1985 johnson 25h.p. wont idle goodi

[skippjack]

Need some help from the outboard gurus here. model # is j25rcos - electric start tiller. Purchased about a month ago and put it on my 1986 sea nymph 14r. Problem:
when i first tried this out in the ct river did not seem to idle good. a little shaky from side to side too. Tried to adjust low speed needle and made it worse. it would stall, but as soon as i hit the starter it would fire right back up. Now, I have to bury the throttle and still starts kinda hard. Right now at about 2 turns out. compression is 90 each cylinder warm with wot. This engine seems to run very well once i put it in forward and give it a little juice she seems to idle along pretty good at steerage speed, and when I throttle up to plane she goes real good. Planes the boat out nice sounds smooth and steady, have to back off on it even. No pops or pings or erratic behavior until I throttle down to steerage and it will stall out. I noticed that it seems real smoky at start up and idle. seems to be very rich and I now notice that I have a oil/gas green drip coming down the leg from under the lower cowl. I should note also that I have some sea foam in the tank. Im pretty sure I have a good mix at 50:1 unless I made a mistake I'm usually real careful and use a measuring cup for oil. Any advice out there? I'm starting to think this motor is a bum.

 

[Fleetwin]

As long as you have a good strong spark, it's time to thoroughly clean and rebuild the carburetor.

 

[skippjack]

Thanks , I was hoping one of you high ranking officers would say that. I was a little worried about compression readings as I have read posts with much higher numbers, but bigger engines prob. too. How can you tell if you have a GOOD STRONG spark. I've read you can by a spark tester but how do they work or measure the strength of the spark?

 

[jakedaawg]

You buy whats called an open air gap tester. It allows you to put the plug leads on it and hook it to ground. You adjust the air gap to 3/8ths to 7/16ths of an inch crank engine with plugs removed. You are looking for a nice clean bright blue arc with a snapping sound.

 

[skippjack]

Thanks, I am going to pick one of those testers up today

 

[skippjack]

okay, did the spark test tonite at almost dark. bottom coil has nice blue snapping spark at 7/16 - top coil would spark at first but was inconsistent and stopped sparking on a two to three second spin with the electric start. I saw something in the dark spark slightly on that coil itself so i pulled the boot and cleaned the contact with some emery cloth. re-tested that coil again and it jumped blue and snappy at 7/16 the only markings on the tester are a 10 and a 20 I was well beyond 20 and I used a piece of cut wire tie cut to 7/16" and put it between the contacts to achieve that distance. What do you think?

 

[jakedaawg]

if it runs good then fine, I would have a new wire and boot on hand though.

 

[skippjack]

Okay, here's the deal. I think I have a lazy coil. Fires pretty good when engine is cold, Once warmed up a little it fires when it wants. When it does spark pretty strong when she's cold, engine seems to idle much better. Will order a new one tomorrow. Also, I noticed that the number sticker on the bottom coil which is working good seems to be newer than the top one. Someone prob. changed the 1 coil and the bad one could possibly be the original, certainly older. Will let you guys no what happens. Thanks for the help.

 

[skippjack]

ok I changed that coil and it definitely idles better. Took it out today and did some crabbin. Needs some adjustment but does anyone have an idea about what would make the engine idle faster, too much in fact when I tilted the motor up to engage the shallow water drive and started it. I had to put it back in the normal running position as it was way too high of an idle. Racing in fact, and as soon as I put it down and started it again it was back to the normal idle speed.