buying a mercruiser 3.0 what to look for???

[gandk]

hi there im quite new to this and really could do with advise. im looking at a boat with a 3.0 mercruiser made in 1994 with an alfa 1 leg. Could any one please advise me what to look for on these? i know a bit about engine not a huge amount but reallycould do with some advise on what to look for when buying one of these. Especially any help with the stern drive as i have very little knowledge of these. are there any comen problems or how do i look for a bad one?? any help is much apriciated thanks in advance.

 

[glang308]

Re: buying a mercruiser 3.0 what to look for???

Howdy, and welcome to the site and the world of boating. A 3.0 and alpha one drive is a good combo and a good choice. Looking for obvious signs of damage or neglect is a good place to start. Trim up the motor and try to see and feel what you can of the bellows. There will be three of them and the rubber should feel thick and plyable without any holes. It being a 1994, the bellows should have been replaced by now, if not they will be due. The trim should operate smoothly and you shouldn't hear any gear noises as it is raised and lowered. If it has a trim gauge, make sure it works, if not it could be the gauge or the senders. Read a little on some of these blogs using alpha one as your keywords. There are a lot of great questions/answers that will help you with understanding how the drive works, and the maintenance required of the drives/engines. Hope this helped.

 

[Liquid_force]

Re: buying a mercruiser 3.0 what to look for???

Your experience level sounds similar to mine.
For one I'd never buy a boat w/o a test drive (unless it was an absolute giveaway)

Before it's running I'd check the engine compartment for any signs of fluid leaks. Fid the tilt/trim pump and look for any wetness there, PS, oil of course...then after you run it check again looking for any changes.

On the water -- does it start quickly, or need a lot of babying (carb issue?) -- if it's EFI I would expect it to fire right up.

Does it idle smooth, everything sound good?

Does it shift smoothly - fwd and rev.

I wouldn't take it easy on it during the test drive. I'd do a few idle to WOT starts. Listen to the motor, but more importantly listen for anything strange from the drive. I can tell you from experience that a little clunk/pop can lead to $1000+ for new gears.

Keep an eye on the temp gauge. High temp could be a sign of a bad/failing impeller which in my experience isn't THAT easy to replace on a merc.

Give it some good sharp turns to test the steering system stop to stop.

Once off the water I'd ask to see the lwr unit fluid by draining a little out - make sure there's no milkyness to it. You could go as far as pulling the drain plug (plug the drain hole with your free hand) and look for any signs of shavings on the magnet.

That seems like a pretty thorough once-over to me.

 

[BF]

Re: buying a mercruiser 3.0 what to look for???

ask about maintenance history and if possible, documentation for it being done. I just bought a 1990 sea ray with 3.0 and alpha 1.... It's in good shape and runs strong.. little use from previous owner and it shows. Having said that, owner was very straightforward and acknowledged that he changed engine and gear oil every fall, but beyond that, for the 5 years he owned it, the outdrive had never been off. That told me that U-joints had not been lube'd, and impeller had not been changed. Ditto what was said above, you definitely what to hear it run... if there's bearing whine or clacking/loud whirring from the U-joints you know where you'll be headed.

I could hear some gear noise, that I rightly assumed was the gimble bearing. So, I knew when buying the boat that I would pulling the drive and giving it a once over and catching up on maintenance before using it. If you're mechanically inclined, it's not bad to work on, but if you're not, then I/O's may not be your cup of tea. Shop costs for servicing a stern drive may surprise you. (and not in a good way) The drive needs to come off regularly (annually probably) to lube things properly, so either decide if you can live with doing that yourself, or call a shop to see what they charge for common things (e.g. gimble bearing replacement or U-joint lube).

So for me, it was new gimble bearing, new impeller (the old one was BAD), greased U-joints, aligned engine to drive... A couple hundred $$ for bearing/seals/water pump kit/gear lube/spark plugs... (that's parts cost only, I did it myself... I'd guess it would be a 4 digit bill to have it done here) I left the bellows alone (for now) as they seemed fine, but I plan to pull the drive again after August and re-inspect. I may do the bellows and replace the U-joints then.

 

[gandk]

Re: buying a mercruiser 3.0 what to look for???

this is all great stuff thanks so much for all your help, and so fast!! im looking at it tmrw so fingers crossed. anyone is more than welcome to add more things to check?? thanks

 

[gandk]

Re: buying a mercruiser 3.0 what to look for???

in relation tot eh u joints and gible bearing where are these? i assume there are behind the engine after the drive? does anyone have a pic or diagram? cheers so i know where to look listen? sorry maybe a stupid question i know and may be blindingly obvious when i see it but dont know that engine well at all. Also is there cam shaft inside the block or in the head? ie does it have a cam belt or push rod system?

 

[gandk]

Re: buying a mercruiser 3.0 what to look for???

ok i went to look at it and had a few problems, we started up the engine with the lower leg in a huge bucket of water, it seemed to run fine but the owner put it on slightly too higher revs for about 20 seconds before letting it idle in neutral for a while, in the bucket there seemd to be no water moving like i assumed there would be? the temp gauge when up slowly and kept going up until i asked him to shut it off as didn't want to get to hot. does the impellor suck up water from the bucket when idleing? i assumed it would suck up the inlets and warm water would come out the center fot he prop. Does this kick in when the engine gets hotter? be great if someone could help. the boat was used last 2 months ago and has video of it running at a good speed and said there was no problems then. am i being dumb? or is there a serious cooling problem? thanks