3000 RPM and higher "slogging"

[KRS]

Hello Everyone. Some of you may remember my blown coupler that required several posts here. It ended up that the engine mount was rotten and needed replacment.<br /><br />Finally picked it up from the mechanic and took it to the lake. It was slogging at 3000 + RPM. I thought about a dirty fuel/water separator. I haven't seen a fuel filter on the boat, I am guessing this separator is a dual purpose unit.<br /><br />Any thoughts about this problem. It was dropping rpms and noticeably slogging. Rpms would drop 100-250, then work back up, and then slog again.

 

[Don S]

Re: 3000 RPM and higher "slogging"

I very well may need a complete tuneup. Plugs, points, condenser, cap, rotor set the dwell and timing and check the advance timing.<br />The 140 didn't have a water seperating fuel filter in the system, so hopefully you have one added on somewhere. There is a fuel filter for particulates (not water) in the fuel pump. If you did get water it's in the carb.<br />I would strongly suggest you get a water seperating fuel filter and install it between the tank and the fuel filter, and check it regularly for water contamination.

 

[KRS]

Re: 3000 RPM and higher "slogging"

The fuel water separator canister is called a "Sierra" with the following number: 187844. Where would the fuel filter be? Is it inside the tank?<br /><br />I will pull the distributor and see what it looks like. Also the spark plugs.<br /><br />FYI, I have the 120 ( I believe ).

 

[Don S]

Re: 3000 RPM and higher "slogging"

Sierra is an after market parts manufacturer. The filter could be anyplace on the boat except in the tank. Just follow the fuel line from the tank to the engine, if it's there you will find it.<br />Yep, the catalog is for both the 120 2.5L and the 140 3.0L I just read their heading wrong.

 

[Hog Wild]

Re: 3000 RPM and higher "slogging"

It's either a fuel filter or ignition (timing, distributor, plugs). I'd more guess this is still fuel related. It runs fine at idle though? Bad fuel should give a horrible idle? Only a plugged filter should act like your mentioning. Ignition can always be a funny one. If you haven't replace plugs, rotor, distributor lately then I'd say "yep" it's due.

 

[KRS]

Re: 3000 RPM and higher "slogging"

Well, followed the fuel line, it comes from tank to the separator (just replaced it with the Mercruiser product) then to the pump, then to the carb. No in-line fuel filter.<br /><br />At idle it runs high for 10 seconds, then slogs, chokes, almost dies, then slowly battles it's way back up the rpm range. Forgot to look at tach for idle rpm, but it sure sounded high. And, boat was VERY difficult to get into neutral from forward.<br /><br />I was going to pull dist cap, but it appears to need a special tool or can I just use a flat blade screwdriver?