engine fires. This engine is an old 135hp, had lots of compression, detonation/preignition damage is not uncommon. Please inspect it carefully, starting with a compression test. I would also try to sneak a look inside the plug holes with a bore scope if you can get your hands on one. I have seen good compression readings even with partially melted piston domes or broken top rings.
      Again, I am being cautious here because I don’t want to see you spend money needlessly, or on an engine with internal problems….D
      PS- Dan’s point about the early stators (name of assembly that holds the charge coil and alternator windings) is valid as well. Even though the charge coil/stator may not be an issue now, it should be closely examined. The early ones had a tendency to heat up and melt down, you could usually spot a puddle of dark greenish hard goo that had dripped down off the charge coil and on to the block. So, if the original stator/charge coil is still in place, you should plan on replacing that as well. Don’t worry about this unless it is determined that you need to dig into/replace those sensors. Dan said he found a nice used stator for you on ebay.

      July 5, 2016 at 11:41 pm #39654
      wiscoboater
      Participant

        Thank you Don for your help!
        Here’s the background on the motor. I purchased it from a friend that purchased it from the original owners son. The original owner is now diseased. The boat was primary power on his Lake Michigan salmon fishing boat. That tells me the motor was most likely run 3/4 to wide open out to the days hot spot and then spent a lot of time trolling between 2 and 3 mph, then run wide open back home again. The Son stated that before his Dad passed the motor developed some running issues, down on power, running rough. He replaced the rectifier? Not sure why he started there but he did. No change in running condition. As his Fathers health deteriorated, the boat was winterized and sat for 3 years before my friend picked it up. I bought the motor about 4 months ago. When I did, I did a compression test first thing. My low cylinder is 149psi dry, high cylinder is 154 psi dry. I have not started it at this point. I have only spun it with the starter, plugs out and grounded. Thats where I found the dead bank. It was spinning over very well when I did that test. Next test was with new plugs installed (tested on another motor, known to be good) and an inline spark tester. It’s the adjustable open air type, gap set at 1/4 inch. Again, spark like crazy on the port side, starboard nothing. I had a long conversation with Dan today and he instructed me to shoot some OMC engine tuner into the carb bowls through the venturies and let it soak in there for 24 hours to loosen any gum or varnish and then try to start it with fresh fuel tomorrow. He said it may pick up the 2 dead cylinders once it get going and picks up some RPM’s. So that’s where I’m at right now. Any additional advise welcomed!

        July 5, 2016 at 11:49 pm #39655
        wiscoboater
        Participant

          Also Don, I pulled the flywheel today to inspect for condition. Nothing was melted, looks really clean. PM me your phone number and I can text you the pictures of everything under the flywheel. I can’t seem to load photos from my phone on to the site boards.

          Thanks,
          Jeff

          July 6, 2016 at 2:48 am #39672
          fleetwin
          Participant

            US Member

            Go with Dan’s advice, try to get the engine running first. I saw the rubbed charge coil, don’t know how that could have happened. Try checking the charge coil resistance. I will try to find the spec, somewhere around 600 ohms I believe. Check the resistance of the sensors as well, should be around 40 ohms. Check sensor resistance between sensor #1&#3, then between #2&#4. I’m thinking the other sensor will kick in once the engine is running as well….
            That charge coil is the original style, plan on replacing it in the future if you are keeping the engine.
            For now, it is best to get the engine running and evaluate it that way.

            July 7, 2016 at 1:09 am #39759
            wiscoboater
            Participant

              I swapped in a good new style stator from my 115 today. The motor fired right up with spark on all 4 cylinders. Seems to idle nice, no hiccups. Going to replace the impeller and give her a test run on Saturday. Fingers crossed it works as well as it did on the muffs. Thank you Don and Dan! I’ll report back with results.

              July 7, 2016 at 1:28 am #39762
              fleetwin
              Participant

                US Member

                Cool, I’m glad it is working out without spending big bucks…Remember, this is a high compression engine, I would go heavy on the oil and use premium fuel….Make sure it is propped right and spins up a minimum of 5500RPM at WOT. Once everything is worked out, you will want to pull those carbs down to inspect the high speed jets. If it were mine, I would increase jet size by .002" as well….

                July 7, 2016 at 1:48 am #39764
                vintin
                Participant

                  If I remember correctly gentlemen I’ve read where there was a later service bulletin that suggested less maximum spark advance than when this motor was introduced. I don’t have the specs as hand. Something about preserving pistons. Sound familiar? I’ve got two of these motors on stands out in the shop so I have more than a passing interest. Thanks for the great info.

                  July 7, 2016 at 2:03 am #39766
                  wiscoboater
                  Participant

                    I’ve got 3 props to try on it. A 14 3/4 X 17, 14 3/4 X 19 and a 14 3/4 X 21. I don’t have a tach in the boat at this time. I’m hoping when I see Dan at Tomahawk he can give me the low down on wiring a tach and installing a lanyard style safety kill switch. I’ll feel alot better running this rig with a better kill switch then just the key. It’s a 15′ Glastron GT 150. Should scream with a properly running 135.

                    July 7, 2016 at 2:18 am #39767
                    fleetwin
                    Participant

                      US Member

                      Perfect boat for that engine!

                      July 7, 2016 at 2:25 pm #39794
                      wiscoboater
                      Participant

                        Vintin, If you can find that info please post it. I would be very interested in that.

                        Thanks,
                        Jeff

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