74 evinrude 6 hp smokes and no top end power once warmed up

[markwil]

Hi there, I have a 74 evinrude model number 6402c c 73119. 6 hp. Last year I was having trouble and changed the fuel pump which fixed my woes for the summer. This year when I started it up after storage for the winter (with gas stabilizer)it would start after quite a few pulls but run rough at the top end. The plugs were black and very little spark so at the suggestion of a local shop I checked the coils and sure enough one was cracked. I have replaced the coils, points, condensers and plugs.After that it idled like a top and after just starting i can rev it up no problem. Once it warms up though it will still idle fine but there is no top end power and it smokes and runs rough. I have also cleaned the carb and installed a new carb kit.<br /> One thing that I did notice is that pulling the plugs out the top one is black and the bottom one is remaining white. Could I have blown the head gasket??

 

[sloopy]

Re: 74 evinrude 6 hp smokes and no top end power once warmed up

Have you adjusted the carb jets? It takes some tinkering and time but it should solve half of the problem. You may also need to decarb your engine. I do not know about the head gasket, but it would not hurt to replace it. <br /><br />P.S. do you have the correct plugs in?

 

[markwil]

Re: 74 evinrude 6 hp smokes and no top end power once warmed up

Thanks for the info. I do have the correct plugs in and as far as the jets are concerned there is an ajustment for the slow speed but the high speed I think are fixed.As far as decarbing the engine??? is that just a spray to put in and do you have to have it running ok at fast speed before you do that?

 

[markwil]

Re: 74 evinrude 6 hp smokes and no top end power once warmed up

I was also wondering if anybody knows of a good source for owners manuals for these engines?

 

[DJ]

Re: 74 evinrude 6 hp smokes and no top end power once warmed up

Owners manuals-no. Repair manuals-yes.<br /><br />Look here.<br /><br /> http://www.outboardrepairs.com/manuals/

 

[markwil]

Re: 74 evinrude 6 hp smokes and no top end power once warmed up

Thanks and repair manuals is what i was looking for. Just a slip of the fingers.<br />PS I've been doing some reading on past posts and saw a few articles on crank case gaskets and reed valves could these be my problem?