Under-performing Rinker Fiesta Vee 250

[rafiki_]

It appears that the engine is not producing sufficient power. Ask the seller to sort it out or walk away. There are plenty of others.

 

[ontheplane]

I had a Rinker 260V with a Mercruiser 5.7 V8 220HP Carb engine and bravo 2 leg.

When completely clean bottom, lightly loaded and all good she did 41mph (GPS logged) don't know what that is in knots...

17mph is totally wrong - and take it from a man who did it, don't buy a boat with an underperforming engine - I cost me £2000 to eventually sort out a really really simple problem because we didn't know where to start so had to start with the obvious and work all the way through.

My problem was that the cambelt had been put back on 3 teeth out - i was amazed it hadn't bent a valve, but that's by the by....

If you are going to buy the boat and then sort out the engine - budget for a whole new engine, and in my case I wish I'd done that! If you can get a new diesel for example for £10k, and you get the boat 5k cheaper because they can't fix the engine, well hello you've just re-powered with a new diesel for 5k - that's not a bad thing!

DOH! That's me being stupid.....

There are two things in my post - the Rinker with the v8 never had the under-power problem, that was me just posting an idea as to what the boat should do.

The engine problem with the cambelt fitted wrong was in my last boat - a Farline Weekend with a AQ145 volvo in it!!!

Sorry, having re-read I can see why the confusion.

The point I was trying to make is that if you suspect an engine problem then either reduce price by enough to buy a complete new engine or walk away. If it was a simple and cheap fix then the existing owner would fix it - I suspect they've spent a lot of money and can't fix it, so are trying to sell it on to someone else!!!

Yes it may be something simple and obvious, but I wouldn't want to rely on it!

 

[tinkicker0]

Hi all,

I've recently had a sea trial on this 1992 Rinker with a view to buying it if the pre-purchase survey goes OK.

I am concerned however that the boat is under-performing as it would only get up to 17knts on a very calm sea (it should cruise at 24 with a maximum speed of 30knts apparently). I am also concerned that the pre-purchase survey won't cover this problem.

The engine is a V8 petrol Mercruiser (260hp) that has recently been reconditioned and fitted. I noticed during the sea trial that the oil pressure was fine, the temperature was fine and it ran very smoothly. The hull has just been scrubbed so that shouldn't be a problem either.

Has anyone got any ideas why it might be under-performing like this?

Any suggestions gratefully received!

Just had an idea. Reconditioned you say, by who?

Mercruisers differ internally from stock GM engines in some areas:

Gaskets.
Pistons.
Camshaft profile

Gaskets are marine quality to stand up to salt water,not too much of a problem in certain areas if you have freshwater cooling.

Pistons are usually of the high quench area variety, not standard automotive.

Camshafts are reprofiled to give better low to midrange performance than stock automotive.

If you are lacking midrange power, the motor may be lagging way behind the on the power /drag curve and that may be why it cannot get on plane.

A smaller pitch prop may help, but you need to find out if the motor has been fitted with a new cam, it may well be an automotive one.

 

[MapisM]

Forget all the "doom and gloom walk away" brigade.

Fwiw, I'm joining that brigade.
I'd never purchase a boat from someone who's bringing me out for a sea trial on a boat in such conditions, period.

 

[PCUK]

You'll never find a bargain then Mapis!

 

[AndieMac]

There are a lot of automotive V8's and V6's going in to repower boats because they are so cheap. The mechanics (often not necessarily marine mechanics) fit them up in the shop, test them with flushing units and they run fine.

The problems start when the boat goes in the water..... won't idle properly (back pressure) and just won't pull like they should, or like the old engine did.

The camshaft must be changed, taken from the old motor (original Mercruiser) and put into automotive engine (if still serviceable), or a mercruiser replacement.

As Tinkicker said the pistons are of a high performance nature, so a standard 5.7 litre carb. automotive engine (if indeed this is the case) is not going to perform like an original mercruiser, possibly 30 h.p. less.

If raw/sea water cooled, the engine water circulating pump should be replaced with one with a brass impeller.

I,ve heard mentioned that the folks at Mercury (Mercruiser) know more about these engines than the original builders, due to the R & D done to perfect their performances in the different applications.

 

[Bilgediver]

Forget all the "doom and gloom walk away" brigade. Before you do anything else, make sure the prop' is matched to the engine. It may still have the old prop' from before the new engine was fitted. This is the most likely and most obvious cause of this type of problem. What ever it is it will be simple to rectify with a little thought.

My thoughts too....maybe different gearbox ratio so overpropped. Needs the correct pitch for the new engine/gearbox.

 

[AndieMac]

I have a similar sized boat in Italy, 24 ft with 2 cabins ,toilet and kitchenette and running a 1990 230hp Volvo V8.

With 100l of fuel and 3 people on board with all our stuff, I have to use the trim tabs and get people sitting as far forward as pos to get it to plane.

Once up on the plane ...it flies.

seems to me the problem is It wont plane.The trim tabs wernt doing their job ,everybody was aft and too much weight at the back perhaps.

1. move all weight forward into V berth area.
2. get everybody to sit as far forward as possible.
3. Put boat on a diet,ie less fuel, water,people and junk.
4. get trim tabs working properly.
5. put in less fuel.
6. hull may be a bit fouled.
7. Prop may????? be wrong.
8. may be 20 years of antifoul adding to the weight problem.
9. maybe the antifoul is very rough and creating resistance.
10. remove all the fresh water bar what is needed.

I recon that with a bit of tweaking it will plane.Time to reduce price further.

Andy..... can you pull full rpm's (4200). I had the same problem trying to pick up a couple of knots at cruise (3000), so I went to an 18" four blade (from a 17" 3 blade). Cruise did just fine, but holeshot was rubbish and could only pull 4000 up top.

You could feel the engine labouring right through the range though.

The 18" is now the spare!