Boat's Going Slow

[silver_boy]

Boat\'s Going Slow

Ok, the boat's an '82 Fairline 32 sedan with twin volvo aq175 petrols (v6, 170hp)

Problem is they are both only doing 3000rpm flat out instead of the 4800 they are meant to do. It's just getting on the plane and no more, doing about 17mph, should be closer to 30.

Replaced the fuel filters last week, the spark plugs a couple of months earlier. Hasn’t been lifted out and scrubbed for a while but it’s in fresh water so I don’t think it should be too bad. Would rubbish on the bottom cause it to lose that many rpm? Another possibility is it might be running too rich. Is there an easy way to check this without paying a nice Volvo man lots of money? When we took the old plugs out they didn’t look too black.

Anyone got any other suggestions about what could be wrong or if it’s likely to be the above things? And how to fix them?

Cheers

 

[volvopaul]

Re: Boat\'s Going Slow

get the bottom cleaned especially the props it will make a big difference

 

[hlb]

Re: Boat\'s Going Slow

Probabley the bottom. Check the revs and speed with only one engine going. Then see what the other does.

 

[Frontier]

Re: Boat\'s Going Slow

Have a look at the air filters, I had this and mine were really black.


It may not be them but worth eliminating.

 

[volvopaul]

Re: Boat\'s Going Slow

hlb hows the p35 going is it still floating in salcome are you back on the water yet, you didnt give us an update as to what went wrong.

 

[silver_boy]

Re: Boat\'s Going Slow

Hlb - I am right to assume that with just the one engine running it should do more than 3000rpm if it is the bottom?

Frontier - Forgot to mention them - cleaned them out a few weeks ago so they're good and clean - thanks anyway.

 

[overdrawn]

Re: Boat\'s Going Slow

you will get even less rpm from one motor only,but if one gives less than the other it is appreciably down on power /forums/images/graemlins/smirk.gif

 

[aquaholic]

Re: Boat\'s Going Slow

if both engines are down to 3000 I would think it would have to be growth, what are the chances of both engines developing the same fault at exactley the same time ??
unless of course its a fuel delivery problem. Fresh water or salt water both will allow speed eating stuff to growjust different types.

 

[silver_boy]

Re: Boat\'s Going Slow

Thanks for the suggestions guys. I'll try to get the bottom scrubbed soon and see if that fixes things.

Cheers

 

[hlb]

Re: Boat\'s Going Slow

No, it would not float anymore!!

It's awaiting quotes and insurance claim. I'll let you all know, once sorted out.