v 6 Mercruiser 2004 Model.

[MEG-A-BITE]

Does anyone here have a boat with a mercruiser stern drive? I don’t know much about this motors. Im looking at a boat it’s a Whittley 630 Sea legend with a V6 Mercruiser Stern Drive 210 hp 4.3 Litre

1-whats the fuel usage like, are they economical? Any stats would be good.
2-performance can you tow a water skier, are the quick out the hole for bar crossings.
3-reliability are they reliable?


This particular motor has 238 hours on it and has not been used much at all over the past year.
Any other information would be good.

Thanks.

[snatchy]

Hi mate

i have one, slightly newer than the one you are looking at but same thing. mine is the 220hp rated 4.3L engine

1) Before i bought the engine i looked at heaps of boat test reports and various bits of info on fuel usage. The 220MPI uses the same amount of fuel as a similar sized four stroke outboard. from what i found 1.25L/Nm was about standard on a 21ft boat at cruise speed. Once fitted and running, that is exactly what i got. Rough weather brings that number up to 1.5 at worst, and maybe 1.6 offshore when you get caught out going on and off throttle and on and off plane - days when the forecast isn't quite correct and it is a bash to get home!! They are real world loaded offshore fuel figures. i am sure there are people who get better in their 21ft boat with a 250hp engine, but maybe not set up to go 40Nm offshore.

2) get a decent propeller and it is great acceleration. The standard 3 blade alloy Black max prop is woeful compared to a decent stainless 4 or 5 blade prop for acceleration. I haven't towed people with mine, but there is no reason for it to be a problem with 4.3 litres.

3) i think they are generally a reliable engine. Regular use, maintenance and fresh fuel will go a long way to keeping any engine reliable. Watch out for crap old fuel in the tank. The Gen 2 alpha leg (assuming that is what it is?) has a great reliability reputation. I had an alternator sieze and the water pressure sensor malfunction (minor issue). both common to newer mercruisers.

at ?? 6+ ?? years old, that motor will want to have the risers and or manifolds replaced soon if not already done. not sure if you are aware, but prices are very high for this (up to $400 each piece plus bits and labour) Fresh water cooled engines should be OK with the manifolds for a lot longer. Factor this in if there isn't any evidence of having them replaced recently.

Caution, rant follows;
Mercruisers get a real bashing because they are the same name of engines that were produced since the 1960's. They are guilty by associaton because 25 year old mercruiser engines are having problems, so a brand new mercruiser engine must also be unreliabe too, right? Same name so it must be the same thing! Who associates brown band Mercury outboards with a new Mercury outboard?.......No one... but that is effectively what happens when people mention mercruiser and start recounting how their old 165 mercruisers (kept in the salt on a mooring) were crap and had to be replaced so never buying a mercruiser again. There are a lot of one eyed (or outright blind) amateur commentators around so be aware of comments you read about mercruiser. In particular note the age of the relevant engine being criticised, how it was maintained and by whom over that long time period. nuff said! //rant over.

good luck and ask if you need more info

[The-easyrider]

Hey Megabite, I have to agree with Snatchy coments, I have the same motor as him in a 650 sea legend and use about 30 to 32 liters per hour running at 42 to 45 kph wit three to four up running out to hutchies and beyond. Have not had any big issues ,did have a bit of corrosion under the dizzy that caused a few head aches untill it was detected. We have towed the kids around on tubes and knee boards with plenty to spare so it would pull a skier no sweat. I run a mixture of props I like the four blade for grip in rough water and a little extra stern lift but my 3 blade ss fury gives me a better top end and slightly better economy and the old black max is good if you are planing to go into snagy areas as it wont matter when you bend it.
PS oh and great tourque and quick off the mark when needed while crossing the bar ;D

[sleepygreg]

good choice of boat/motor combination wayne. As above re stats on fuel usage. Have a couple of mates down south with similar rigs....and one with the same hull with an outboard....the ride in the mercruiser versions is a lot smoother than the outboard. The 140 and 210 mercruisers are very reliable donks when looked after (the 140's even when they arent looked after :S).

