Johnson kicks into gear when turned off????

[tautog27]

I have a strange question, My 72 Johnson 50hp kicks like a mule when I shut it down. It will actually make my boat lurch foward a bit. The motor runs like a top, starts 95% of the time, and even idles great. When it shuts down it stops almost instantly, it doesn't diesl, but it feels like your throwing it into gear with the gas full on. Any ideas? Thanks, Ross

 

[petryshyn]

Re: Johnson kicks into gear when turned off????

I take it its electric shift. There is a diode assembly that holds it in neutral until engine shuts down. The charging stator supplies the current necessary for this function. Its a three wire device under the hood....its wired directly to the terminal strip.<br /><br />good luck!<br />

 

[tautog27]

Re: Johnson kicks into gear when turned off????

Schematic, as always thanks for your help.<br /><br /> I've been reading the Clymer shop manual, and sort of have a grasp on this function, of course the manual looks nothing like my motor. I have a junked evinrude with a similar positive or maybe negative diode, or heck maybe its the rectifier. I was wondering if the two are interchangeable. If not where might I buy one, I'm not even sure what to call it. The two numbers on the thingy's are VARD R315 7211 and VARD R315 7744. I don't know of if any of my bable will make any sence to anyone, but your help would be greatly appreicated. Thanks, Ross<br /><br />Keep the prop wet and the motor dry.

 

[petryshyn]

Re: Johnson kicks into gear when turned off????

This is all I got for info on the diode assmy (blue) Its connected to the charge stator as well as the rectifier. Sorry, The numbers mean nothing to me.<br /><br /><br />Good luck!

 

[tautog27]

Re: Johnson kicks into gear when turned off????

Schematic, I'm not sure if this will help, but thankyou so much for taking your time, to try to give me a hand, I can't thankyou enough!!! Thanks again, Ross

 

[seahorse5]

Re: Johnson kicks into gear when turned off????

Schematic's schematic is a big help on visualizing the circuits.<br /><br />Your motor has a hydraulically shifted gearcase that is activated by electrical solenoid valves. With no power or hydraulic pressure, it is spring loaded into fwd. gear. When you start the motor in neutral, 12v goes to the green shift wire to close a valve and build up pressure to move the clutch dog away from fwd gear, putting it in neutral. When you turn the key off, the green wire loses 12v and the solenoid retracts and the clutch dog "bangs" into fwd.<br /><br />The stator generates AC current that is changed to DC battery charging current by the rectifier assy. The diode assembly hanging there, changes AC current to 12v DC to keep the green neutral wire energized while the flywheel is still spinning down. If the rectifier is shorted, the stator not generating, or the diode assembly is faulty, the green neutral wire will not get 12v after the key is turned off. A broken or corroded connection or wire can do the same thing.<br /><br />I hope this explains how the system works.

 

[petryshyn]

Re: Johnson kicks into gear when turned off????

One thing I forgot to mention.....is the charging system working? If the charging system rectifier is bad, unit will jump into gear when key shut off. Check both the charging rectifier and the shift diodes....<br /><br />Good luck!

 

[ajp]

Re: Johnson kicks into gear when turned off????

Do you need a manual that makes sense for you motor,<br /><br />I have the original factory service manual for a 1970 50hp that is basically the same motor as the 1972. Detail pictures, drawings, and specifications for your motor and controls. Not a generic manual for multiple years and horsepowers. In my opinion those CLymer and Seloc manuals are a waste of money for anyone serious about their motor. <br /><br />Another thing you might think about is the type of lower unit oil you are using. The electric shift motors take a different type of oil. They do not work right using the modern 90w sold at Walmart. <br /><br />$9.99 + shipping of $2.00 <br /><br />If you are interested, email me at arlan@pldi.net.<br /><br />Arlan

 

[tautog27]

Re: Johnson kicks into gear when turned off????

Everybody,<br /><br />Thanks for all of the help!! I found the diode today, which was nicely tucked in behind the power pack, out of sight. Schematic, I couldn't have find it with out you, thanks man. The local boat shop here in Raleigh, is charging 65 bucks for a new after market diode, hopefully that's what's wrong. The guy instantly told me it was probably the oil pump in the lower unit, he said for a $120 he'd tell me for sure, I think I'll try every thing else first. Again, thanks everyone for all of your help, hopefully we will get to the bottom of this. Heck I'm having a blast learning about all of this anyway! Thanks, Ross

 

[tautog27]

Re: Johnson kicks into gear when turned off????

ajp,<br /><br /> Will you take a check? I don't need it today, but the way things are going, it won't be long until I do. I have to agree with you that the Clymer manuals stink! Even though it says on the cover that my year and model are included, there is alot left out, including that all important wiring diagram!

