Used outboard inspection...

[hambone]

I'll be getting a compression test done soon and I want to make sure that I fully understand the results. Good compression means that all the pressure readings are within 10-15% span? What about the pressure average, is there a min/max that the average reading should fall within? and if so, is this something you would find in the owners manual?

What are some of the most important things to check in general when inspecting a used outboard. The bigger the checklist I have the better.

I'm looking at a 2004 Honda 135EFI (308 hours)... feel free to add any comments about this motor if youve had experience running one. So far my internet searches havent raised any alarms..

Thanks for any input.

 

[spring time]

pull the leg oil top plug to see if milky oil or clean oil

 

[scott craven]

I'm not a mechanic but would be looking for 200-225 per cylinder with a pressure drop variable
of no more than 5% per cylinder

 

[Fish Assassin]

I'd guess 150-180 no less then 10%.

 

[jeffywestcoast]

I would guess...wait no I wouldn't... I'd get a certified marine mech to look it over.. 100 bucks now could save you thousands down the road.

 

[hambone]

I would guess...wait no I wouldn't... I'd get a certified marine mech to look it over.. 100 bucks now could save you thousands down the road.

Yep, the motor is at a dealership, so I will definitely be getting it checked by a mechanic. But I still need to be able to understand the numbers.

 

[spring fever]

pull the leg oil top plug to see if milky oil or clean oil

I may be wrong and might learn something but I thought you pulled the bottom plug-water should separate to the bottom-also if milky you see it -sometimes when selling guys just give a little top=up of clean oil. The bottom plug also has the magnet to see metal particles or chunks. _NO?

 

[profisher]

Spring Fever you beat me to it. Yep leave the top plug in and pull the bottom one. Any unmixed water will come out first, then check color of oil and check the magnet for larger metal slivers. Have it scoped and get a print out from the computer. You should get some details on important data like if the motor has been over reved and for how many hours. Will give you some sense as to how the previous owner looked after it or abused it.

 

[KV1]

I don't want to sound stupid but I would look at corrosion for sure. If any part of the engine externally looks like a cauliflower (white powdery chunks) it would tell you how much the owner cared. Any change in paint color in the bottom of the skeg or leg would tell you they smoked something and either got it welded and covered it up or got cracked with water in the leg and then froze and was covered up.

Obviously spark plugs will tell you a wealth of details too but if they are sharp they would have changed these as well as the leg oil. People are very crafty when they sell used stuff have found this first hand. Myself I keep a maintenance record on all my stuff so if I ever go to sell it at least it shows that I cared. If zincs are almost gone or non existent it will also be an indicator or even a chip or chunk out of the prop. Dipstick on a four stroke but like I said they might have changed it. Compression although a good test to do can also be "fudged". Unfortunately with used there is always that chance of being burned that's why its buyer beware.

 

[Doug]

If they are doing a compression test. Get them to do a wet and dry test.

On any cylinder which come up lower than exspected, add a few tablespoons
of oil into the cylinder plug hole, perform the compression test again. If the compression comes up
the rings are thin, if the compression stays the same the valve guides are worm.

 

[Doug]

if it is a dealer get a one year warranty written into the deal. It might cost a little but you will have something to fall back on if something goes wrong .

 

[Fishin'Zinn]

Good engine choice. You basically want to see constancy throughout the cylinders with a compression test. Yes, you can do the oil trick to see if the rings are being worn, however, with 300 Hours, if it's been maintained, you should be having no serious problems needing to be fixed with a Honda...

 

[NootkaSounder]

Compression test
Engine oil
Leg oil
check for bent shaft
prop/leg wear can tell if they ever hit or ran into anytthing

 

[hambone]

Thanks guys, appreciate the responses.