Ihave a 2001 MER XR6 150HP I pump it up and it runs good stop to fish and have to pump it up again and runs fine pain in the but going on 3 months now this is what i have cheaked and is good pickup tube and screen main fuel line to buble 5 new bubles from 5 dollors to 30,new hose from buble to motor ,ne fuel pump diephrame one , vent on gas tank and hose clamps , cheak valve that comes from oil into fuel line, floats in carbs are good 2 weeks for shop to look at it i need BOAT dont know anything else to try Thanks Mark Any help would be very greatfull

Viagra!! just kidding

You have a leak. Air some where from tank fittings to bulb or a fuel leak from bulb to carbs. Does bulb pump up firm. Pump bulb up and hold it and if you fill the bulb going down you have a fuel leak from bulb to carbs. The manual fuel pump can be difficult to get the gaskets and diaphram to seal up correctly.

Have you replaced you fuel lines in your motor recently. I had a similar problem and had a crack in a fuel line. The crack was not visible until I had taken it all apart. New fuel lines are a couple of dollars a foot at the auto part store.

Crappie Buster and Gary Purdy....I have a 2000 200HP Merc Opti Max and running on my R91 Ranger and have been having the same problem. The dealer wants me to run it in to put on scope to determine problems. If it is a gas line or bulb problem would the computerized equip show that? Seems like that would be a visual or common sense approach and solved through elimination? I can be idling through a no wake zone and she coughs once and dies. The bulb has completely lost pressure. Pump it up and off she goes. At first, it only happened once per trip, no problem. Recently, two or three times. I have checked the ball and connections and cannot see any leakage but realize it could be anywhere and small. Crappie Buster...good luck on the resolution of your problem and if you solve it appreciate on any suggestion. I will pass along the same....../Mike)

That Optimax is a different animal with electric pumps. Only other thing I have come across is the anti-siphon valve sticking. If the fuel bulb looks like it is mashed flat, check for resriction to the tank and if it is just soft, look for leak toward the motor. Yes BassnRoun the diagnostics can show a fuel problem if it is electrical but not a gas line or bulb problem.