Twin 200 Yamahas on a 25 FT Sailfish Stall Out

[simpsonhsny]

Recently purchased a 25ft Grady Sailfish with twin 200 Yamahas 2 stroke Saltwater Series, boat is a 1992, re-powered in 2000, motors have roughly 200 hours on them. We were out on the water today, balls pumped hard, ran for 20 minutes, stopped, fished for a few hours, motors started right up and on the way in after 15 minutes motors stalled, started again but quickly stalled. Pumped balls, no response, switched to aux, same respsonse, towed in to get gas, filled one tank with ten gallons, and other was filled after 3 gallons. Repeated pumping balls on both aux and main, motors start at best and stall. Balls never get hard! Any thoughts?

 

[seasick]

If the primer ball colapses, there is a fuel blockage. If when not running the motors, the primer bulb never seems to firm up and you confirm that gas is not being pumped into the motor's filter, then there is air getting sucked into the system. Also check the position of the main/aux tank selector.
It is unlikely that both bulbs went bad at the same time. It sounds like a plumbing issue to me. Did you try selecting different tanks? You might have a bad pickup in one of them.

 

[bayrat]

Sounds liked you may have lost prime (for any number of reasons). First, check to see if your tank vent is working and not obstructed. Could be why you couldn't get much gas into the tanks. As far as the balls getting hard ; point the end closest to your engine towards the sky(vertical) and try pumping it again. The check valve in the ball frequently doesn't work when the ball is horizontal but when you go vertical it may well go hard. Let us know how it works out.

 

[seasick]

Sounds liked you may have lost prime (for any number of reasons). First, check to see if your tank vent is working and not obstructed. Could be why you couldn't get much gas into the tanks. As far as the balls getting hard ; point the end closest to your engine towards the sky(vertical) and try pumping it again. The check valve in the ball frequently doesn't work when the ball is horizontal but when you go vertical it may well go hard. Let us know how it works out.

Assuming the low pressure pumps are working, a blocked vent will result in a collapsed primer bulb.

 

[bayrat]

Assuming the low pressure pumps are working, a blocked vent will result in a collapsed primer bulb.[/quote]

If the vent was totally blocked , I'm sure that it would. However I'm not sure that a partially restricted vent couldn't cause this problem especially with 2 engines pulling on the same tank. I just cant think of any other common denominator here, can you ? As you mentioned , the probability of 2 balls going bad at once is not likely . (ditto for 2 fuel pumps, 2 anti siphons, 2 pickups).