Cheers
Greg

[PADDLES]

yep, we've got an MPI one in a whittley 660 cruiser with a hi-five prop. chews around 25-30l/hr for a cruise of 20-22kn. great motor in my opinion, it's a pretty old design that's basically 6 cylinders of a 350 ci v8 so is fairly strong and reliable. our throttle bypass valve (for idle control, so you can still get it home with some revs) died which apparently is reasonably common but other than that it just goes. it doesn't seem to care about old fuel and just starts and runs every time. further to the comments above, the new dry joint style mercruisers are a step ahead of the older style motors, they've got good corrosion resistance and generally you can see when your risers need replacing because they will visibly leak, unlike the older ones where it just leaked straight into your motor.

[terryc]

I also have 2003 whittley cruiser 660 with the mercruiser 4.3 (220hp) all the power needed fuel usage as stated, the manifolds n risers seem to have max life of 4 yrs with salt water usage, I spent $2000 and self installed stainless manifolds riser combo, plus I went for higher riser height to further protect against water reversion, expecting to get longer than the 4 yrs with the cast iron. I have only had outboards before and had great trepidation about getting into the sterndrive, however I continue to be impressed by economy smoothness power and low noise plus I think inboard gives better feel to boat. Negatives are that you lose some deck space for motor cover, and maintenance costs will probably be higher than outboard, i believe reliability is determined by individual maintenance n regular flushing after use whether in board or outboard. My rig is quick out of the hole for crossing southport bar and plenty of power when coming back over bar against run out tide, hope this helps

[The-easyrider]

Bad luck with the risers Terry mine are at 6 years but I am expecting the job will need doing befor long and am planing to go the stainless road so I may be posting questions when the time comes. On the sea legend you dont lose any deck space with the inboard as the out board has a stowage area under the sink in the same spot as the inboard. Also I insulated the engine covers as the sea legend is not insulated like the cruisers, what a difrance that made. You can carry out a conversation at cruise speeds with out having to yell.

[kizza1]

hey megabite
what sort of money are you looking to spend on the sea legend?

[MEG-A-BITE]

Bad luck with the risers Terry mine are at 6 years but I am expecting the job will need doing befor long and am planing to go the stainless road so I may be posting questions when the time comes. On the sea legend you dont lose any deck space with the inboard as the out board has a stowage area under the sink in the same spot as the inboard. Also I insulated the engine covers as the sea legend is not insulated like the cruisers, what a difrance that made. You can carry out a conversation at cruise speeds with out having to yell.

Hi there what did you do to insulate the engine covers as the noise could be rather loud?
cheers

[PADDLES]

our risers are at the 7 year mark now, we inspected last year and figured we'd get another year so this year we'll chuck some new ones on. they're only corroded where the gasket turns up to catch the condensation and the manifolds are clean as and corrosion free. i'm going to stick with mercruiser genuine as i'm not yet convinced that the sheet stainless ones are the go. the cast iron dry joint type last up pretty good and will only come down in price in the future. our boat sits on a trailer too so at least it's not sitting in salt water.

[MEG-A-BITE]

Hi Paddles,

Can you tell me how dose one check this,to see if you need the risers and manifold parts replaced. Is is easy to check this.

I need to check this before I buy this boat.Dont want a 2k bill 3months down the line.:-?

thanks.

[PADDLES]

you'll have to unbolt them and lift them off and inspect. it'll cost you a couple of gaskets, theyr'e not cheap but it'll at least give you a good idea of what it's like in there. i reckon you should put this back on the owner, if he lifts the risers off and they're still good and you then buy the boat then the cost should come off the price of the boat, if you choose to walk away then you should at least pay for the new gaskets for him to put it all back together or alternatively negotiate a price to get the work done. new dry joint risers for this motor are about $450 each and the gaskets will be about $100 or so for 2. i just got northside marine to inspect ours when i last got it serviced but it's a relatively straightforward job if you've got the time and some sockets.

[The-easyrider]

Hi there what did you do to insulate the engine covers as the noise could be rather loud?
cheers
I used a self adhesive foam that is like able flex but about 25mm thick an comes in sheets from whitworths or bias boating. I think it was about 72 bucks a sheet at 1400mm x 1000mm. Then it was just a matter of scribing and cutting fitting and tapeing the edges and joins will post some pics if you want.
http://www.biasboating.com.au/p-1178-engline-insulation-141m-x-1m-x-25mm.aspx
I also just pulled the kill tank out on the weekend and insulated the tub so that it keeps the ice slurry a bit longer as I figure the heat from the motor was transfering to the kill tank

[PADDLES]

the cruisers have that foam the easyrider has used and then cover it all in an adhesive foil that is very similar to sarking for buildings. obviously things do get pretty warm in the engine box.

