1956 15 HP Johnson won't run idle at shift

Joined
Apr 2, 2003
Messages
26
I just purchased a 1956 15HP Johnson motor, Model #FD-10 and Serial # 201356 with a presurized type fuel tank. The ower had it sit for 2 years. When I got it home I mixed new fuel and got it run after a couple attemps. After that it ran fine at start position and high speed but if I turned the handle to shift position the motor began misfire and stalled. There are two adjustable knobs (upper knob for low speed & lower knobs for high speed. I had tried to adjust low speed knob but could not get it idle at shift position. Anyone have experienced with this motor, please tell me what I should do to get it idle at shift position.
 

Yepblaze

Lieutenant Commander
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Jun 1, 2001
Messages
1,686
Re: 1956 15 HP Johnson won't run idle at shift

Service the magneto and get back to us.
 

dkondelik

Chief Petty Officer
Joined
Sep 10, 2002
Messages
643
Re: 1956 15 HP Johnson won't run idle at shift

i agree.<br />pull the flyweel, clean and reset the points. look at the coils. if they look to be covered in chalk or are cracked, replace them. there are still many sources of parts for these.<br /><br />I recently serviced a '55 for a neighbor. his motor had similar symptoms to yours. one of the plug wires was arking to the underside of the motor (easy to see at night).<br /><br />For future reference, you might want to look at:<br /> http://www.precisionserv.com/Outboards/Revitalization.htm <br /><br />and<br /> http://www.maxrules.com/fixtuneitup.html <br /><br />Let us know how things turn out<br /><br />Good Luck<br />HAVE FUN!
 

mattman

Cadet
Joined
Apr 1, 2003
Messages
10
Re: 1956 15 HP Johnson won't run idle at shift

Also check your cam roller that rides on the accelerator cam. This is located behind the carberator and can be easily found by rotating the shifter between WOT and Shift. Note whether the cam roller stays in contact with the cam when shifting into shift mode. If not then that would starve the fuel from the Carb. Just a thought from a fellow owner of a 15hp '56 Evinrude. I had a similar problem and replaced the roller.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 1956 15 HP Johnson won't run idle at shift

In addition to the above, also consider giving the carb a good cleaning. This involves a COMPLETE disassembly of the carb, but it's not too complicated. Make sure the float is set as per spec - absolutely level and even with the carb body when held inverted. Compressed air and carb cleaner are also necessary. Carb service should be covered in any general service manual you're likely to find in the local library, as would ignition service.<br />- Scott
 
Joined
Apr 2, 2003
Messages
26
Re: 1956 15 HP Johnson won't run idle at shift

My question is how to secure the flywheel when I put it back to engine and torque it to 45 ft.lb. I have a trouble to hold it before. Thank for any advises
 

Yepblaze

Lieutenant Commander
Joined
Jun 1, 2001
Messages
1,686
Re: 1956 15 HP Johnson won't run idle at shift

You can wrap a belt around it then grab both ends of the belt tight together against it with vice grips. Gives you a somewhat usable/funky strap wrench.<br /><br />I'd be using a pnuematic 1/2"impact gun for the nut without the need to hold the flywheel all that well, or at all.<br /><br />If I didn't have a impact gun I might ask my buddy to grasp the flywheel the best he can with both hands while I smacked the end of a long ratchet (breaker bar or wrench) with a moderate sized hammer. With each sharp blow on the wrench end the nut will tighten a bit more till it pretty much stops turning.
 
Joined
Apr 2, 2003
Messages
26
Re: 1956 15 HP Johnson won't run idle at shift

Here were what I did on the weekend:<br />I did pull the flyweel, clean and reset the points. The points & condensers look great. One thing I noticed that one coil are newer than the other. It looks like the previous owner had replaced on coil.(Does different coil age affect the spark and performance ?) I cleaned the caburator with engine caburator cleaner. <br />The motor was easily to start and ran much better when I put everything back but still stoped at shift mode. Then I checked the cam roller that rides on the accelerator cam. The cam roller did not stay in contact with the cam when shifting into shift mode. So the problem was at the cam roller. Look at the cam, it had been wore out a bit. So I put a tape to wrap around the roller to compensate for the wearness. It is just a quick fix. <br />Now one problem bothers me a lot is the engine vibrate a lot when runing at low speed. I found out that the flywheel was not balance (before and after I removed the flywheel out of the motor). ANY SUSGESTIONS HOW TO BALANCE THE FLYWHEEL !!!
 
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