90's Johnson 120 outboard engine trouble

newtpw

Recruit
Joined
May 1, 2009
Messages
1
I have a johnons 120 outboard. I had trouble with it going last year. I went full throttle and it maxed out at 5 mph. any suggestions?
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 90's Johnson 120 outboard engine trouble

welcome to iboats, start at the basics, check compression and spark on all 4 cylinders, compression should be around 100 up, with in 10% of each other, spark should jump 1/2 inch. if all this is good, when were your carbs last cleaned and rebuilt, when was the last linc n sync done????? MODEL # or year of the motor please.

reads this please, http://forums.iboats.com/showthread.php?t=250879
 
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