[The-easyrider]

That insulation comes with one side self adhesive and one side foil faced so all you need is to seal the joins and edges with a reflective foil tape it is the same stuff they use on the cruisers. I checked out the cruisers befor I bought the gear to do the job and was also mindfull of causing overheating problems by insulating the covers, but after checking the cruisers and drawing on experience from my own ski boat days went ahead and after keeping a close eye on engine temps for a while have found no adverce efects over a few years.

[testlab]

Hi Paddles,

Can you tell me how dose one check this,to see if you need the risers and manifold parts replaced. Is is easy to check this.

I need to check this before I buy this boat.Dont want a 2k bill 3months down the line.:-?

thanks.

How to put this politely.... no offence, but do you know what you are looking for if you took them off?

I am not familiar with the 6 cylinder Mercruisers but I know my way around the V8 (350/5.7 and 454/7.4) and I assume (at the risk of living out my signature slogan) they are similar.

There are different types of risers, manifolds and riser extensions, some are wet joint, some are dry joint and different gaskets are used for FWC and RWC. The manifolds are different for RWC, full system FWC and half system FWC.

The seawater that is used to cool the engine (after the heat exchanger in a FWC system) is injected into the exhaust riser after the elbow to keep the exhaust system cool and is then expelled with the exhaust gasses.

Prior to this the water has travelled up galleries between the outside surface of the riser and the internal exhaust cavity. This water is then mixed with the exhaust gasses after the elbow for expulsion.

The gaskets at the manifold riser joints can perform different functions depending on the system.

Risers need to be replaced because they carry salt water and they rust out between the sea water galleries and the exhaust cavity. When this happens sea water leaks into the exhaust cavity (with the engine off) and into the cylinder heads and cylinders. Likewise the gaskets leak due to corrosion of the mating faces. You can't tell if a riser is crook from outside inspection or in place testing.

Proper testing of the riser requires removal and pressure testing between the galleries and the exhaust cavity to eliminate pinholes and then visual inspection. If they are OK then the correct gasket is critical for reassembly.

Hope this helps. Sorry if it doesn't apply the V6's but I am sure it will be a similar system.

[PADDLES]

g'day testlab, i've got dry joint ones and they're pretty much identical to the v8 ones, i've not personally done mine, (because i just got mine inspected when it was serviced) but the guys at northside marine told me you can generally see excessive corrosion if it's present and with the dry joint ones you'll hopefully see leaks to the outside of the riser/manifold before they go into the exhaust ports, ie. they can't hide. like you say though, pinholes to the inside will be very hard to spot, but also very hard to actually create in a dry joint type, but pinholes to the outside will show themselves quite easily i would have thought, still, pressure testing is a good idea if you're suss.

my riseres are actually corroding from the exhaust side of the riser, into the gap between the cooling water passage and the exhaust pipe, it's apparently from condensation dribbling down the inside of the exhaust pipe from the riser and catching in the little upturned bit of the gasket and just sitting there and causing corrosion.

with the dry joint ones i thought the only difference between closed water cooled and raw water cooled was a different gasket that blocks off the cooling water passage, and a different hose arrangement to seperate the coolant from the raw water at the joint between the riser and the manifold.

[Suiblonde]

hi there i agree with snatchy 100% i just fitted the mercruiser v6 220hp 4.3lt alpha leg in a 24ft bertram, i have only done 45 hours. fuel consumption is spot on

[testlab]

with the dry joint ones i thought the only difference between closed water cooled and raw water cooled was a different gasket that blocks off the cooling water passage, and a different hose arrangement to seperate the coolant from the raw water at the joint between the riser and the manifold.

Thanks for the useful info on the dry joint ones. The manifold/riser gasket has two holes blanked off in the fully FWC ones and the different hose arrangement. The half FWC systems (manifolds are on seawater) are different again (but I haven't seen one) - there are occasional variations in manifold/gasket/riser between engine models. I don't know enough to say which goes with which but there are few variations but I don't know how significant/important they are.

Cheers
Dave.

