Logo
FULL SITE MENU

Sluggish performance w 2002 40 HP 2 cycle engine

G

gkurtz

New member
"Just getting into this boatin

"Just getting into this boating thing, buying a used 2002 Boston Whaler Sport 130 with a Mercury 40HP 2 cycle (40ELPTO). The boat has been sitting for 2yrs. The gas was removed and run dry (we think). This spring I filled the tank with fresh gas removed the drain plug in the carb and flushed with clean fresh gas. The boat idles pretty good does load up a bit if left idling but it seems typical of my experience with 2 cycles. I am a fairly experienced mechanic both with car engines and small equipment. I did own and operate a business repairing small and midsized multi cylinder engines, but I have limited experience with outboards.
I took the boat out this weekend and it seemed underpowered. I did overload the boat by several hundred pounds. This included two heavy people, a spare battery, fishing gear, and a spare electric motor. I couldn’t get the boat on plane and the RPM’s wouldn’t go above 3500. The boat is spec’d at 5500. I bought the repair manual and checked the carb adjustments,linkages, timing etc., but couldn’t find anything wrong. I could rev it very quickly to 5000 RPM with no load in the driveway.
My question is could the overload condition cause the sluggish performance. It seemed as if I was plowing the water. I was pushing plenty of water behind. Any comments or suggestions are appreciated."
 
"HI Glenn,.sounds like a fair

"HI Glenn,.sounds like a fair bit of weight.if it only gets to 3500rpm,sounds like you have too much pitch on your prop.this why ive been suggesting PROPULSE props[im not an agent].ive used them,very good as u can adjust the pitch on the prop,very easily,gets your motor up to the recommended 5200-5500 band.worth a try.similar price to ali props.9.25am"
 
"600 pounds of boat, 175 pound

"600 pounds of boat, 175 pounds of motor, a couple batteries, people and gear/gas etc - so maybe 1200-1400 pounds - and trying to move that along with a 40.

I'm impressed that it made it to 3500...

But even if it was stored properly there could be some "cooties" in the system - I would decarb the motor for sure - try either some Seafoam or Merc's "Powertune" (just follow the directions on the can).

And as Ian suggests, if you are going to run "heavy" you are going to have to re-prop to significantly less pitch than you are currently running..."
 
It all makes sense. How do I k

It all makes sense. How do I know what my prop is. It appears to be factory however I couldn't find any information. The marking on the lower unit says 13X26.
 
"Should be a stamp on the prop

"Should be a stamp on the prop itself - usually between a couple of the fins - normally nothing more than a 17p or 19p etc.

If it's an OEM prop there is also usually a part number cast right into the outer hub - so if you look around the prop nut you may see a quicksilver number (48-123456 etc), and from that we can look it up..."
 
"if you didn't change the

"if you didn't change the prop since you owned it I would guess one of the carbs high speed jet is clogged. Clean them before its to late, no gas=no oil"
 
That 13X26 on the lower unit i

That 13X26 on the lower unit is the gear ratio (more commonly expressed as 2:1).

If there are no markings on the prop at all then it has most likely been changed. An OEM prop will have the quicksilver number stamped in it.

If there is no way to identify the prop you may have to take it to a "prop shop" where it can be quickly measured to determine diameter and pitch.
 
"Have to know for sure so I we

"Have to know for sure so I went out and bought a gasket kit. Couldn't find a complete rebuild kit locally so I'll have to be careful. Any surpises or issues with these carbs I should be aware of, or just disassemble, clean and reassemble."
 
Back
Top