No fire from 1972 50h.p. Johnson

I have a 1972 50h.p. Johnson ,model 50ESL7, ser. no. E3643064 and I'm getting no fire at the plugs. I've had the motor several years. When I bought it, there was what appeared to be something dripping down the motor case(like a dried resin) from under the flywheel. It was hard and dry and the motor ran fine for the dozen or so times it's been in the water. I've tried disconnecting the black/yellow wire at the power pack but no luck. Motor turns over but no fire. Thanks for any help.

Re: No fire from 1972 50h.p. Johnson

Check your plugs and make sure you are getting spark to them. Pull them and see if they jump 1/2 inch to the block. If they don't you probably have a bad ignition coil.<br />Are you getting fuel to them? Are they wet? If not pull your carb and rebuild it. Chances are at that point your float is stuck or your high speed jet is clogged. Replace the float/needle vavle/ needle vavle seat. Clean the high speed jet Thoroughly.

Re: No fire from 1972 50h.p. Johnson

Fuel to plugs is no problem. Neither plug has fire. I'm concerned that the "dripping resin" from under the flywheel is right where the "pickup coil" would be located( forward part of stator, where the timing pointer is located on the engine block ), although I suppose it's not unheard of for both coils to "drop dead" at the same time! Thanks for your input

Re: No fire from 1972 50h.p. Johnson

P. Luttrell.... The dripping that you see, that ran down from under the flywheel is caused by a melted down stator assy. The stator consists of two areas... the smaller coils pertain to the charging system, and the two larger coils are connected in series and are the beginning of the ignition system.<br /><br />Those two larger coils develop and supply approximately 300v AC to the powerpack. When they melt down, the voltage drops, and keeps dropping, and eventually there is no output to the powerpack, hence no ignition. On that model, the melt down failure is usually due to a failed rectifier.<br /><br />When a rectifier fails, the charging system portion of the stator is not able to have its AC power converted to DC power, and have it forwarded to the battery. Therefore that power simply sits there at the stator and cooks with nowhere to go.... and it melts down.<br /><br />The rectifier failure, having it short out, is usually due to someone at one time hooking up a battery or a battery charger backwards. Rectifiers will not tolerate reverse polarity at all. The rectifier can also be damaged by running the engine without a battery being in its system.<br /><br />The stator is OMC part number 581232. If you have a problem locating one locally, I have one left in my remaining stock. ReevesJ32@aol.com

Re: No fire from 1972 50h.p. Johnson

hey joe! sounds like my problem too!<br />i found a used stator,havent recieved it yet.<br />incase the rectifyer is bad too, where is it located?<br />thanks, larry

Re: No fire from 1972 50h.p. Johnson

Joe, thanks for the details. I've got your e- mail address, so I'll contactyou about particulars on the stator you have for sale. Also there was another post asking about the rectifier location I might want to look into that also. No use in frying another stator!! Thanks again, Bud.

Re: No fire from 1972 50h.p. Johnson

The rectifier location? Find the terminal board. Close by that board will be a metal object with a round tower like appearance. It's base will be sort of triangular shaped. It will have three wires leading from it to the terminal board, a yellow, a yellow/gray, and a red wire. That's the rectifier. Some rectifiers also have a yellow/blue wire. The method for checking a rectifier is as follows.<br /><br />Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction. <br /><br />Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other. <br /><br />Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires. <br /><br />Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier.

Re: No fire from 1972 50h.p. Johnson

TO Joe Reeves: thanks for the help. I received no spark with the black/yellow wire on or off. This indicates a powerpack if I read your info correctly. Is this a difficult job. I am a fair backypard mechanic. Wayne

Re: No fire from 1972 50h.p. Johnson

Shouldn't be. Just a few bolts and some wires to plug together.

Re: No fire from 1972 50h.p. Johnson

fireman 757 said:

Check your plugs and make sure you are getting spark to them. Pull them and see if they jump 1/2 inch to the block. If they don't you probably have a bad ignition coil.<br />Are you getting fuel to them? ]

my 1991 200hp johnson fire comes and goes, do you think my ignition coil is going bad and is the ignition coil different than the coil packs. if so where is the ignition coil located at on the my engine.

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Re: No fire from 1972 50h.p. Johnson

there are 6 pages here, find your motor "http://www.boatpartstore.com/page28.asp"