Volvo Penta aq125a No power, Help.

[skeeterjo]

First of all the boat ran fine when put away for the winter. During the process of starting the boat for the first time this season, the it cranked well but would not start, eventually found that the fuel pump was bad. After replacing the fuel pump, the timing belt broke while cranking the engine. I followed the proceedures for replacing the timing belt (values on #1 cylinder closed, #1 piston at TDC, accessory pulley, Distributor rotor all lined up with markings.) When replacement was done the boat started and I was able to fine tune ignition timing, and points gap. Engine ran well but would flood out after about 5 minutes. Then rebuild the carburetor (solex down-draft) and boat started right up and runs great. Actually, runs smoother than it has in the past. After clearing the no wake zone on the first trip out, and pushing down the trottle I found that the boat had no power, not even enough to plane-out. It will only push about 1800 RPM's at full trottle even though the engine sounds and feels great. I did check the trottle cable, and it seems to being operating the carburetor correctly. However, I noticed raw water leaking from one of the freeze-out plugs on the exhaust manifold, which caused the engine to run a little warmer than usual (180-200 degrees). Any ideas on where to start touble shooting the lack of power, I am confused about where to start because the engine is running so smoothly.
Help please.

 

[Mark2009]

Re: Volvo Penta aq125a No power, Help.

Sounds to me like a lack of fuel. check for bent fuel line or maybe water in fuel filter or carbs.

Hope this helps.

 

[skeeterjo]

Re: Volvo Penta aq125a No power, Help.

That's what I am thinking. It starts to accelerate for the first quarter of trottle but no difference for the last 3/4. How do I check the volume of fuel going into the carb. and how does it increase as the trottle is pushed down? Is it possible the timing has jumped and the engine still runs smooth?

 

[P 0 P E Y E]

Re: Volvo Penta aq125a No power, Help.

I would look at your dip stick to see if you a making a milk shake (water in oil)

Was the engine winterized properly? The fact that you had to change engine parts while trying to start the engine for the first time of the season, combined with a leaking freeze plug sounds scary.

Check your combustion chambers for water.

Double check all your work.

To answer your carb question: the carb has a float bowl that holds a small quantity of fuel. As the fuel is used by your engine (drawn thru the main discharge nozzle by Bernoulli's principle of the inverse relationship between pressure and velocity) Fuel is supplied to the float bowl by the fuel pump,the fuel enters the float bowl when the float sinks to a height that unseats the float needle, fuel stops entering the float bowl when the fuel in the bowl causes the the float to rise to a level that closes the needle on it's seat.

The Carb also has an accelerator pump, like a mini squirt gun this pump squirts fuel as the throttle is suddenly opened.

There is a filter at the inlet of the flat bowl that may need to be replaced, saw this on my boat. My boat was running out of gas at high demand, proved this hypothesis by squeezing fuel into the vent hole with a squeeze bottle.

Hope this hepls......