'67 Evinrude Backfire on Start

[Lampwick]

Now I really don't know too much about this outboard I have. As far as I know it is a 1967 Evinrude 40hp. It has ran fine for the last couple of years. It needed new spark plus but when I put in the new ones it seems to Backfire during start when it turns over. <br /><br />Thanks in advance for anyone could help me with this problem since this little problem is really cutting into my fishing <br /><br />Thanks in advance.

 

[Goodoleboy]

Re: '67 Evinrude Backfire on Start

Welcome to the forum!<br /><br />Sounds like your timeing may be off. If your timeing lite jumps around all over the place, Then check for sheared fly wheel key.<br /><br />Good Luck!

 

[lark2004]

Re: '67 Evinrude Backfire on Start

What spark plugs did you put in?<br /><br />You want to use champion j6c or j4c (depends on running conditions, lots of high speed or lots of trolling) plugs gapped to .030" .

 

[Lampwick]

Re: '67 Evinrude Backfire on Start

Yeah, I put in my old spark plugs and it seemed to start up fine! I will go grab some of those Champions....thanks guys....this board is great I will be sure to add this to my regular net reading!<br /><br />Thanks

 

[byacey]

Re: '67 Evinrude Backfire on Start

I can't see plugs causing backfiring while starting, after running hot, maybe... Did you perhaps have the sparkplug wires on the wrong cylinders when you initially changed the plugs? The top one usually has a tag or mark on the wire.