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Hard starting 25hp model year 2000

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old johnson guy

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2000 model Johnson 25hp electric start long shaft tiller with very low hours that is very cold blooded. Have tried most every combination of priming, but seems to flood no matter what. Had a carb kit installed by retired mechanic, but no change. Runs very well at speed, lots of power, but even after wot runs across the lake, runs poorly at low speed and sometimes stalls. Starts right up when warm. New plugs and fresh gas every season. Operator error? I am not a mechanic. Ready to trade off for a 4 stroke.
 
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2 or 3 cylinder motor ?-----Please describe your procedure for starting this motor in detail.------Does the primer bulb on the hose go hard ?----Is the battery fully charged ?-----Have you ever cranked and cranked and possibly damaged the starter ?-----There is no such thing as a " cold blooded motor " in my opinion.
 
old johnson guy said:
2000 model Johnson 25hp electric start long shaft tiller with very low hours that is very cold blooded. Have tried most every combination of priming, but seems to flood no matter what. Had a carb kit installed by retired mechanic, but no change. Runs very well at speed, lots of power, but even after wot runs across the lake, runs poorly at low speed and sometimes stalls. Starts right up when warm. New plugs and fresh gas every season. Operator error? I am not a mechanic. Ready to trade off for a 4 stroke.
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It is a 2 cylinder. The primer bulb goes hard. I have tried any where from no pumps on the choke/primer knob, to up to 3 or 4 full pumps, also one pump then hold the knob extended out, two pumps, hold the knob out etc. The starter appears to be working properly without disengaging the flywheel. Battery is fully charged. Seems like the engine floods and then takes a lot of turns with the starter to clear out the fuel, but not priming does not work either. One more thought, it is very shallow where I launch the boat, so motor is in shallow drive position. Could the gas be getting past the floats in this position and flooding the motor? Could try rowing out to deeper water and putting motor all the way down before pumping up the bulb.
 
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The shallow drive position does not help on initial start-up.Are you advancing the " throttle only " lever for start-up ?
 
For starting you rotate the throttle handle till it hits the nuetral interlock.-----The " start position " on the handle is only a rough guess at best.-----If a motor like yours that has been built for 30 some odd years does not start properly then there is a problem----So there is something wrong with the motor or the starting procedure needs review.---See a dealer or shop for some pointers.
 
kimcrwbr1 said:
Have you adjusted the slow speed needle. Count the turns in clockwise until lightly seated and then turn it out 1 1/2 turns counterclockwise preadjust. In a barrel of water or out on the lake bring the engine up to normal temp and idle the motor down in forward gear then turn the needle out until the motor coughs then slowly turn it in until it stumbles then back out for a nice smooth idle. When your adjusting it turn 1/8 turn at a time and wait 20 seconds for the crankcase to respond. Once you find a nice smooth idle turn the needle 1/8 turn rich to protect the motor and just leave it there.
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I have not made any adjustments to the carb, so I will give that a try. Thanks for the procedure.
 
racerone said:
For starting you rotate the throttle handle till it hits the nuetral interlock.-----The " start position " on the handle is only a rough guess at best.-----If a motor like yours that has been built for 30 some odd years does not start properly then there is a problem----So there is something wrong with the motor or the starting procedure needs review.---See a dealer or shop for some pointers.
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I will try moving the throttle handle as you suggest since it is just a range of position. Thanks to everyone for the suggestions.
 
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