No Spark on 1977 25 hp Johnson

[Navarre]

Motor was running great all day went to my favorite fishing hole turned the motor off to fish but when i tried to crank the motor it would not crank. No spark nothing. I was dead in the water untill another boater came by to tow me in. What could be the problem?<br /><br />1977 25 hp Johnson pull cord starter.<br />Motor was recently rebuilt and running great for about a month.

 

[OBJ]

Re: No Spark on 1977 25 hp Johnson

Welcome to iboats Navarre!<br /><br />When they die that fast, it's usually ignition related. But to make sure, do a spark test. The spark to each cylinder should jump a 7/16" gap with a hot lighting like spark.<br /><br />Just take a nail with the head cut off and stick in the spark plug wire. With insulated pliers, hold the end of the nail sticking out of the wire 7/16" away from a clean engine ground. Have a helper crank the engine. If the spark is there, you will see it.<br /><br />If the spark is good, take some premix fuel in a spray bottle and give the carb throat a couple shots. Crank the engine and see if it fires. If it does, you may have a fuel flow problem.<br /><br />You didn't post wether or not the engine is a remote or pull start engine.<br /><br />If it's a pull start, it'll have a push to stop button. Follow the wires back from the buttom and find the one connected to ground and disconnect it. Try to start. If it starts, the button is bad or you have a kill wire shorting out.<br /><br />Let us know what you find out from all the above.

 

[Navarre]

Re: No Spark on 1977 25 hp Johnson

Hey thanks for the info. I tried what you said and still no spark so im thinking what you said at first,ignition problem. I'm going to replace all electrical related items on the motor they all seem to have some age on them anyway. So if you know of any good web sites that sell that kinda stuff i would appreciate it.

 

[Chinewalker]

Re: No Spark on 1977 25 hp Johnson

Hi Navarre,<br /> I wouldn't bother replacing everything unless they are obviously going bad. More than likely it's something simple - maybe even just the kill switch or something. Replacing all items can be quite pricey, especially on a nearly 30-year old motor. <br /> To begin with - the coils are likely not the problem as it is unlikely that both coils went bad at the same time. Also not likel that the powerpack went bad, as usually it only goes bad on one cylinder at a time (in my experience) - although sometimes a bad ground on the powerpack can kill both cylinders at the same time. Try removing the bolt that holds the ground wire, cleaning it and the block in that area and seeing if it's a bad ground. <br /> That leaves the trigger and driver coil. Either could be the cuplrit. They're located on the armature plate under the flywheel.<br /> Good luck!<br />- Scott

 

[BoatBuoy]

Re: No Spark on 1977 25 hp Johnson

Navarre,<br /> I have a '77 35hp and last year I lost spark to both cyls. Turned out to be the powerpak. Just my experience. I got the new one from boatfix.com and I think it's the same as yours.

 

[Navarre]

Re: No Spark on 1977 25 hp Johnson

Hey thanks for all the info. Was looking at one of my coils and the wire looks like it had been fixed before so im sure that is one of the problems im having. I'm going to keep messing around with it and do some of the things you said scott untill i get it fixed. I'm also going to that web site and do some pricing there. The fish are calling my name got to get back in the water soon.