Johnson 120HP

knuuttila

Cadet
Joined
Jul 21, 2003
Messages
23
Can anyone advise. I have two questions.<br /><br />1: My engine runs well but after about 5 hrs use one of the cylinders stops firing(always the same one) and I have to take the sparkplug out, clean it and then it runs fine again for a few hours, then I have to do it again. Whats causing this.<br /><br />2: Occasionally the overheating horn sounds, (a continuous sound)but there is plenty of water coming through the engine and it,s only warming to the touch. I don,t think it is actually overheating but when the horn sounds, it is a worry. Any suggestions anyone.<br /><br />Thanks for your help,<br /><br />Brian
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Johnson 120HP

Knuuttila...can you give us a year or model number?<br /><br />If one plug is fowling out, it may be caused by a weak spark. Check that the spark will jump a 1/2" gap with a hot lighting like white spark.<br /><br />The continuous horn tone may also be telling you of a restricted fuel supply if it's a more up to date engine. Check your fuel supply hoses for kinks and restrictions. Fuel tank vented OK?<br /><br />Let us know...thanks.
 

knuuttila

Cadet
Joined
Jul 21, 2003
Messages
23
Re: Johnson 120HP

Thanks for your reply. It,s a 96 model. I,ll try a new set of plugs and check the fuel system is not obsttructed anywhere <br /><br />Rgs<br /><br />Knuutila
 
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