Plugs 65 HP Johnson, 1972

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Just purchased Johnson 65 HP all indications are it is a 1972 - 1973. No numbers to properly identify it. When I look it up on the Johnson parts site it shows a Champion UL77V. The plugs that were in it are QL77JC4. When I bought new plugs I bought the ones that were in it. QL77JC4. There book had them gaped at 0.30 When I looked up the others (UL77V) I think it said 0.35. Can someone tell me the difference. It runs ok, need to clean the carbs. Should I buy other plugs, regap the ones I just bought?? Thanks for the help. Leont
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Plugs 65 HP Johnson, 1972

QL77JC4 is an alternative plug as the UL77V, proved not to be the best. gap them a .030.
 

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Re: Plugs 65 HP Johnson, 1972

Thanks for the fast reply! Have a lot to learn about outboards. Leont
 

jay_merrill

Vice Admiral
Joined
Dec 5, 2007
Messages
5,653
Re: Plugs 65 HP Johnson, 1972

I've been running L77JC4 plugs in my 1972 Johnson 65hp motor with good result. They were put in at my local OMC/BRP dealer's suggestion.

The QL plugs suppress RFI, which can be important in later OMC outboards that have VRO or optical ignition. Some say that the older motors don't need the QL plugs, but some prefer them. According to the Champion spark plug site, the logic in using the QL plugs in motors of your vintage, is that CD type ignitions produce less voltage and that the use of non-inductive type plugs, may cause poor performance and misfiring.

I have been using L77 plugs for about three years and have not experienced the poor performance and misfiring that Champion claims to be an issue. That said, they are not specific about which CD type of ignition that they are talking about. I guess my take on this is that the CD ignition systems that are most likely the ones in question, are the battery CD systems, not the magneto CD systems.

If any of the members have information on this, I'm sure the OP will appreciate it, as will I.


PS: If you motor is a 1972, it will not have a tilt tube built into the transom bracket. It will also be an "Anniversary Edition" motor (Johnson, 50 years) and will have a placard on the front of the cover with that info on it. The motor will also be hydro-electric shift, rather than hydro-mechanical shift.
 

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Re: Plugs 65 HP Johnson, 1972

Not sure of all the terminology. Mine has a piece in the transom that comes down for tilt, however transom is different, has 75 Hp on plate. Also difficult to ID because the case and the motor do not match. Someone switched them out. Case has an opening for a manual choke and the motor is elec. choke. The marina where I get the parts thought it was a 72 or 73. Unclear on hydro elec. vs hydro mechanical. I assume mine is hyro electric, has a 3 button shift.
Thanks for all the information. Leont
 

jay_merrill

Vice Admiral
Joined
Dec 5, 2007
Messages
5,653
Re: Plugs 65 HP Johnson, 1972

Sounds like you have a hybrid motor. If your transom bracket is from a later motor, you probably have a tilt tube for your steering cable. If the powerhead is a 1972, you will have magneto CD ignition. The midsection and gearbox may be from a 1972 also. That would make it a hydro-electric motor.

You can tell if you have magneto CD ignition because you will see a silver or black box that is about the size of a pack of cigarettes(except a bit more narrow), on the starboard side of the powerhead. This is called a powerpack. You will also have three ignition coils mounted on a rack behind that. If the motor is an earlier, battery CD ignition motor, it will have a box that is basically square and is called an amplifier. The motor will also have only one ignition coil. The 1972 motor will also have a yellow plug in the engine compartment, while the older motor will have a black plug.

A hydro electric shift, which is indeed what you have if you have a push button shift, is a shifting system that uses electrical circuits to activate a couple of solenoids in the gearbox. The gearbox also has a pump in it that uses the gear oil to create hydraulic pressure. It is that pressure that is used to shift gears and the previously mentioned poppet valves, direct the flow of fluid as needed.

The hydro-mechanical shift works much the same way, but uses a mechanical connection (shift rod) to the poppet valves, instead of an electrical one.

If you have push button shift, it is an Evinrude control box. The Johnson version has a single lever throttle/shift, with a small warmup lever. Take very good care of your control box, because the shift switch is no longer available, unless you happen to find a used switch that still works.

Your motor should have a manual choke in addition to the electric choke - I suspect you are just missing the parts for the manual choke.

If you can take some pics of this motor and post them here, we can get a better ideaa of what it is. That will enable us to better answer your questions.
 

Coral Reefer

Cadet
Joined
Sep 1, 2008
Messages
9
Re: Plugs 65 HP Johnson, 1972

I don't mean to hijack this thread but I also have a 1972 65hp Johnson. I took it out fishing today. It's been a couple years since I've had it out. I seem to remember feeling and hearing it shift before. Today I did not feel or hear it shift a single time. It also doesn't seem to be running at full rpm. I't does run smoothly and the carbs have been cleaned out. Shouldn't I hear or feel it shift? Also could it be stuck in 2nd or high gear maybe? It doesn't take off as well as it should and seems about 8-10 mph slower. Sorry again but you appear to understand this motor much better than I do Jay.

