Not sure if Temp gauge is working, SURE Tach isn't...(Merc 3.0L 140)

[drun_trucker]

So when I power the system all my gauges jump except the speedo and tach. I am new to boating so I'm not sure what temp a boat typically runs at (merc 3.0L 140)

I have read on how to check the wire for the tach, following the single grey wire from the soleniod. Well I could do that but there are NOT any gray wires going to the gauge when I get there. It looks like it may actually be orange but now sure...Also with regards to the temp there is a single wire coming from what looks like a place where the stat would be on a car. Is this the stat wire?

I know I'm missing info so please just shoot back and ask for what I forgot...I'm having a brain fart. SORRY

 

[Bondo]

Ayuh,..... Welcome Aboard,.... The tach is fed from the (-) terminal on the Coil, not a solenoid,......

'n Yes, the unit with one wire at the t-stat housin' is the temp sender,....

Ya oughta be seein' 160? to 170?,....

 

[drun_trucker]

Sorry it's been so long to respond.

Tach is bad, so I need to find one. Would like to get on to match the original on my Sea Ray (O.C.D.) or I will just buy a tach and speedo so they do.

And got the temp sending unit squared away. It was bad for sure. The only problem is I am still only running about 140*. If I open it up and hot lap the lake for 10-15 minutes it gets warmer but not anywhere close to 170*

Now I have an issue with stalling when trying to throttle. Engages gear fine, can accelerate a bit, then just past 1/8 throttle it wants to stall. Sometimes I can get jump to half throttle from idle and she bogs down but takes off then I can position the throttle wherever I want. I can NOT go from idle in gear to WOT, she stalls.

Idle screw is set as good as I can by sound (tach doesn't work) and the air/fuel screw on the bottom has been seated and turned out 1 1/4 turns as per factory setting settings. So I guess my question is can I keep turning the air/fuel screw out to solve the problem or am I chasing my tail there? The carb is CLEAN CLEAN CLEAN...upgraded to a new mechanical fuel pump and new filter. Fuel tank was removed and cleaned of debris, fuel lines replaced, alternator replaced (thought I might have been loosing voltage to the fuel pump)...Im ready to pull my hair out. Cap and rotor where new last year, points are clean. Not sure about the plugs and wires but they are getting replaced this week just because.

Im about ready to put 28 gallons of SeaFoam in it and see what happens. But before I go and do that, any suggestions?

 

[Alumarine]

You might have a 140 degree thermostat in there in which case your temperature would be fine.
Both of my 3.0 liters have the 140 thermostat, not sure what yours should be.

I might be the accelerator pump in the carb. With the engine off look down the carb while someone pumps the throttle.
There should be a spray of fuel when the throttle is advanced to full.

 

[drun_trucker]

I removed the throttle linkage from the carb and pumped by hand and its definitely getting fuel. If I can get it to get past the stall it opens up and runs great....I wonder if older plugs can have an effect? I may spring for some high performance ones and replace the wires too.