1974 evinrude fastwin wont IDLE!!!!!!

rocky25

Cadet
Joined
Apr 4, 2004
Messages
19
hey guys whats up? i have have 18 hp 1974 evinrude fastwin, and it wont idle worth a crap! when i have it at wot,it runs like a clock, but when it idles, it seems to sneeze and it eventually gets to the point where i try to rev it up, but that doesnt work, and then it just stalls. does anybody know the problem here? if so please help! thanks guys!!!<br /><br />PS. apparantly these outboards are notorious for this
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: 1974 evinrude fastwin wont IDLE!!!!!!

Dont know whats wrong with yours but every one I ever had idled great. Even when we started sticking a 70 hp carb on 'em.<br /><br />But they had clean carbs, good compression, good spark at the right time, the correct spark plugs, no air leaks and the sinc and link was correct.
 

joe_morgan

Seaman
Joined
Mar 25, 2004
Messages
51
Re: 1974 evinrude fastwin wont IDLE!!!!!!

Check what your butterfly is doing when you throttle down. It might be closing too far and choking the engine. How does it run when you start from cold. Does it idle smoothly ?
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: 1974 evinrude fastwin wont IDLE!!!!!!

Rocky... If you have compression, the proper spark, and correct s/plugs set properly, I'd suspect that the carburetor is fouled somewhat.<br /><br />If so, the cure would be to remove, clean, and rebuild it. After which, you can adjust it as follows.<br /><br />(Carburetor Adjustment - Single S/S Adjustable Needle Valve)<br />(J. Reeves)<br /><br />Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.<br /><br />Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.<br /> <br />Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting. <br /><br />When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
 

rocky25

Cadet
Joined
Apr 4, 2004
Messages
19
Re: 1974 evinrude fastwin wont IDLE!!!!!!

thanks for the help guys, i figured it was the carb, ive also noticed a hose running from the front of the block over to the intake side on the top cylinder, ive seen the this dischage some sort of air everytime the engine sneezes, what is this hoses purpose? thanks for the help guys
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: 1974 evinrude fastwin wont IDLE!!!!!!

I believe that tube directs puddled fuel in the intake manifold to the top cylinder intake for burning. If it were open to the atmosphere, the top cylinder would run lean from sucking air, causing it to sneeze.<br /><br />Perhaps that's your problem?
 
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