[PADDLES]

hi testlab, i reckon it's a very clever/simple setup and the dry joint risers/manifolds are a huge step ahead of the old style. i've got mates with the older style and the only good thing about them is they're heaps cheaper to buy and replace. like you say, with the old style it'd be extremely hard to find leaks because the water galleries wrap around the exhaust pipe and everything's hidden away and you have no idea looking from the outside whether you have a leak into the engine. but these newer dry joint ones are a very clever design where they've stepped away from what you'd best describe as an automotive style of manifold cooling to what is essentially a seperate cooling water passage cast into the side of the manifold/riser.

like has been mentioned in an earlier post, mercruiser engines still do have that stigma attached to them, and it's come from those people who have experienced the heartache of the older design failing and then had an engine self destruct from water ingress, even though the newer designs have somewhat eliminated the corrosion issues of the past. that being said though, i'd never like to leave one in the water, but i wouldn't like to leave an outboard in the water either.

[testlab]

like has been mentioned in an earlier post, mercruiser engines still do have that stigma attached to them, and it's come from those people who have experienced the heartache of the older design failing and then had an engine self destruct from water ingress, even though the newer designs have somewhat eliminated the corrosion issues of the past. that being said though, i'd never like to leave one in the water, but i wouldn't like to leave an outboard in the water either.

I've had a few over the years and left them on a mooring - I will be doing so again (soon I hope). It helps when you can do some of your own maintenance, at the least checking things to make sure they won't fail unexpectedly. I think they are as reliable as any powerplant stuck in a hostile environment. Even diesels need the risers changed every once in a while.

[MarkIC]

Hi guys
I have a couple of questions regarding the whittley 660 cruiser with a 220 v6 mpi mercruiser too.
I've only just purchased this boat and so far it seems in immaculate condition for a 2005 model with 380 hrs. It is raw water cooled and has not been stored in the water. The owner was religious in using Macs salt remover to flush when returning from each trip. The boat has full receipts and was serviced each year.
The risers have never been off and and although there are no signs of rust or leaks it will be interesting to see what I find when I pull them off in a few weeks to inspect. I will keep you posted

Q1, should I also remove the manifolds for inspection as well if the risers are not in bad shape, they are the new dry joint type

Q2, the boat is running a merc High Five SS 17" prop and performs well with 4750 wot and a nice sweetspot cruise of 3370rpm for 42kph with a alpha II leg. Seems funny to run a 5 blade on a cruising boat like this even though this was Whittleys std ss prop option. Would a merc revolution 4 blade prop be a better cruising prop for these boats? I've only ever really seen 5 blade props on high hp ski and performance boats boats before. I'm looking for a good all round prop with best economy. The boat has smartcraft hooked up to a navman so fuel use at cruise is 1.35klm/lt with the high five, nice and smooth with good hole shot and no signs of cavitation at all.
Cheers Mark

[terryc]

It is not that hard to pull off the risers to inspect, though you will need a couple of riser gaskets to reinstall. My thoughts would be that if the risers are good then the manifolds should be good. It seems that the risers deteriorate quicker than the manifolds.
I have the same rig as you and find the standard 5 blade prop more than adequate, i doubt whether it could be much improved upon.
I reckon they are a great boat and hull design i take mine outside fishing off the Gold Coast and find it handles the sea excellent.
regards, terry

[PADDLES]

we've just replaced our risers and manifolds on our 2004 cruiser 660. they lasted 8 years and it's raw water cooled like yours and terry's. the 5 blade prop works fine. the big thing i've found with ours is that it responds really easily to weight distribution when you want to get it up on the plane. if i've got more than just us (1 wife + 1 kid) on board, i generally ask anyone on the back seats to jump forward a bit to let us get on the plane quickly and then they can sit back down and enjoy the ride. the 660 has a superb hull in rough conditions.

[The-easyrider]

I did my rmanifolds last year on a 2004 v6 mercruiser that had been well looked after. The out let for the exhaust was well restricted and this is in an area where salt water never goes so the first thing would is pull an elbow of and have a look up the riser.
85036

[MarkIC]

hi guys, thanks for the replies so far. The -easyrider I don't seem to be able to open the attachment, can you pm me an email or link to see it please
I agree with the handling comments, so far I'm very impressed with the ride and cant wait to add more hours.
Cheers Mark

[The-easyrider]

There you go fixed, I went for stainless was only 150 bucks dearer than cast so far so good but only time will tell they should outlast the mercruiser ones. There is a noticable improvment in power and economny but the way the old ones were restricted there was bound to be. I run a 3 blade ss prop on mine after canging the manifolds i did some prop testing and the 3 blade ss gave better results than the 4 blade ss and the 3 blade alli. I cruise at 44kph for 29l/h at 3250 rpm on good water with 4 POB