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johnson sea horse mag flash cd

L

larryjohnson

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i have an issue with my johnson 115 horse magflash cd motor. when muffs are on it will start and run fine. when you take it to the lake and launch it it will start and high idle, but when you lower the high idle lever it will die and then will have a no crank no start issue. carbs have been rebuilt and plugs have been changed and all gas has been drained, the only number i can find on engine is 115txl78. any help would be appericiated
 
ill post them up tomorrow, just didnt think it would be a compression issue due to a no crank no start. you can put this thing in the water and it will start and run on high idle. put it in gear to idle and it dies. go to restart nothing just clicking. load boat back on trailer pull up ramp. she will fire up no issue. back back down into water, fires right up let it sit and run on high idle for 10 mins go to drop in gear dies. go to restart just clicks like battery is dead.
 
Take starter apart for inspection.----Load test the battery.-----Inspect battery cables.---But do the compression test first !
 
Absolute #1 reason for "just clicking" is poor battery cable connections. Remove and clean them shiny bright.and reinstall tightly. Don't just look at them or wiggle them---clean them.

#1 reason for stalling at idle in the water is throttle idle speed set too low. That is, assuming there is nothing wrong with the motor.
 
standing at rear of boat

left top 122 right top 90

lefter lower 120 right lower 121

not sure of cylinder orintation so ill list as i pulled compression check. compression is low on one cylinder. what would the possiblity be maybe just a bad head gasket. since motor was just proffesionally built 2 seasons ago and engine has always had a proper 50.1 fuel mix. did have to put a impeller in it last season due to impeller failure. also had a guy tell me thermostat can cause low compression.(not sure about this). im no outboard or 2 stroke mechanic by no means but i am a diesel mechanic.so not mechanically ignorant.
 
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ok guys pulled the head and the piston looks like its been beat to pieces with a nut. also the cylinder wall has some excessive scarring.


so new question. paid 2200 for a rebuild 2 summers ago. are these engines sleeved like a diesel or do i need to get the block bored. if it can be re sleeved can i just sleeve it put a new piston and rod in it???? or does it need a total rebuild again???? or trash this engine and buy new???? Please Help???????
 
Classic failure of piston rings I would say.--------Your location ?-----They can be rebored.----Was it not bored 2 years ago ??----Year / model # of your motor ?
 
rings look good its just the top of piston and edge of piston and inside of head. knoxville tn. no it wasnt bored therfe was nothing wrong with the engine i just had it freshened up and they just honed the cylinders. 1978 115txl78c
 
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