Please help, poor performance

D

daddycool

New Member
Joined
5 Jul 2010
Messages
15
Visit site
Hi all

Just has a lovely weekend albeit a very slow one, my AQ211a revs when idle easily over 4000rmp, however when under load out at sea and in the harbour it will not power any more than 7 knots, 2000 rpm, there is nothing there, it is completely gutless. For a boat that is supposed to power in excess of 35knots I am at a loss as to what the problem could be!!!!!!

I have had all of the engine electrics replaced and the carb has been overhauled.

I have only just bought the boat so have never experienced any more than 8 knots from it.

Does anybody know what the matter could be, your thoughts and ideas will be most welcomed:(
 
daddycool said:
Hi all

Just has a lovely weekend albeit a very slow one, my AQ211a revs when idle easily over 4000rmp, however when under load out at sea and in the harbour it will not power any more than 7 knots, 2000 rpm, there is nothing there, it is completely gutless. For a boat that is supposed to power in excess of 35knots I am at a loss as to what the problem could be!!!!!!

I have had all of the engine electrics replaced and the carb has been overhauled.

I have only just bought the boat so have never experienced any more than 8 knots from it.

Does anybody know what the matter could be, your thoughts and ideas will be most welcomed:(
Click to expand...

Dirty bottom ??????
 
The boat is a Fairline sprint 21, it only went in the water 2 weeks ago after just being antifouled. the Engine is a Volvo Penta AQ211A with a 290 stern drive. I am new to this so that is all I know, the only thing I know about the Prop is that it is a duo prop.
 
Well good news is that the Fairline Sprint is a very capable boat, and we have an expert forumite on the boat named Solitaire, who used to own one.
If the duo props are OK and correctly pitched and sized for the boat (hopefully someone here can advise on that) and the hull is clean, then it sounds most likely an engine problem.
 
Ok, thanks, I hope the engine is ok, otherwise I've bought a duffer!!!!
I dont know about the prop, would have to be advised, I hope somebody can help me get to the bottom of this, I am paying for a pricey berth at Cobbs quay and have a boat that will not perform, its like owning a Jag that can't get above 30 mph!!! LOL
 
no sea trial was carried out, kind of inherited boat at bargain price!!! Never had a boat before, so not bad to learn in at only 7 knots, we are learning fast though!!!
 
Hi, and welcome to the forum!

First of all, don't panic too much. A boat engine needs to be working really well for the hull to get over the "hump" and onto the plane to higher speeds. Even quite a minor problem can prevent this happening and keep you at 8knots. It's deeply different from the situation with a car, where you probably wouldn't even notice a small loss in performance.

For starters, what about the mechanics that "replaced the electrics" and did the other work on the engine. Was the boat sea trialled after they finished? Might be worth getting them back, depending on what the arrangement with them was.

If it were me, I would be thinking about getting a good mechanic to take responsibility for doing the initial fault finding. Take them out with you if necessary. Easy things to check should include testing spark, advance, compression, fuel (lift pump?) etc. etc.

You could pm "VolvoPaul" or "Col" of this forum.

dv.
 
Last edited:
Thanks, no the boat wasn't sea trialled, the work was done as on dry land it would not start, after elec work was carried out it was then put in water to run engine fully, it sound purfect when idling and revs up perfect, a compression test showed 170psi from each cylinder and this is all I know, somebody else said to me about the prop as the boat does tend to drift when on the sea but i just thought this was the natural current of the water, I really just dont know, but also don't want to pay out for a mech who will just say it maybe this or that or that etc like I have an endless bank account!!!
 
one thing I will add is that an awful lot of fuel seems to be used when out on the water, also you can smell it when travelling, there is no leak anywhere before you ask.
 
I suspect you really do need to get a decent mechanic to come have a look and take it out for a run with out, or at least a mechanically minded forumite local to the boat, who can dismiss some of the obvious possible problems.

Another thought, though I wouldn't place as much emphasis on it at this stage. How many people, and how much gear did you have on board with you?
I know Solitaire occasionally, when he had the family and a weekend aways gear and full tanks, had to send crew forward to get on the plane in the rough. Might be another factor worth considering.
 
BrendanS said:
I know Solitaire occasionally, when he had the family and a weekend aways gear and full tanks, had to send crew forward to get on the plane in the rough. Might be another factor worth considering.
Click to expand...

That was when I was running the AQ205 with 5 up when we went down to Weymouth. As you know, I had my Sprint for a long time and in fact would have another one. Great boat, great hull and i am looking for another one - don't care about engine as I will dump it and put a Yamaha diesel in it.

The OP's problem is with the engine - or the hull is dirty. Could also be that the engine is just old and while it will rev in while out of gear, if it will not pull under load. can't really make a comment unless I was to sea trial it.
 
only wife and 3 small kiddies, not alot of weight at all.
Someone has mentioned a perforated fuel pump diaphram maybe the cause, as this would cause fuel starvation to the carb as the fuel would be diverted to the carb screen hence the reason why I am only reaching 8 knots, usiong a heck of a lot of fuel and can smell it when travelling and when idling on the pontoon.
Is this true? worth a look and spending money on?!!!!:confused:
 
daddycool said:
only wife and 3 small kiddies, not alot of weight at all.
Someone has mentioned a perforated fuel pump diaphram maybe the cause, as this would cause fuel starvation to the carb as the fuel would be diverted to the carb screen hence the reason why I am only reaching 8 knots, usiong a heck of a lot of fuel and can smell it when travelling and when idling on the pontoon.
Is this true? worth a look and spending money on?!!!!:confused:
Click to expand...

What engine/ AQ205 or the 211?
 
As already said, get a good engineer to take it out for a spin with you, or find a friendly forumite that knows engines to come for a trip. They'll be more able to diagnose. Forums can help with detailed knowledge if they know roughly what the problem is from forumites that can provide detailed diagnostics. At the moment, you seem to need some diagnostic help
 
You must log in or register to reply here.

Share this page

Top