stumped

[nwilliamsxo]

I have a 19' bayliner bowrider with a mercruiser 135 3.0. When it's parked in the driveway I can start it cold in neutral the first time. When I put it in the water, it's difficult to start - frequently requiring me to pump the throttle 2or3 times. The starting problems continue throughout the day while on the water. When I get it home, it starts right up in neutral the first time. Is there any correlation? Help!

 

[Fun Times]

I have a 19' bayliner bowrider with a mercruiser 135 3.0. When it's parked in the driveway I can start it cold in neutral the first time. When I put it in the water, it's difficult to start - frequently requiring me to pump the throttle 2or3 times. The starting problems continue throughout the day while on the water. When I get it home, it starts right up in neutral the first time. Is there any correlation? Help!

When at home do you have the bow of the boat all the way down or close to it using the trailer jack so that you can lower the drive all the way down?

If so then your float bowl adjustment may be off a little bit while the bow is up on an angle at the launch ramp and there may not be enough fuel in the bowl to start it up or maybe even to much fuel and you could be flooding the engine.

You could pull you spark plugs and see what they look like.

Your choke may not be working right.

You may want to pull off your flame arrestor and look to see if you have any fuel or not inside the carburetor. Do not try to start the engine with you face over the carburetor though.

When was the last full tune up?

Has this always done this or just all of a sudden?

What have you tried so far to check this out?

How long does the boat sit before you try to start it up at home?

 

[nwilliamsxo]

I forgot to mention that the boat diesels intermittently, sometimes pretty bad, but only in the water. We bought the boat last summer and the symptoms have been the same from day one. Up until late April/early May this year, the boat has ran great when it starts. Then, I couldn't get it started at home. We took it to the shop, had the carb rebuilt and a fuel/water seperator installed-water in the carb. Took it home-same thing, fired up nice in the driveway, difficult on the water. Haven't checked the plugs. Plug wires look good. Dist cap points look a little rough. Oh..and the bow is down just a little. With the trim all the way down, couple inches from ground. The boat sits up to a week or so and usually fires right up.

 

[Chris E]

2 to 3 pumps on a carb motor is completely normal. i have a 3.0l and it fires on the second pump, but will not start ever without a shot of throttle. every engine behaves differantly. i can't explain why it behaves the way it does on land, the only logical explanation i can offer is that you have a lack of back pressure on shore that you don't have in the water.

3.0l's are cranky at the best of time. these are industrial engines, never designed for marine use (although they do work fairly well). but because of their displacement, they tend to shake and shudder and they are fairly loud.