EngineerJohn
New member
Hi, I've got a 2017 Y15 SMHA outboard that has trouble starting.
The problem(s):
Stage 1: give it 4 to 10 pulls before it starts.
Stage 2: Once it does start, it immediately stalls, no matter how much throttle I give it (0 to full). It repeats this start-die cycle 3 times, reliably, till it actually gets started.
Stage 3: On the 4[SUP]th[/SUP] start-up, I goose the throttle to full open to keep it alive. During this stage if I bring the throttle down to idle it will die. Every time. I have to fully open the throttle for 15-20 minutes before it will be stable at low idle.
Stage 4: After 15-20 mins it has no trouble, high throttle, low idle, start, stop, whatever, but if I shut down the engine and it sits for 3 hours then the issue returns and we go back to Stage 1.
Weather here has been ranging from 50* to a warm 70* weather.
This is only really a problem because the outboard only goes into gear when it's in low idle, so I can’t even drive the darn thing while it’s warming.
I’ve tried a lot of different diagnostics and fixes (see list below).
The big question: What should I try next?
Diagnostic and testing recommendations are preferred to suggestions to outright replace parts.
----------------------------------------------------------------
Specs:
Yamaha Y15 SMHA
Year: 2017
4 Stroke
Transom height: S
Serial Number: 1050949
Model: 6AGK
History:
I got this outboard in March of this year. The PO warned me the motor took some time to warm up, but this seems kinda silly. Said he’d been running it all winter.
Things I've tried:
* Replaced all fuel lines & fuel bulb
* Carburetor rebuild * clean, complete with meticulous scrubbing & air hose blowout, jets were not blocked when I took the carb apart
* Pulled and tested the Primestart valve on 12 volts. It works as expected. Yes, the rumors are true; this outboard doesn't have a manual choke.
*Tired adjusting idle screw but if I set the idle high enough to where the engine doesn’t stall, then it’s too high to shift
* I'm starting the outboard in the throttle starting position, and I've tried every other throttle position during startup Stages 1-4 just for fun.
* No error codes
* Running 100% ethanol free gas
* Used seafoam fuel system cleaner
* Pumped fuel bulb while rev’ing down to low idle - no effect
* Checked for fuel leaks - none
* Replaced inboard fuel filter and axillary racore water-fuel filter
* Visually checked all relevant gaskets – they look good
* Checked for Vacuum leaks - nothing
* Pulled and cleaned spark plugs, checked for gap and spark – all good
* Visual inspection of air filter – clean as a whistle
* Read every darn forum post I could find, called three mechanics, and spent days working on the darn thing
* When I store the outboard at the end of the day, I always shut off fuel and let the carb run dry
Things I Have _Not_ Tried But Am Considering:
*Taking it to a Yamaha Service Tech
*Replacing the fuel pump (I feel I ruled that out by testing with the fuel bulb)
*Replacing the carb (that’s expensive!)
* Leakdown test (why would it have to do with the cylinders?)
* Connecting to a laptop and reading data while motor is running, hunting for clues
The problem(s):
Stage 1: give it 4 to 10 pulls before it starts.
Stage 2: Once it does start, it immediately stalls, no matter how much throttle I give it (0 to full). It repeats this start-die cycle 3 times, reliably, till it actually gets started.
Stage 3: On the 4[SUP]th[/SUP] start-up, I goose the throttle to full open to keep it alive. During this stage if I bring the throttle down to idle it will die. Every time. I have to fully open the throttle for 15-20 minutes before it will be stable at low idle.
Stage 4: After 15-20 mins it has no trouble, high throttle, low idle, start, stop, whatever, but if I shut down the engine and it sits for 3 hours then the issue returns and we go back to Stage 1.
Weather here has been ranging from 50* to a warm 70* weather.
This is only really a problem because the outboard only goes into gear when it's in low idle, so I can’t even drive the darn thing while it’s warming.
I’ve tried a lot of different diagnostics and fixes (see list below).
The big question: What should I try next?
Diagnostic and testing recommendations are preferred to suggestions to outright replace parts.
----------------------------------------------------------------
Specs:
Yamaha Y15 SMHA
Year: 2017
4 Stroke
Transom height: S
Serial Number: 1050949
Model: 6AGK
History:
I got this outboard in March of this year. The PO warned me the motor took some time to warm up, but this seems kinda silly. Said he’d been running it all winter.
Things I've tried:
* Replaced all fuel lines & fuel bulb
* Carburetor rebuild * clean, complete with meticulous scrubbing & air hose blowout, jets were not blocked when I took the carb apart
* Pulled and tested the Primestart valve on 12 volts. It works as expected. Yes, the rumors are true; this outboard doesn't have a manual choke.
*Tired adjusting idle screw but if I set the idle high enough to where the engine doesn’t stall, then it’s too high to shift
* I'm starting the outboard in the throttle starting position, and I've tried every other throttle position during startup Stages 1-4 just for fun.
* No error codes
* Running 100% ethanol free gas
* Used seafoam fuel system cleaner
* Pumped fuel bulb while rev’ing down to low idle - no effect
* Checked for fuel leaks - none
* Replaced inboard fuel filter and axillary racore water-fuel filter
* Visually checked all relevant gaskets – they look good
* Checked for Vacuum leaks - nothing
* Pulled and cleaned spark plugs, checked for gap and spark – all good
* Visual inspection of air filter – clean as a whistle
* Read every darn forum post I could find, called three mechanics, and spent days working on the darn thing
* When I store the outboard at the end of the day, I always shut off fuel and let the carb run dry
Things I Have _Not_ Tried But Am Considering:
*Taking it to a Yamaha Service Tech
*Replacing the fuel pump (I feel I ruled that out by testing with the fuel bulb)
*Replacing the carb (that’s expensive!)
* Leakdown test (why would it have to do with the cylinders?)
* Connecting to a laptop and reading data while motor is running, hunting for clues