Thanks, Jeff
 

Coral Reefer

Cadet
Joined
Sep 1, 2008
Messages
9
Re: Plugs 65 HP Johnson, 1972

After more reading, Was I completely confused? Does the shift system just shift from rev. to neut. to for.? If so, mine is working fine. I could swear it used to shift from low to high but that doesn't make sense.:confused:
 

jay_merrill

Vice Admiral
Joined
Dec 5, 2007
Messages
5,653
Re: Plugs 65 HP Johnson, 1972

Yes, you are hijacking this thread and no, you don't have "2nd gear." If you do a thread search on hydro-elecric shift systems, you will find many entries on the subject. I think you'll find them to be very helpful.
 

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Re: Plugs 65 HP Johnson, 1972

Capt. Merrill,
It appears I have the magneto CD ignition, fits all above. The one I am looking at is battery CD ignition. It has one coil. Will that stator and rectifier work with mine? I noticed you said it was older. Thanks again! Leont, HN
 

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Re: Plugs 65 HP Johnson, 1972

Capt. Merrill,
It appears I have the magneto CD ignition, fits all above. The one I am looking at is battery CD ignition. It has one coil. Will that stator and rectifier work with mine? I noticed you said it was older. Thanks again! Leont, HN
Also compression is about 118 on all 3 cylinders, is that too bad? I noticed they should be 130, (may have been my methodology).
 

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Re: Plugs 65 HP Johnson, 1972

pictures attached, I hope. Leont
 

Attachments

  • Port 65.jpg
    Port 65.jpg
    22.6 KB · Views: 0
  • Starbord 65.jpg
    Starbord 65.jpg
    24.7 KB · Views: 0

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Plugs 65 HP Johnson, 1972

pictures attached, I hope. Leont

Pictures are Mag CD. The older Amplified battery CD is a toatlly different system. Mag CD = good. Amplified CD = not so good. That probably is what Champion was referring to when they said weak spark. First time I've seen them be right.
 

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Re: Plugs 65 HP Johnson, 1972

Will try to post pictures. Hope it works. Also put a p.s. in quotes, new to this too.
Thanks, Leont
 

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Re: Plugs 65 HP Johnson, 1972

Pictures are of my engine, which is the good one I guess. Good thing I didn't bid on the other one. Thanks! Leont
 

jay_merrill

Vice Admiral
Joined
Dec 5, 2007
Messages
5,653
Re: Plugs 65 HP Johnson, 1972

The powerhead on your motor looks like a 1972 Johnson 65hp to me. The silver box with the label on it is your powerpack. The fact that it is the old style metal box, suggests that it may be the original powerpack. If you are having ignition problems, that could be the source of them.

These engines produced about 150 psi of compression when new. I have one that I run quite a bit that still produces numbers in the high 130s to low 140s. Obviously, it would be nice if your numbers were about 20 pounds higher, but they shouldn't keep the motor from performing reasonably well. Its also great that they are so even. Compression values that are more than 10% apart tend to cause motors to run poorly.

Its also worth noting that the accuracy of compression testers varies somewhat. If you have a high quality tester, you are probably getting good numbers. If you have a cheap one, you may not. Also, if you didn't do this already, test compression with the other plugs removed so that the starter can spin the motor easily.
 

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Re: Plugs 65 HP Johnson, 1972

Replaced the stator today. Ran it in a tub. Starts ok and idles. I ran it for 3 to 5 min. at idle in the tub. I have water coming out a small stream at the front of the lower unit and a small amount out the side at the seams. Lot of smoke and can't really be sure if there is water coming out the slots on each side. I can hold my hand on the head with no problem. Hope I am ok now with the water pump also. If this rain lets up some I plan to take it to the lake tomorrow. Will let you know how it goes. Thanks again to all. Hope it works!
Leont
 

jay_merrill

Vice Admiral
Joined
Dec 5, 2007
Messages
5,653
Re: Plugs 65 HP Johnson, 1972

The main water outlets are locate on either side of the gearcase, above the cavitation plate. You may not see water coming out of them for a minute or so, until the t-stat opens.

Let us know how your day on the lake goes.
 

Leont

Seaman Apprentice
Joined
May 1, 2009
Messages
31
Re: Plugs 65 HP Johnson, 1972

Capt. and also an Admiral,
Last time I saw an Admiral it was at a Mass (I'm not Catholic!) Was a Corpsman. Certainly no disrespect, appreciate all the help. That aside, I finally got some good weather and got the boat out. Idles great, starts right up, stayed cool. When I put it into gear it immediately dies. Let it warm up and tried several times but could not get it to go. I also have a lot of what I think is blue smoke and I think it idles a little rough. Starts right up again but noticed I had to choke it each time. I have changed plugs, replaced the stator, have fire to all plugs and checked the compression. Have not as yet put kits in the carbs. Am I missing something? Maybe timing? Will rebuild the carbs, had planned to anyway. Thanks again for all the help. (have a manual but still need advice) Leont
 
Top