1972 18HP Evinrude Running Rough

[billmc47]

Motor has not been smooth running since I first got it started. I have fixed the steering bracket, and rebuilt the carb. we took the fly wheel off and checked the points. didn't look bad. Seems to have less power since the carb was rebuilt. Wondering where to go from here. Any advice.
BillMc

 

[Solittle]

Re: 1972 18HP Evinrude Running Rough

What troubleshooting have you done? - compression? Spark? Squirted some pre-mix into the carb throat when running? Dis you completely disassembled th carb? Soak it overnight? Use high pressure air? Install a new kit?? Adjust?

 

[vintage boat junky]

Re: 1972 18HP Evinrude Running Rough

Usually the screw on the carb has to be 1 1/4 turns from taught. Also, it may be related to the gas/oil mixture if nothing else.

 

[samo_ott]

Re: 1972 18HP Evinrude Running Rough

Are the coils good? Are you sure you got all the passages clean in the carb? Does it run rough at idle or wot or always? Did you test the compression although that's unlikely it.

 

[billmc47]

Re: 1972 18HP Evinrude Running Rough

Son rebuilt the carb so I can't answer any questions there. I did not do a compression check but it takes allot from me at 260 pounds to pull the rope. So son's the old motor has great compression. Played with the lean rich mixture setting today, have it running a little smoother. When on the water, it is running better, seems to be a hesitation between idle and full speed. Overall running smoother. I mixed the gas 50 to 1 used quicksilver. Easy way for me to say it is that when you step on the gas it hasitates. The lean mixture arm is broken so it is hard to make any adjustments on the water. Overall a successful day with the boat.
BillMc

 

[whywhyzed]

Re: 1972 18HP Evinrude Running Rough

......

 

[tashasdaddy]

Re: 1972 18HP Evinrude Running Rough

http://forums.iboats.com/showthread.php?t=167352