[dansndais]

Hello, I purchased a 115 ELPTO Mariner out board new in 1995, serial #0G213948, it powers my 18 foot Smokercraft. I purchased this motor because I do a lot of trolling, about 12 times a season, 6 – 8 hours each time and I was told this four cylinder four carburetor motor drops to two firing cylinders under 1000 rpm. That’s great I can troll as low as 1.5 mph. I get out on the big lake and advance slowly to full throttle because shifting quickly to full throttle the motor will bog down and want to shut off. After an hour or so of high speed running, I will throttle down to a stop and the motor will invariably shut off on its own. I will ready my fishing lines and restart the motor, rev it in neutral and slam it into gear. This gets me trolling. When trolling for a couple hours I find that the engine starves for fuel so I have to pump the primer bulb on the fuel line every 20 minutes or so. I will stop trolling and run the boat for 10 minutes or more at high speeds to clean the motor of any build up. Then coming to a stop, the motor will shut off on its own and I have to restart it, rev it in neutral and slam it into gear to get trolling again. Then invariably it will starve for fuel again. There is occasionally an episode when shifting body weights to tilt the boat to starboard or port will affect the running of the motor. That is when shifting body weights, the motor will want to quit or will run rougher. The motor will also run rough if it is not trimmed just right.This has been a problem over the years. Two different dealers have rebuilt my fuel pump three times over the years. They claim the alcohol in the gas now a day eats up the diaphragms in the fuel pump. OK, so the pump was last rebuilt in 2001 with a new kit Mercury came out with. I guess I must be due for a new fuel pump!I’ve never been real happy with the performance of this motor after the dealer visits. Although it seems to troll better after the pump is rebuilt, it seems to me that I should be able to push that throttle forward quickly and be able to accelerate quickly. It never really has done this. And why does it quit after running at high speeds and coming to a stop?I am not a motor mechanic but I am mechanically inclined and have tools. My intentions are to rebuild the fuel pump myself this time. Is there something else I should be looking at? Is it something I can do myself?I picked up a Clymer manual for help.Thanks for what help or advise you might give,Dan

[Clams Canino]

The most important thing to remmeber is that the pump SUCKS gas up. So vatch for any vacuum leaks in the ENTIRE fuel system before the pump.-W

[dansndais]

Yes, great approach. I had the manufacturer check the gas tank for leaks beacause I have smelled gas in the bilge. It checked out OK. I have still smelled gas there. I have now pulled the three hoses out for replacement. (gas supply, vent, and gas fill hoses) Now I've got to locate replacements.Do you think that a possible vacuum leak caused by one of the hoses would cause the acceleration problem?