my boat wont go fast

[allcav]

I have a 1971 sierra with a aq130c volvo-penta 4cylinder with a 270 out board. My prop is 14 3/8 d 17 p. I first bought the boat and took it out it only went 10 mph and 2800 rpm. I took it back and he had a mechanic look it over and he said it was to spec in all areas. I took it back out and it did the same. I forgot to mention it was back firing out the carbs. My brother looked at it while we were out and notice the fuel filter was striving for fuel. I went out and bypassed the original mechanical fuel pump and put a electric one in.
I took it out and it got up to 14.5 mph and 3200 rpms but very bad weather. 2 foot swells with lots of wind.
is this normal for this boat. is the prop right?

 

[NSBCraig]

Re: my boat wont go fast

Sound horrible to me.

If you don't get a answer try the prop section, cause your probably on the right track if you sorted out the motor problems.

 

[Bondo]

Re: my boat wont go fast

Ayuh,... Welcome Aboard,... You're in the wrong forum,..

We'll see if a moderator will move this to the I/O forum...

 

[allcav]

Re: my boat wont go fast

sorry. I was told to start new thread.

 

[JimMH]

Re: my boat wont go fast

If it is backfiring then it is not to spec. You should take it to a Volvo dealer and let them look at it. I would think that you would get at least 30-35 MPH out of that set up when it is working right.

 

[Bondo]

Re: my boat wont go fast

sorry. I was told to start new thread.

Ayuh,... I editted,... A Mod. will move this 1 for you...

I took it back out and it did the same. I forgot to mention it was back firing out the carbs. My brother looked at it while we were out and notice the fuel filter was striving for fuel. I went out and bypassed the original mechanical fuel pump and put a electric one in.

You're fighting Atleast a fuel delivery Issue,+ the fuelpump you put on it probably isn't wired correctly, with a Fail-safe circuit...

 

[allcav]

Re: my boat wont go fast

getting forgetfull. after the new pump, the backfire stopped after all the air was out of the lines.

 

[allcav]

Re: my boat wont go fast

if wet foam (massive weight) was the issue, how do you fix this?

 

[BRG25]

Re: my boat wont go fast

You need to get the motor running correctly before you get too far. It sounds like you are not even close to hitting WOT (Wide Open Throttle). You should check this on a relatively calm day with the motor trimmed out. Sounds like at a minimum you need a full tune up and also check your timing. What is the compression on the motor? Like others have mentioned how did you wire the fuel pump? That's a good way to blow up if wired incorrectly...

 

[HVAC Cruiser]

Re: my boat wont go fast

if wet foam (massive weight) was the issue, how do you fix this?

Are you asking because you found the wet foam? If so, not to sound funny but thats a different section too. Over in the Restoration section you will find tons of reading on waterlogged foam replacement, deck replacement etc. If your foam is soaked chances are good that you have rotted stringers,deck etc .

 

[allcav]

Re: my boat wont go fast

the pump is connected to the switch to turn the boat on to the battery. I was just asking about the wet foam (massive weight).
now my brother was talking to me about the trim and I didnt know about it.
he told me while i was driving i should bring the motor up a little. I didnt know this.
right now the winds are bad in northern nevada so i wont be able to try it for about a week.
Could 2 foot swells drop speed by 10 mph and rpms?

 

[Bondo]

Re: my boat wont go fast

the pump is connected to the switch to turn the boat on to the battery.

Ayuh,... That's a Bomb, lookin' for reason to Explode....

It's gotta be wired, from the igntion circuit, through an oil pressure switch, to the fuelpump...
That way, if the motor ain't runnin', there ain't no oil pressure, so the feulpump won't run...

Not trimming Up, is probably more the fault than the waves...

 

[Don S]

Re: my boat wont go fast

99% of the 270 drives do not have trim, only an electro mechanical lift. Can you post a picture of your drive and engine setup INSIDE the boat. They have a pin that limits the down travel of the drive
When you are going at top speed is the bow of your boat low in the water or does it come up about level, or maybe too high?
I would be worried about haveing an electric fuel pump on it. WHY???? did someone decide the fuel pump was the problem when it wasn't? Sounds to me more like a fuel problem getting to the pump.
Have a look at this thread, and do the tests.
http://forums.iboats.com/showthread.php?t=283269

 

[allcav]

Re: my boat wont go fast

I dont know how to post a picture but its an up down button I have to manually push.
whats your suggestion on the fuel pump. since I changed it, I dont run through 2 batteries to start and its more responsive.

 

[pcmpete]

Re: my boat wont go fast

I had the same problem when I got my AQ130c (same outdrive and prop). But after adjusting the valves, replacing plugs and points, checking the advance on the Dizzy and setting the timing my 16 footer now runs approx 40mph with 4 people on board.
Like everyone else said, get a manual. You won't be sorry.
Do you get fuel coming out of the J-tubes on the carbs with you pump the throttle?

 

[achris]

Re: my boat wont go fast

Sounds to me like there are a few issues here, and they need to be dealt with separately.

1. Old mechanical fuel pump.
2. New electric fuel pump .
3. Wiring of the electric fuel pump.
4. engine tune.
5. Possible wet foam.
6. Trim system (if it has one).

The biggest concern to me would be the wiring of the electric fuel pump. You need to get that right PRONTO!!, or you'll be speaking to us from the other side.

You need to do a full tune on the engine and make sure that's right. That includes compression test, changing spark plug, points, condenser, rotor, and the fuel filters, and setting the timing and idle speed and mixture(s).

Then, and only then, can you start to deal with prop and speed issues.

0.02

Chris........

 

[JaseBosto]

Re: my boat wont go fast

yea watch out for that wiring.....boom