Johnson 40 h.p.

Johnson 40 h.p.

I have Johnson 40h.p (1961 model) which will not start has been in storage approx. six years. Have<br />cleaned engine replace plugs,points,had starter checked. Still will not fire,no spark on top cylinder. using Clymers shop manual EVINRUDE/JOHNSON (1956-1972)to do repairs. any help appreciated.

Re: Johnson 40 h.p.

Re: Johnson 40 h.p.

G'Day, A.J.M.<br /><br />You have at least 2 problems.<br /><br />1. No spark on top cylinder. Your '61 engine uses a dual magneto. One is not working. Points and condensors are cheap enough that I would replace both. Then I would compare resistance readings between the working and dead mags to identify the fault.<br /><br />2. No start. If your carb was supplying an adequate fuel/air mix the engine would at least try to start on the cylinder that has spark. Spray some fuel mix (24:1) into the carb and try her. If she sputters you have a bad fuel system.<br /><br />Overhaul the carb and the fuel pump. Check the tank vent, pickup, fuel line and primer bulb.<br /><br />While you are working on her, change the impeller and lower end grease.<br /><br />Let us know what you find.<br /><br />Good luck.

Re: Johnson 40 h.p.

Re: Johnson 40 h.p.

In addition to JB's excellent advice:<br /><br />The top cylinder can be grounded (killed) by the vacuum cutoff switch, which could be frozen. Try removing the wires from that switch and seeing if you get spark.

Re: Johnson 40 h.p.

Re: Johnson 40 h.p.

I have followed the good advice give to me, but cannot get top cylinder to fire. Have changed plugs, cleaned rebuilt carby and fuel pump. Lower cylinder fired but running rough. Local repairs say motor too old too worry about. But I would like to try and restore.

Re: Johnson 40 h.p.

Re: Johnson 40 h.p.

Hi Ajm<br /> Sound as if you might have a bad coil. Check the vacuume cut-out as previously mentioned. Then swap one coil for the other to prove bad. replace bad coil. This should get you going. If not, we'll come up with something else to try.

Re: Johnson 40 h.p.

Re: Johnson 40 h.p.

HI. GUYS I AM STILL HAVING TROUBLE /HAVE NOW TRIED TO DO ALL ADVICE/ SWAPPED COILS PROBLEM STILL THE SAME/ TESTED WITH MULTIMETER<br />READINGS LOWER 1.3 UPPER 0.9 WHAT AM I DOING WRONG

Re: Johnson 40 h.p.

Re: Johnson 40 h.p.

amj,<br /><br />It still sounds like your "Kill" switch is stuck or shorted to ground. However, if you've proven that this is not the problem, then,....<br />Have only seen this once BUT,....<br />Swap the points from one side to the other.<br />I once put in a set of point that was shorted. <br />DROVE ME CRAZY till I found the NEW points to be the problem.<br /><br />Good Luck<br />HAVE FUN!<br /><br />P.S. If you decide to give up on her, please let me know. I love these ol' motors & may we can werk sumthin' out.

Re: Johnson 40 h.p.

Re: Johnson 40 h.p.

AJM..... In addition to the excellent advice you've already recieved, I'll add the following.<br /><br />The coil & points closest to the carburetor would be the top cylinder coil etc. Something you might want to know.<br /><br />The points should be set at .020, and set when the flywheel key is aligned with the fiber rubbing portion of the points. Many times the new points will look clean, but may be fouled slightly with oil. Clean the points with acetone if needed.<br /><br />The coils must be installed properly. Look at the top edge of the aluminum plate that they attach to. Notice that there is a slight bevel to that top edge . The vertical edge of the metal portion of the coil (yoke) must be aligned with the top inside edge of that bevel for proper operation.<br /><br />If you fine no faulty components, the spark plug wire may be shorting out to the bottom of the armature plate (the plate the coils etc are attached to).<br /><br />When all is well, with the s/plugs removed, the spark should jump a 1/4" gap on that model engine.