Humbly I will admit I'm no grease monkey and don't have the pedigree to troubleshoot most issues with my boat (or any other vehicle for that matter). Have a 2009 GTR35 (briggs) with <200 hours on it. Runs great in cool/cold duck huntin weather. Runs great on any day trips any other time of year out of the garage. Runs great when we bring it down the shore for summer vacation (running in back bays of South Jersey fishin and crabbin) for the first day or two of the week. Now, for past two summers, we have had the same thing happen: later in week the motor will not run smoothly, no propulsion, and spits/sputters like its got bad gas. If you've ever waken up at the Jersey shore, the humidity over night is about 110% and everything is soaked like it rained even when it didn't. I keep the fuel tank tucked up under the front deck of the boat, but I assume that moisture is getting into the fuel, carb or both. I run sea foam in my fuel normally and NEVER let the gas sit more than a couple days, let alone weeks. This week, while down the shore and after the motor took a crap on day 4 of our trip, I bought a new gas can and connectors to rule that out ($100 experiment that didn't solve anything). When I get home, store it in the garage for a week drying it out, and swap out the gas, I'm fairly confident it will run like a top again. Anybody have this happen to them? Any solution to prevent this in the future?

Could you post this thread one mo gin plz?


Sent from my iPhone using Tapatalk

Don't go to the jersey shore.

Does your gtr have a spray tan?


Sent from my iPhone using Tapatalk

Its not GTR, its GTL................

There is a wealth of information here on fuel system problems and most of them are corrected by fixing a very small air leak. Do some research here with the seach function. It's cheap, easy and you probably will learn something.
There is a possibility it is not fuel. It may be ignition caused by moisture buildup in wires or coil. When it starts to act up try to start it with one plug wire removed. If it starts and runs on that cylinder see if it will start and run on the other cylinder alone. If one cylinder exhibits problems I would suspect a bad coil or wiring to that coil. The combination of salt water corrosion and moisture can introduce all sorts of gremlins so cleaning up your electrical connections may improve things. let us know if you find anything.

^ this I've had problems on very muggy humid days. Occasionally motor would drop a cylinder and run rough. I finally found the issue early one morning in the dark I saw the plug wire arcing to the motor. May wanna check your plug wires and boots.

Best way to tell if it's arcing is make sure you're barefoot and grab the wires lmao! Let's ya know real quick

Sent from my SAMSUNG-SM-G890A using Tapatalk

First and foremost... appreciate the Jersey shore humor Walked right into that one.

I did try a search on some of the possible causes and got caught up in the debate of ethanol and fuel additives, which is why I posted my own thread. Very helpful tips on the coil/plug wire route, like I said, motors aint my thing but should be able to run down some of those paths to see if they bear fruit. I'll report back after I'm done electrocuting myself (or maybe I'll keep my shoes on!).

I had the same type of problem. It was solved by placing a small amount of dielectric grease around the porcelain section of each plug. This prevented the spark from going to ground instead of thru the plug. Worked like a champ, good luck.

I had the same type of problem. It was solved by placing a small amount of dielectric grease around the porcelain section of each plug. This prevented the spark from going to ground instead of thru the plug. Worked like a champ, good luck.