Plugs 65 HP Johnson, 1972

[jay_merrill]

Re: Plugs 65 HP Johnson, 1972

Any chance that the idle is set too low?

Also, put an inductive timimg light on the spark plug wires, one at a time. This might reveal a cylinder that is not getting "fire."

 

[Leont]

Re: Plugs 65 HP Johnson, 1972

Thanks. Don't have a timing light but have ordered a cheap tester but I don't think it will give intensity only that I am getting fire. I pulled the plug wires back off each plug slightly and appears I am getting fire. I don't have a tach so I really can't say where the idle is set, I did, however, increased the RPMs slightly with the throttle and put it into gear with no help, died. Need to check the rectifier I think but I still am leaning more to the carb since I don't know how long it sat idle. These don't have a fuel pump, per se from what I am reading. Just the bulb to get it started. I have cleaned the fuel filter and replaced the bulb and connectors with the fuel line from the tank as one unit. Will order the carb. kits and do that. Will take any other thoughts and get back with progress. Thanks again. Leont

 

[Leont]

Re: Plugs 65 HP Johnson, 1972

Haven't had time to rebuild the carbs yet but when I was trying to adjust the low speed idle by the manual I could only get a response from the middle carb. Moving the needle in and out changed the RPM. There was no response on the upper or lower cards when I screwed the needle in or out?? Could that just be they need to be rebuilt?
Thanks, Leont

 

[Leont]

Re: Plugs 65 HP Johnson, 1972

I finally got a spark tester and checked the spark. No. one has no fire. Had another coil and tried it on it with no success (not sure how to verify if the coil is good or if it is in the power pack. May have to take it to someone at this point but I have certainly learned a lot! I suppose it could possibly be a bad plug, although they are all new ones. Will keep you informed. Thanks, Leont

 

[jay_merrill]

Re: Plugs 65 HP Johnson, 1972

If you used a spark tester and didn't see signs of spark, the plug probably isn't the problem. Also, unless you know for sure that the spare coil that you hooked up is good, using it as a test won't tell you anything for sure. Although its a bit more work, what I usually do is to swap the coil with another from the engine that is known to be good. If the problem remains at the same cylinder, its not a coil problem, while if it moves to whever the #1 coil was placed, it probably is.

A bad powerpack could give you a problem on one cylinder, but so could a bad sensor coil in the timer base. From looking at the photo of your powerhead, you have the original, metal timer base. That makes the possibility of a bad sensor more probable.

Try this test on the sensor coils.


CHECKING SENSOR COIL

a. Disconnect sensor leads from power pack terminals #8, #9, #10 and #11, common lead. Connect ohmmeter (LO ohms scale) to each sensor coil lead (white with black stripe). Connect other lead to the common lead (black with white satripe), meter should read 8.5 ohms plus or minus 1.0 ohm.

b. With sensor leads still disconnected from power pack, connect ohmmeter (HI ohms scale) alternately between each sensor and ground. Infinity reading on each sensor indicates good sensor. Zero reading indicates leads or sensor coil is shorted to ground and should be replaced.

c. The sensor coil and timer base are serviced as a unit.


While you are doing this, you may as well test the stator (charge coils) too. Follow this instruction.


CHECKING CHARGE COIL

a. Disconnect charge coil lead. Connect ohmmeter (HI ohms scale) to charge coil lead (brown) from power pack terminal #4 and brown/orange lead from terminal #5. Meter should read 900 ohms plus or minus 30 ohms.

b. Check for broken leads.

c. Charge coils are part of staor and can not be serviced separately.


If you get a bad reading on the #1 sensor coil, that will coincide with the lack of spark on the #1 coil, and you can be pretty sure what the problem is. You may also get out of tolerence readings on the other sensor coils.

If the timer base is OK across the board, the power pack becomes suspect.

You will probably find the stator to be OK, because they usually are not the culprit, when only one cylinder's ignition system is having a problem.

 

[Leont]

Re: Plugs 65 HP Johnson, 1972

Finally got back to the boat. Time and money stalled progress. It was the power pack. Now have fire on all three cylinders and have an extra coil, (good advice on those, should have deduced that myself) they were all good. Still have a lot of smoke but haven't had time to take it to the lake, could be fuel mix or just need to have carb. adjusted and ran for a bit. Have only had it in a tub. Have to work this weekend will try next week to get it in the lake. Thanks to all. Have a good 4th of July and Pray for our Troops and Our Country! Leont

 

[jay_merrill]

Re: Plugs 65 HP Johnson, 1972

Excess smoke may be as simple as the low speed jets being set too rich.