Johnson 70 hp 3 cyl died & won't start

[geminisuz]

Have been running this motor all summer w/no probs. Starts 1st turn of the key every time. Went out Sat, ran all day - start/stop fine. Motor died just before we were going to shut it off at anchor. Started again immed., ran 5 secs, then died again and will NOT start. Cranks fine, just won't fire. I am an amateur. Any thought on what to check first?

 

[zantz]

Re: Johnson 70 hp 3 cyl died & won't start

Welcome to Iboats!<br /><br />Gas, Spark, Compression... The 3 things needed to make a motor run... Basically.<br /><br />Like my Dad used to say<br />1. Does it have gas and is the vent open? (the vent always got me when I was young)<br />2. Do the spark plugs have spark?<br />3. What is the compression readings?<br /><br />The first 2 are easy to check with minimal tools. The 3rd requires a compression gague. Which you should get if you plan on being a DIY'er (Do-it Your selfer).<br /><br />If it has gas in the tank, the pump bulb is firm, and the spark plugs have spark, try squirting a little pre-mix in the carbs to see if she'll fire up a little. Then go from there.

 

[JB]

Re: Johnson 70 hp 3 cyl died & won't start

Hi, Gensuz.<br /><br />Welcome to iboats. <br /><br />Check out the "Outboard wont start" post in the Engine FAQ forum. It will guide you to the area of the failure.<br /><br />Good luck, and let us know what you find.

 

[geminisuz]

Re: Johnson 70 hp 3 cyl died & won't start

Ok - got it fixed. Took a master to do it though - my Dad - who knows everything there is to know about everything. He had it pinned within ten minutes of taking the cover off. It was a bad ignition switch. It had water in it and was shorting at the power pack. We tested for spark and had none, got to the power pack and there were readings coming in, but nothing going out to coils. He realized No. 6 wire (from the key switch) was bad. When we removed it, the motor fired right up, but we had to short it out to get it to quit. Traced the problem up to the switch itself, which had water in it when we took it out. All fixed & back on the water. Thanx so much for a great boating forum. Maybe this will help someone else.

 

[fireman57]

Re: Johnson 70 hp 3 cyl died & won't start

Sounds like your Dad needs to join this forum. Glad it worked out.