Hello, new member here, hoping to hear some thoughts / recommendations on an idle issue I've been chasing.
I have a 100hp V4 w/ VRO on a Whaler Montauk. It is installed with a 30 gallon fuel tank under the captain's bench. I have a Parker-Racor filter/fuel water separator installed between the tank and engine.
The problem: The engine will stall if left to idle for more than a minute or two. It wil restart but usually with difficulty and usually w/ numerous starts & stalls. After successful restart it requires high idle (>2000 rpms) for a minute or more before it will engage gear w/o stalling out again. Once it's hot re-started successfully it runs fine at any given RPM other than idle.
The engine never cold starts on the first try, it will cough and sputter and require a few restarts but once cold started it idles fine and runs perfect at any given RPM. To me, it seems to blow more smoke than other 2 strokes I see on the lake both at start up and when running open, I always have a nice cloud on start up and with my hole shots and I notice a "vapor trail" when running open. The idling issue seems to occur when the engine is warmed to normal operating temp and when my fuel tank starts to get down around 1/3 to 1/4 full.
What I've done: I've replaced both the Parker-Racor and the inline fuel filter under the cowling. (I do both annually).
I went through and replaced all the plastic clamps on the fuel lines with stainless steel worm gear hose clamps (presuming I was pulling air into the fuel supply).
What's been recommended: Check my idle pins. I'm not proficient w/ carbs so I admit I haven't done this. It would seem to me that if it needed an idle adjustment it wouldn't idle properly after my initial cold start either. Am I wrong?
Rebuild the fuel pump. I've spoken with three different mechanics at three different marinas and they've all said they never had satisfactory results with rebuilds. Their advice is to replace with new OEM. The aftermarket rebuild kits are roughly $25 vs $600 for the new pump. I would hate to replace a $600 pump just to find out it didn't fix my problem and I've missed a simpler and/or less expensive repair.
Thoughts, advice? Thank you in advance!
are these metal carbs or plastic carbs.
does the motor sneeze at idle?
I don't think it does.
I think you are running rich...and need to lean out the idle mixture screws if they are metal carbs.
BUT if it does sneeze then you are running lean on one or two cylinders....hard cold start maybe just the way you are ttrying to start. Does this motor have a primer solenoid ( has a red lever)? if it does you'll need to test its functionality.
remove one hose from the primer solenoid (small line) , Pump the primer bulb hard and then turn the key to ON and push in....fuel should spit out. Turn key off
If it doesn't then solenoid is bad....and would cause hard cold start, with a lean sneeze
pump primer bulb hard again...NO FUEL shoud come out of either tiny hose from there.....if it does then solenoid gasket is faulty and dumping fuel into the intake manifold causing the hard cold start with excess fuel.
now if it is smoking excessively then you may have an air leak before the VRO pump, thus aerating the fuel giving the VRO less volume of gas and consequently riching up on oil.
make sure that you are NOT using worm clamps before the primer bulb or after , you should be using the snap clamps #6, on the oil line, #10 on the fuel lines (or even #8 if you can).....
at each connection slice off a piece of fuel line to get fresh rubber and re-clamp.
you could also inpect the vro's diaphragms...it is not hard to unscrew the air motor and the fuel pump side and see if either diaphram has a rip. Amazon has the pump for $368 or so, and the diaphragm kit is about 60+ for each side...plenty of you tube videos...
07-06-2017 10:14 - edited 07-06-2017 10:16
A number of things affect the idle of an engine. First make sure the compression numbers are within 15 psi from highest to lowest, the thermostats are warming up each cylinderhead to about 140°, the carb passagways are clean and sealed, the linkage and throttle plates are adjusted per the service manual, and the recirculation check valves are operational and their hoses and fittings are free and clear.
Decarbonizing the engine at least twice often helps free up sticky rings and varnished check valves.
The fuel pressure should be monitored with a quality gauge and the vacuum monitored at the fuel pump inlet fitting. Use a Tee and a length of clear line to check for air bubbles while the motor is running at all speeds.
Refer to the factory service manual for the specs and procedures.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.