 

[petryshyn]

Re: Johnson kicks into gear when turned off????

Hey Raleigh Wood:<br /><br />Don't be buying that overpriced diode assmy until you prove its bad. Do you have an ohm-meter at your disposal?<br /><br />

 

[tautog27]

Re: Johnson kicks into gear when turned off????

Nope, but I can probably get my hands on one. Aren't those thinks pretty expensive? I figured just buying the diode would be cheaper than an ohmeter? By the way, do you think that 65 bucks is too much for the diode? Sorry, I probably should be paying you by the hour at this point. Thanks again, Ross AKA "The Man With Too Many Questions"

 

[petryshyn]

Re: Johnson kicks into gear when turned off????

Hi <br />Ohm-meters are a "dime a dozen". If you don't want to purchase one, atleast take the diode assembly off the engine and have a mechanic check it for you. Be sure you label the leads or draw on paper where they came off of. Hate to see you buy one, only to find other problems! Checking this puppy is where to start.<br /><br />Good luck!

 

[tautog27]

Re: Johnson kicks into gear when turned off????

Schematic,<br /><br />I just talked with a friend who happens to be an electrical engineer, he said he'd be happy to check it out for me! I'll keep ya'll posted. Thanks, Ross

 

[CAPTBLACKSMARINE]

Re: Johnson kicks into gear when turned off????

BEFORE YOU BUY ANY PARTS YOU SHOULD PROBALY KNOW THAT THE MOTOR YOU HAVE IS SUPPOSED TO SHIFT INTO FORWARD GEAR WHEN THE IGNITION IS TURNED OFF THIS FEATURE WAS BUILT INTO THE MOTOR SO IF SOMETHING WENT WRONG WITH THE ELECTRICAL FUNCTIONS OF THE GEARCASE WHILE OUT ON THE WATER THE MOTOR WOULD LOCK INTO FORWARD GEAR AND YOU COULD COME HOME ATLEAST BACK THEN THE ENGINEERS REALIZED NO MATTER HOW GOOD THE DESIGN WAS IT COULD STILL FAIL YOU ARE RIGHT ABOUT THE MANUALS BUY THE FACTORY MANUAL NOT THE AFTER MARKET AND AT THAT PRICE YOU CAN'T GO WRONG THE FACTORY MANUALS FOR YOUR MOTOR ARE GOING FOR $30.00 PLUS IF YOU DON'T BUY THE ONE OFF HERE WHICH IS THE BETTER DEAL YOU CAN GET THEM FROM KEN COOK CO.OR GO TO KENCOOK.COM GOOD LUCK

 

[petryshyn]

Re: Johnson kicks into gear when turned off????

CAPTBLACKSMARINE:<br /><br />Interesting....so whats the purpose of the the diode assembly?

 

[tautog27]

Re: Johnson kicks into gear when turned off????

Capt. Black,<br /><br />I realize that the drive shaft/prop is spring loaded to engage automatically into foward when not in reverse or neutral. However, aren't the shift diodes supposed to hold the trans in neutal until the flywheel stops turning? At any rate thanks for the tip on the manual, you sure called that right! Thanks, Ross

 

[CAPTBLACKSMARINE]

Re: Johnson kicks into gear when turned off????

SCHEMATIC IF I REMEMBER RIGHT THE DIODE WAS JUST TO KEEP THE MOTOR FROM LOCKING INTO GEAR TO QUICKLY WHEN THE MOTOR WAS SHUT OFF BUT NOT TO KEEP IT FROM GOING INTO GEAR AT ALL BUT ALL OF THESE I HAVE SEEN EVEN WITH THE DIODE WORKING WOULD STILL LOCK IN GEAR BEFORE THE MOTOR STOPPED TURNING COMPLETELY

 

[petryshyn]

Re: Johnson kicks into gear when turned off????

After a good explaination from a very smart man(Clanton) that was my take on it as well. It will delay the engagement up to a point. Obviously as the motor slows down next to a halt, the stator output is low and current is too low to maintain neutral. If the L/U engages the instant the key is shut off, it suggests the diodes or stator are not doing their job. Our friend complains of it kicking in hard which certainly suggests that. One other factor is the rectifier for charging. If it has failed open, it will also prevent the shift delay. These failures are common amongst battery cables being reversed by accident. Thats why I'd recommend checking the diodes and rectifier and even stator output, before any purchasing.....<br /><br />Good luck!

 

[tautog27]

Re: Johnson kicks into gear when turned off????

Thanks guys,<br /><br />I should get a chance this evening to have my friend check out the diode, I think I'll try to get him to check the rest if possible. So, I guess that I shouldn't look for a completely smooth stop? Thanks Ross