73 Evinrude Yactwin Starting Probs

[rather_be_boatin]

I have a 73 Evinrude 4hp Yachtwin (2 cyl). I've replaced the water pump, points, and re-built/cleaned the carb. It is a royal pain in the .... to get started. Once it starts it runs well but does not want to idle. Does anyone have any advice?

 

[F_R]

Re: 73 Evinrude Yactwin Starting Probs

So, while you were in there replacing the points, how did the coils look? What is the compression? Has the motor ever ran hot?

 

[rather_be_boatin]

Re: 73 Evinrude Yactwin Starting Probs

Coils appeared brand new. Spark is strong. Not sure how to tell if she runs hot or if she has ever overheated. When running I cannot keep my hand on the cyl. head or spark plug, not sure if thats normal or not. (probablly above 105F) She does not smoke any more than I'd expect, actually she hardly smokes at all. Also forgot to mention both plugs come out looking even combustion, slight chocolate like you'd expect from a 2 stroke. (50:1) Not sure about compression, will have to get back to you. If bad compression, are rings hard to change in this unit? Also forgot to mention I did a head gaskt too because of low compression and clean plug on lower cylinder. Seemed to cure it.

 

[tashasdaddy]

Re: 73 Evinrude Yactwin Starting Probs

are you using the choke when starting. is it closing completely.

 

[rather_be_boatin]

Re: 73 Evinrude Yactwin Starting Probs

Compression is:

w/o shot of oil / with shot of oil

Upper Cyl.-80# / 90#
Lwr. Cyl. -75# / 80#

Not sure if this is normal or not.

 

[rather_be_boatin]

Re: 73 Evinrude Yactwin Starting Probs

Yes, choke is on and linkage works perfectly, butterfly valve goes full closed. Right after it starts I usually have to go to 1/2 choke after about 30 secs. to keep her running.

 

[Scaaty]

Re: 73 Evinrude Yactwin Starting Probs

Try raising the float fuel level...had a 5 1/2 that was a bear to start...float set perfect...raised it some more and its a second pull now..

 

[tashasdaddy]

Re: 73 Evinrude Yactwin Starting Probs

are you pumping the primer bulb until it is hard? not just a couple of pumps.

 

[rather_be_boatin]

Re: 73 Evinrude Yactwin Starting Probs

Yes, pumping primer till hard, always verify tank vent open. (after watching the tank implode one time and still ran... Oooops!) How do I adjust the float? Is there a micro-feshe link? I'm also guessing I should not use ether (starting fluid) because it will was cyl. walls and lose compression?

 

[tashasdaddy]

Re: 73 Evinrude Yactwin Starting Probs

you have to remove the carb, to set the float. use some premixed gas in a spray bottle, 86 the starting fluid. it's the best way to burn a hole in a piston.

 

[rather_be_boatin]

Re: 73 Evinrude Yactwin Starting Probs

Thanks, will try that. Does that compression sound right for that make/model, seems like most of the compressions I read about on here are over 100#?