Johnson 120HP

knuuttila

Cadet
Joined
Jul 21, 2003
Messages
23
Can anyone help.<br /><br />I,m considering buying a Johnson 120HP V4 engine secondhand. My mechanic friend tells me it is a very thirsty engine and unreliable. Has anyone any tips on this engine? Also, is there a web site that I can look at that gives me the production dates of johnson engines as he says it,s 5 years old. Again my mechanic says it must be at least 10 years old.<br /><br />Finally, I have a Johnson 235HP. A great motor but the drive shaft splines have worn out in the crankshaft.Is this the end or can the engine be repaired. Any help would be greatly appreciated.<br /><br />Rgs<br /><br />Brian
 

Spidybot

Lieutenant Commander
Joined
Apr 4, 2002
Messages
1,734
Re: Johnson 120HP

The Swedish site www.marinshopen.se link ModellGuide is informative.<br /><br />As with any other motor, a well kept and well serviced unit is extremely reliable.<br /><br />Thirsty? Depends on how it's used. Flat out all day will make the fuel pour, but that goes for all. Alright, some are better, but the V4 ain't no worse than the average.<br /><br />Depending on which splines are worn (crank or shaft?), replacing it is either a matter of removing the lower unit and replacing the shaft :) or the crank :(
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Johnson 120HP

The V4 loopers are great engines. They develop quite a lot of torque. Set up wrong they can, as any engine can, burn a lot of fuel. I doubt that its only 5 years old. The last year for a 120 was 1994 I believe. In 1995 the V4 loopers were 130's. Get the model number. Also look at the tab sticking up on the head gasket and tell us what it looks like.<br /><br />As for the splines, yes the crank splines can be changed. If its the driveshaft splines just change the shaft.<br /><br />Good luck!
 

93bronco

Ensign
Joined
Nov 11, 2001
Messages
962
Re: Johnson 120HP

120/125/130/140hp loopvee motors are great!!!!!!!<br />easy to work on, basic skills needed & manuals <omc>.<br />the only problems i see is<br />1- an outboard shop that doesnt know how to work on them.<br />2- they are a little heavier.<br />-<br />the 1992 120 i bought, turned out to be a <br />1988 140 w/120 trim.<br />i put it on my 1802 walk around Trophy, no problem getting on plain with that motor.<br />handled great. shoty mech work put it down.<br /><br />have fun.
 
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