Johnson woe

borneoman

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Feb 7, 2003
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5
Any assistance gratefully recieved<br /><br />i have a johnson 225hp bought new in 2001 which has developed a fault.<br /><br />The alarm sounds continously<br />and the motor (which only has eighty hours on it) will only rev to 3000 revs and only fires on one side this problem only develops after about two minutes running.<br />The fuel filter was clean the water pressure is good the plugs are new.<br /><br />Does anyone have any ideas? :confused:
 

Joe Reeves

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Feb 24, 2002
Messages
13,262
Re: Johnson woe

Borneoman..... Your engine has what is called a S.L.O.W. feature. When the engine overheats, that feature engages which knocks out the ignition on one bank, dropping the rpms down to approximately 2500 rpm. Sounds like you have a water pump failure or/and a water circulating or thermostat problem.
 

borneoman

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Feb 7, 2003
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Re: Johnson woe

Thanks Joe Reeves<br /><br />How do i go about checking the water circulation and the thermostat .<br />When the engine is running i get a good water pump discharge.
 

Joe Reeves

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Feb 24, 2002
Messages
13,262
Re: Johnson woe

Borneoman.... With the thermostats closed, you would still get a good water outlet pressure flow even if the water pump was brand new.<br /><br />From what you've said in your last post, it's possible that you've picked up some debris and have somehow ended up with it logged in the water passageways. If this is the case, I'd suggest that you remove the lower unit to inspect the water pump. Also remove the thermostats so that you can flush out the system (forwards and backwards) via the water intake tube and the thermostat housing areas.<br /><br />The thermostats open at approximately 143°, some slightly higher... possibly 148°. They can be checked by removing them and testing them in hot water. However, of course, you would need some type of measuring device to make sure that the water is the proper temperture.<br /><br />Note that your problem is usually due to a water pump that is on the verge of failing but has not quite reached the point of total failure... just at the weak stage. Good Luck....
 

borneoman

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Feb 7, 2003
Messages
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Re: Johnson woe

Hi <br /><br />Have now changed the powerpack and all was fine for five minutes now the lower plug is oiling up and revs have dropped from 5500 to 4000,<br /><br />I accidently put 25litres of premix 25:1 into the 200litre tank could this be the problem?<br /><br />If not how do i stop the lower plug oiling up?<br /><br />Cheers Borneoman
 
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