1977 evinrude 140 hp on a 1988 skeeter sf150

evin/skeet

Cadet
Joined
Apr 21, 2011
Messages
9
this motor will only turn 4200 rpms it seems a little cold natured at first sometimes motor shakes in excess like its missing other times it runs fine but will never turn more than 4200 rpms ive tried several props 21p down to 15p and the rpms have not changed checked compression and all 4 cyl were between 120 -125# the local marine mechanic looked at it and said probably the stator going bad any sugestions
 
D

DJ

Guest
Re: 1977 evinrude 140 hp on a 1988 skeeter sf150

1. Check compression on all four.

2. If OK, rebuild carb's.

3. Check spark on all four.

You can flip 2 & 3.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1977 evinrude 140 hp on a 1988 skeeter sf150

Have you removed the airbox cover to check to see if the carb butterflys are fully open (level) when the throttle handle is in full throttle position? Have you checked the max timing when at 4200 rpm on both #1 and #2 cyls? [That max timing should be rechecked once you get the engine to run at least 5000 rpm.] CDI electronics (on the web) has some excellent troubleshooting information on this electrical system. Page 35. They have spec stator voltages going to the power packs that should give you an indication of the health of that ignition system. It should give you an indication whether the stator is bad. The compression should be just fine.
 

evin/skeet

Cadet
Joined
Apr 21, 2011
Messages
9
Re: 1977 evinrude 140 hp on a 1988 skeeter sf150

thanks i will check the butterflys again but the mechanic said all was working properly and it had to be electrical
 
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