'85 Force 50 hp wont start

[showme]

Hello, <br /> I have an 1985 50 horse that started and ran fine first time out this spring, I had it idling for approx. 10 minutes and it died. Since then I put in new spark plugs, it started fine and ran a while and died. The plugs are "wet" when I check them, the engine backfires through the exhaust and does not start. Any ideas? This motor has served my purpose well as I fish small lakes and have no need for speed. If it would only run I would be grateful!

 

[JB]

Re: '85 Force 50 hp wont start

Howdy, Showme.<br /><br />Welcome to iboats. <br /><br />Sounds like a timing problem to me. Could be a sheared flywheel key, could be that when you changed the plugs you got the plug wires switched.<br /><br />If neither of those is the case, go to the Engine FAQ section and try the troubleshooting steps in "Outboard wont start".<br /><br />Good luck, and let us know what you find.

 

[showme]

Re: '85 Force 50 hp wont start

Thanks for the reply, I am sure the plug wires are not crossed as I checked the location in the beginning. As far as timing problem, the motor started fine with new plugs and fouled them, so I wouldnt think it would have started and ran so well after the change. I did have last summers gas in the tank when I first had a problem, but since then I have replaced it with fresh gas. I also took the bottom bowl off of the carb., everything looked clean. Could it be the old gasoline is still the culprit? I have the spark plugs out right now letting my cylinders "air dry" as somenone suggested in another thread. <br /> Thanks again

 

[eurolarva]

Re: '85 Force 50 hp wont start

Sounds like a sheared key to me as well. Did you test plugs for spartk? Ground the threads and watch in a dark area. Should be a blue spark not yellow. Do you have the correct plugs in the motor? Could be a gas issue but I doubt it. Typically backfire is caused by timing. Have you checked the piston TDC in respects to your timing marks. This would be an easy test to perform so you dont have to remove the flywheel.

 

[JB]

Re: '85 Force 50 hp wont start

What did you find when you did the troubleshooting, Showme?<br /><br />Wet plugs are not fouled. Plugs that wont make a spark are fouled.

 

[showme]

Re: '85 Force 50 hp wont start

I let my plugs and cylinders air dry for two days, checked to make sure plug wires were in correct position, cleaned my electrodes and took it to the water. It would try to fire but not run. It seems as if it is barely running when I let off of the key with a backfire now and then. It was firing enough that my cylinder head was hot to the touch when I felt it. I guess I will try to find a mechanic, the only close mechanic to me has enough merc. yamaha business that he told me he would not work on a Force.

 

[showme]

Re: '85 Force 50 hp wont start

No luck yet, the search is on for a mechanic.