I have a 1998 Johnson 3 cylinder 35hp (model # j35PL3EE) that I purchased from the original owner mid-July 2006 along with a 17’ Bristol Skiff. The boat/motor had not been used for 18 months. The seller had told me that he had winterized and serviced the motor every year and never had any problems with it.
Before purchasing, I test drove the boat/motor for 30 minutes. For the first 15 minutes, it would cut out (shut off) when the RPM’s reached 4,000+ (essentially near full throttle.) During the second 15 minutes of my test drive, it would cut all power at full throttle, but not stop running, just drop to an idle. In both cases, a squeeze of the bulb would get the motor running back up again. The boat had not been used for about 18 months and I believed the owner that everything always worked well and that the problem is/was from sitting and that it needs a tune up. This seemed like a fuel issue to me.
Trouble shooting efforts to date:
After getting the boat home on a trailer, I was not able to start it. No kick or cough – nothing. It would crank and crank and crank but never fire. It gets fuel because when I pull a plug to inspect, it is soaked. There is no spark when I hold it against the cylinder head and crank the motor. (I’ve since heard that you can damage the motor but testing for spark this way) The only change I’ve made to the motor is replacing the plugs.
While my wife was turning the key and I was looking for spark, she said “I see a big spark on this side of the motor.” The spark she saw was coming from the bolt holding the power wire to the starter which was loose and sparks were jumping to the case when it was being turned over. Not sure if that’s relevant, but FYI.
I replaced the bilge pump switch because it did not work and cleaned all of the light contacts. (Unlrelated, but FYI)
The next day, I thought I would try again and turned the key and it fired right up. I turned it off and started it again. I did this a few more times and it sounded great. Then I tried it again and nothing. It would crank and crank and without firing at all. I tried a dozen times with 10 second cranking intervals and nothing. Came back two hours later and it still didn’t start. Half an hour after that it started on the first tap. Turned it off and on and it started everytime.
Next day, the gear on the starter would turn, but not rise up to engage with the fly wheel. I’m guessing this was simply a sticky gear or shaft on the starter and not the solenoid. Two hours later I turned the key and it started right away.
It seems to me that there are two problems:
One is the fuel issue that I experienced during the test drive which may go away with a little use or need a fuel filter. The gas has been replaced which could have caused the initial sluggishness. The second is ignition/electrical because there’s no spark but fuel is present.
The second is ignition. It goes from starting to not starting quickly and is entirely sporadically. It does not appear to be related to hot/cold motor or to flooding the engine. When it starts, it starts instantly. When it doesn’t, there’s nothing. No kick or cough or any sort of firing. Just cranking.
Any theories or suggestions? All comments are appreciated.