Have used this motor for 7 years with no issues on a fresh water sailboat ... usage is low (minimal 15 Gallons of fuel per season) ... motor nears hull speed at 50% throttle ... marginal prop depth limits higher throttle except under calm conditions so rarely run at greater then 50% throttle
Issue ... the motor was running smoothly at about 30% throttle when it suddenly sounded like it throttled back (when motoring we lock the throttle) this wasn't a case of the lock disengaging ... within seconds the motor resumed it's previously set RPM ... thinking the almost empty fuel tank might have picked up some moisture (had been very hot then humid) I decided to changed over to our full tank. The behavior didn't improve and it actually started getting worse to the point where it was more like choking response at any percentage of throttle above idle
We tried going out again on another occasion but encountered the same issues plus had a real struggle to get the boat back in under windy conditions without consistent power it is easy to loose control of this boat
At that point I:
- dumped and refilled the empty tank with 91 octane 0% Ethanol
- drained the carb via it's drain screw
- cleaned the needle/jet valve
- checked the plug wires
- visually inspected the fuel filter for cracks or contamination (clear filter)
- checked the carb fuel (looking for any signs of water)
- checked the engine oil (looking for any contaminants)
- checked temperature
- checked intake and exhaust ports
- checked all the fuel linkages for choke and throttle
- ran up the motor for 30 minutes both in an out of gear tied up to dock with no repeat of the issue
Yesterday because it was calm we decided to try our luck ... the motor started fine and idled fine for several minutes before we ventured out ... minutes later we were again back in this Extreme Choking mode.
- the motor almost behaves like it has the choke wide open (confirmed that choke was physically in run position)
- aggressive throttle up down can momentarily restore normal run condition but then quickly reverts to this intermittent CHOKING mode.
- some throttle settings appear to do better then others
- so far the motor hasn't actually died during this condition it just stays running roughly
- on all three outings we were able to limp back in under almost idle power but that was touch and go on windy day ... yesterday was more so as idle was sounding like it would die any moment
I suspect idling is getting worse due to continued running of the motor in this strange mode (the plugs are possibly getting fouled) ... I haven't check the plugs yet because they are difficult to get at with the boat in the water.
Looking for suggestions?
Thanking you in advance for your time.
Issue ... the motor was running smoothly at about 30% throttle when it suddenly sounded like it throttled back (when motoring we lock the throttle) this wasn't a case of the lock disengaging ... within seconds the motor resumed it's previously set RPM ... thinking the almost empty fuel tank might have picked up some moisture (had been very hot then humid) I decided to changed over to our full tank. The behavior didn't improve and it actually started getting worse to the point where it was more like choking response at any percentage of throttle above idle
We tried going out again on another occasion but encountered the same issues plus had a real struggle to get the boat back in under windy conditions without consistent power it is easy to loose control of this boat
At that point I:
- dumped and refilled the empty tank with 91 octane 0% Ethanol
- drained the carb via it's drain screw
- cleaned the needle/jet valve
- checked the plug wires
- visually inspected the fuel filter for cracks or contamination (clear filter)
- checked the carb fuel (looking for any signs of water)
- checked the engine oil (looking for any contaminants)
- checked temperature
- checked intake and exhaust ports
- checked all the fuel linkages for choke and throttle
- ran up the motor for 30 minutes both in an out of gear tied up to dock with no repeat of the issue
Yesterday because it was calm we decided to try our luck ... the motor started fine and idled fine for several minutes before we ventured out ... minutes later we were again back in this Extreme Choking mode.
- the motor almost behaves like it has the choke wide open (confirmed that choke was physically in run position)
- aggressive throttle up down can momentarily restore normal run condition but then quickly reverts to this intermittent CHOKING mode.
- some throttle settings appear to do better then others
- so far the motor hasn't actually died during this condition it just stays running roughly
- on all three outings we were able to limp back in under almost idle power but that was touch and go on windy day ... yesterday was more so as idle was sounding like it would die any moment
I suspect idling is getting worse due to continued running of the motor in this strange mode (the plugs are possibly getting fouled) ... I haven't check the plugs yet because they are difficult to get at with the boat in the water.
Looking for suggestions?
Thanking you in advance for your time.