I am not a 2 stroke/outboard guy all that much, but am a 69 YO retired ASE Master technician that made a life with internal combustion engines.. Just this past october I rebuilt the engine in my Grand Cherokee in frame, in the driveway, on my back, new pistons and all, so I have some "residual" ability left from my work years... I have a tired 1996 Johnson 30 HP 2 stroke.. 90 PSI each cyl... It should have more like 120 psi. It starts[hard], and still runs pretty strong at mid and full throttle, but idles poorly and sneezes like crazy at low/idle speed.. Sure signs of low compression.. No rod/piston noise that I can hear.. I am thinking that in this case a set of rings and a cyl honing as well as new crank seals should get the compression up to where this engine runs better.. I am just not in a position to spend $1500 or so on a 20 YO engine that might have 500 hours on it, and is almost as tired as mine.. I keep buying used engines, and after a year or two of light use, they always seems to go bad.. So I just want to try and rebuild what I already have,.. Its pretty clean looking, good lower unit, electric start, remote steer etc.. Rings and gasket set as well as the factory manual, probably less than around 150-175... Just looking for any thoughts, insight, helpful advice. "tech support" from those that have done similar, or those that are serious outboard motor guys with more experience than I have.. any suggestions would be well appreciated... bob
Did that last year.. Didn't look too awful bad.. I put a new head gasket in as well at that time,, and ran the engine several times.. It starts hard, and runs crappy at idle and low speed, pretty good at mid range and full throttle.. The fact that the engine has 90 PSI each cyl should indicate that the bores are are pretty decent, no??. I know 90 PSI is NOT good, but if there was major damage or scoring, wouldn't the compression be a lot lower?... I was hoping 90 psi was enough to indicate that a cyl hone, new rings ,new crank seals, would get me close to where the engine wants to be, or am I being really naive'??... bob
There is no reason for one of these engines to go bad after 3 seasons of light use.----They are very well built.---People destroy them with improper operation and abuse.
There is no reason for one of these engines to go bad after 3 seasons of light use.----They are very well built.---People destroy them with improper operation and abuse.
I think you might have misunderstood my complaint.. I think the reason I am on my 3rd 30 HP OMC in the past 6 years is because by the time I get them, they are already worn out.. I need to be more diligent, but I am a VERY trusting soul that believes that most people don't take advantage of unsuspecting types like myself.. Next time, I run the engine at length, and take compression tests before and after it runs.. I have been burnt WAY too many times, over too many years,because I trusted the words "its a good runner"...
