fast....slooooow.....fast......sloooow.

[suzuki40]

I am having a problem with a 1979 johnson seahorse 4 hp. Model # 4w79d<br />The tank was run dry coming in from the lake. Had to paddle in. Next day I poured the last of the gas from the 3 gallon plastic gas can. Took the boat out to fish again. This time it started up just fine,idol was great. I went to WOT and everthing was great. Then all of a sudden all power just dropped to about an idol speed for about 2 seconds, then it would pickback up to full speed again for about 5 seconds then it would drop off again? fast, slow, fast slow, it bugged the heck out of me. When I am at idol speed to half throttle,it runs fine? Could I have water in the gas? junk in the carb? I have a very good inline filter. The gas can was left in the rain but I didnt think any water got in?<br /><br />Suzuki40

 

[rickdb1boat]

Re: fast....slooooow.....fast......sloooow.

Water in the fuel or junk in the carb is likely. Try fresh fuel and if that doesn't get it, rebuild the carb or at least take it apart and clean it. Do you have a Water/Seperator filter?

 

[DJ]

Re: fast....slooooow.....fast......sloooow.

suzuki,<br /><br />I think you answered your own question. Contaminated fuel, most likely.<br /><br />You may also be dropping a cylinder-electrically.

 

[suzuki40]

Re: fast....slooooow.....fast......sloooow.

I just needed some reassurance. The motor is a jem to run. starts first pull run like a champ. It just started this right after filling her up again. it doesnt die out just kind of boggs down. I dont have a water seperator filter?<br /><br />Suzuki40

 

[quinnf]

Re: fast....slooooow.....fast......sloooow.

I have one of those, too. Sounds like one cylinder is cutting out, just like what water would do. I doubt it's electrical since it happened immediately after you emptied the last gas out of a can, never a good thing to do. First thing to do is empty the gas out of tank, lines and carburetor and refill with some fresh pre-mixed gas. If no joy, you may have clogged the high-speed jet with crud from the bottom of the can. In that case you'll probably have to remove and clean the carburetor and blow out the fuel lines.