How to check a used engine?

ferryden · 07 March 2011, 20:12

What are the key points I should go through when checking an outboard being sold privately?...

Obviously check it works, no funny noises and no excessive fumes... check for tell tale flow...

But what else could I spot without taking an experienced mechanic along?

Thanks!

Steve_B · 07 March 2011, 20:24

Ask Biff, he seems to know a good 'un ..........

Nasher · 07 March 2011, 20:25

Take the plugs out and make sure you've compression on all cylinders by sticking your thumb over the hole whilst somebody pulls it over slowly.

Eh Biff

Nasher.

Nos4r2 · 07 March 2011, 22:09

Quote:

Originally Posted by Nasher

Take the plugs out and make sure you've compression on all cylinders by sticking your thumb over the hole whilst somebody pulls it over slowly.

Eh Biff

Nasher.

I wouldn't rely on that. A thumb can't tell the difference between 80psi compression (ie knackered) and 120psi (OK). A compression tester is a good idea.

Wiggle the transom clamp. Any free play back and forwards is bad.

Still better to take an experienced mechanic along though.

nugent · 08 March 2011, 05:54

defo do a comp test i would never buy an engine with out a gauge at hand,

biffer · 08 March 2011, 07:44

i've worked out a way, when you go to look at it, this is now my revised way of checking an out board.
ask him if it runs ok and has it any faults, stop him before he answers and look him straight in the eyes and tell him, if you lie to me i'm going to bbq your daughter and rape your dog, after that i'm going to send my girlfriend round to nag you.
failing that i'll have a look to see if it's got all the pistons

9D280 · 08 March 2011, 08:06

And if it passes all those tests, first thing when you get it home - check the locknut on the spark advance stop is fully tightened......

If it's a premix 2- stroke and looks like there's an oil slick out the exahaust, turn the conversation to how the seller mixes the oil. I bought an engine once where just putting it in the water would have given the environment agency heart failure because of trhe oil dripping out the prop hub. One twist of the conversation and after confirming he accurately measured out the oil, then "added an extra big gloop to be sure". Half an our on actual 50:1 and it ran much better!

So, with premix an oil slick is not something to worry about. If, however a 2-st oil injection machine has an oil slick I'd be a bit suspicious.

Also take the lid off & check wiring connectors for corrosion etc.