You inboard chaps

[Bigplumbs]

Well From Mallorca I have been on the phone to 2 boatyards in Norfolk and I will be viewing 2 boats on Tuesday. All I know about is 2 stroke outboards. All you chaps with inboards and particularly mercruiser scan you tell me what I need to look out for on older mercruisers. Any info greatly appreciated

Thanks

Dennis

[Xboatboyx]

Service history is important, check when the out drive was last off, gimbal bearing replaced, impellers, manifolds etc. Older carbed Mercruisers can get blocked up especially if its been on the river most of its life so have a sea trial and really open it up.

[betty boop]

I guess you're looking for something bigger than my 3.0l inboard so would only say the same as James above. The 3.0l has its own issues, Alpha 1 leg my only experience of failures is the minor seals. Speedo seal is common to fail (although mine hasn't in 10 yrs) my lower leg vertical drive seal burst a few years and caused a ball ache to flush out sludge but was simple to fix. I'd say drain off some drive build from the top vent and bottom filler for water ingress sludge. if its 2005+ it should have a filler bottle and sometime water does rise into the bottle. but they should be OK if leg is taken off and split in 2 for service, mines 2 years+ as its not used much but yearly is the official impeller change rate. Anodes in the shaft housing are expensive to get out I believe and should all be checked.

We'll be in the broads over the weekend but guess that won't help you if wanted a look round/chat.

[Bigplumbs]

I will still be in Mallorca at the weekend but that was a very kind offer

[Ianfs]

Try not to read this on a phone!
If you are not good with Inboards and Stern Drive's it certainly can be a bit daunting and I know exactly where you are with this. Even if you are ok with them, there are always hidden bits and pieces which can catch you out.

Agree 100% with James, a Service History is your first step and BB has given some good tips too.

Main dealer servicing is good but you also get the anally retentive owners who has over serviced it, i.e. impeller changed every year without fail, even though that is in the schedule. These are the sort of things you'll find out if you are able to talk to the owner.

I suspect you'll get either,
1/ Owner who knows nothing mechanically but likes to be safe......I know nothing about engines I leave it to my engineer, in which case they'll be records of invoices etc.,
or 2/ Anally Retentive .....You'll get a never ending list of all the things he/she found wrong with it in the first place and how it was fixed and what they did over the last Winter, down to the choice between Synthetic and Semi Synthetic oil in this year of engine etc. etc., or finally you might get,
3/ The one to get an Engineer in to look it over...... Yes it has been serviced in 2013, "what sort of service?" I don't know my mate did it! No invoices or paperwork!! Also be careful to ask questions if someone says its been fully overhauled, this gets bandied around a lot, then you find it hasn't had exhausts changed.

Most older boats sold, will need something doing in the first year. The sort of engines you're looking at are either a V6 4.3 or a V8 5.0 or 5.7 it's important to know which are the expensive items to replace. Apart from establishing Service History, which I guess at this stage you have now done, look for records of Winterising. These engines are raw water cooled and if they haven't had anti freeze added during the Winterization process, during cold snaps water without anti freeze left in the engine can crack the block. Most of the time, if this has happened, it shows up with bad running on the sea trial.

Next to look at would be the Exhausts, Risers (not all engines have Risers, small blocks between manifolds and elbows) and Elbows. Depending on Fresh or Salt water these can last between 5-10yrs and longer in some cases. Costs vary but about £1k would cover most types and OM parts even more. Fitting is fairly simple if you have enough space but I'm guessing £5-800 ish from a marine mechanic. If these fail water will run back into the cylinders with catastrophic effect. As you can't see inside these, you might ask how you know if they are OK. Water flow is a good test, with the engine running if you can put your hand on top of the elbows and its hot, that's fine, if you can’t touch them, then they may be blocked. Also, if the owner has had the boat a few years and not changed them and they look old and rusty, that's a sign they may require replacement.

Moving to the stern there is a Transom Shield on the inside which takes the exhaust and various cables to the water, check for leaks here, in the bilges etc. The Shield is bolted to the Gimbal Housing which is on the outside, which holds the Stern Drive. Check the drive for looseness, it might move about a bit from side to side but shouldn't move up and down. If it does wriggle a bit have someone in the boat to check if it is only the tiller pin a bit loose, anything else in the Housing area can be expensive.

There are Bellows inside the housing, two of them are important, Drive Bellows (the big one) and Shift Bellows, very small, if these leak, worst case, they could sink the boat, not so bad but expensive, damage the Drive Shaft and Gimbal Housing and in the case of the shift bellows leak into the boat and replace the cable. The 3rd is the exhaust bellows if this leaks it will only make a noise, but when changing them it is usual to do this one as well. The Drive Bellows basically keeps the drive shaft and Gimbal bearing dry and the Shift Bellows covers the Gear Shift Cable and acts like a seal where the cable goes through the Transom. By the way, Stern Drives stored with the leg up can be prone to stretching the bellows shortening their life, but if the boat is on dry land lifting the leg to the trailering position, fully up, gives you a bit more room to inspect them and take a torch as well.

Drive oil is a good indication for a leaking seal in the drive. As BB said, later boats have a header bottle to top up drive oil, emulsiphied oil will show as milky. If it doesn’t have the bottle, the only way to check the gear oil is to let some out and look at it. Taking Stern Drives apart can be expensive. If the boat is in the water a film of oil on the surface next to the drive is also an indication that a seal may be leaking.

Impeller and Impeller housing changes should have already been covered with history checks.

Lastly if it cannot be checked if the Drive has never been off, getting it out can be a real pain. Drive could be rusted in the engine, Gimbal Bearing (Oh that’s a bearing about 10cm which sits in a case in the Housing and supports the Drive shaft through the transom). If you take a sea trial, any grumbling noise from the stern whilst running indicates either a worn Gimbal Bearing or Drive UJ’s. By turning the steering to full lock both ways the noise will increase if it is the Gimbal Bearing. Not expensive if you do it yourself but a few hundred quid by a mechanic.

Pictures are always a help too.
Hope this helps a bit.

[_Ed_]

^^ Very useful post that. That should become an inboard buyers guide or something

[mlines]

Also for reference.

Mark, the previous owner had our V8 boat fully serviced with Gimbal bearing at the start of the year in which we bought it. We did an interim service at the start of this year so following Mercruiser guidelines we are due a very full service at this year end.

We have been quoted £900 for the work, including travel to our marina, so this is a budget to set for a boat where you need a full service. This includes impellor change (under the engine!), Gimbal bearing and removing the risers and a video borescope inspection of the manifold internals to determine the corrosion position. As the boat has spent a significant element of its life in fresh water we are going doing this route rather than manifold replacement at this age as we feel there is a good chance they are in good internal condition.

Martin

[shibbs]

I first read this post a few days ago but didn't have time to reply at the time. I went through the same process as I was switching from Volvo (which I knew) to mercruiser ( which I had no idea).
Luckily at the time (on the old forum) I got lots of likewise advice and was going to pass on the limited knowledge that I learnt, but tbh, that write up from Ian literally says it all!!
The only thing I could add, is that when I had my test run on mine I noticed some oil around the back of the boat when it was sat on the berth and likewise a trail when it was pulled out on its trailer.
I thought the worst at this point think I it was drive leg but it turned out one of the braided hoses leading to the tilt Rams was leaking slightly. A simple fix luckily, it was just loose after its service.

[Bigplumbs]

Many thank for all this very helpfull advice. It does all sound a little scary.

And to think all my wife has been looking are the cushions lol : )

[shibbs]

It does all sound a little scary.

Yes but oh so worth it!!
And my wife did exactly the same thing...