Tachometer on '69 Johnson 55hp outboard

[bobandpeni]

Hi, I'm new to this website but I thought I'd give this a try. I'm also new to boating but not to working on old machines, I keep a '67 Triumph TR4 and an old Jag on the road. The Jag website has been very helpful over the years and I hope this may be the same. Thanks in advance to all who reply.<br /><br />I've got a '69 Johnson 55hp outboard, Model Number:55ESL69A and Serial Number:3013167. I would like to install a tachometer on to my boat but I don't know what to buy and therefore how to install it. The service man at my marina said not to waste my time since no one makes a tach for this motor anyway. I find that hard to believe, either there is one made or someone has an old one laying around, I'm hoping someone here might have my answer.<br /><br />Since I'm new to the motor (which was pickled for nearly 20 years) I had the techs at the marina go over the motor. They rebuilt the carbs, sync'd the ignition and throttle, replaced the plugs and basically made sure everything was in running order. They did tell me that when my motor blows its ORIGINAL ignition box to throw the motor away. They tell me a replacement is $450! Maybe someone here can either suggest how to prevent my burning up my original or suggest where to buy replacements a little more reasonably. Advice is welcome.<br /><br />Well that should be enough to keep us busy for now.<br /><br />Thanks again,

 

[OBJ]

Re: Tachometer on '69 Johnson 55hp outboard

Hi Bob. Welcome aboard the forums!<br /><br />Yes, you can get a tach for you engine. In fact, if you have the original wire harness that runs to the dash, the should be a gray and black wire capped off. These would be the tach signal wire and ground wire. All you would have to do is supply 12V's from the ignition system. Check iboats Mega Mall for tachs. I'm sure you can find one there.<br /><br />And the ignition system amplifier is $305 not $450. Not much consolation but a little. Might get it a little cheaper from iboats.....have to check that out and see if they carry them... <br /><br />If you have any other questions, don't hesitate to post......thanks.<br /><br />EDIT: Just did a search through iboats mega mall....they do have your amplifier. Their part number is 18-5747. Cost...$216.47. Good price. See the link below...<br /><br /> http://www.iboats.com/mall/index.cgi?prod_id=42206&current_category=power pack&*******=749086654

 

[WillyBWright]

Re: Tachometer on '69 Johnson 55hp outboard

Your current amplifier may be just fine if that motor has been sitting so long. The leading cause of amplifier failures relates to the power supplied to it. Loose or corroded battery connections will fry those real quick. On most motors of that type and that old, that has probably happened already. But since yours has been sitting so long, that may not have happened. It is super critical that the battery connections be clean and tight at all times. You should also have a very good battery in very good condition. Throw the wingnuts away and invest in some stainless steel locknuts so you're never tempted to let finger-tight be good enough. The price the marina quoted is probably pretty close if it includes labor and a new coil. If you do end-up getting a new amp, then it'll advise you to also get a new coil. iboats price on the amp is about $100 below the going rate.<br /><br />Make sure you have fresh gearlube and have the water pump rebuilt, although I expect your mechanics already have those bases covered. Don't forget to add oil to the gas. There are endless debates as to what you should use, but anything you find now is much better than what was available in 1969, so don't sweat it. Personally I like the Johnnyrude stuff. It's more expensive, but smokes less than the cheap stuff.<br /><br />Regarding the tach, I don't know. OBJ is probably on the right track. If all else fails, there are tachs out there that will work on any motor using a basic inductive pick-up which is usually nothing more than a wire wrapped around a sparkplug wire. Those will work on anything but a diesel.<br /><br />Good luck and welcome to iboats.

 

[bobandpeni]

Re: Tachometer on '69 Johnson 55hp outboard

WOW! I'm excited that I got some responses to my questions. This forum will be a good resource for me and I appreciate the input. Sadly, due to my lack of experience, I probably won't be contributing too much for now.<br /><br />Willy, the marina guys told me that if it wasn't broke don't fix it. The water pump apparently put out the quantity of water that it should so they left it alone. I bought a service manual from Seloc (It's lousy in my opinion and I think I'll be buying the original Johnson manual if I can find one) and it recommended changing the water pump yearly, then again they recommended taking the prop off after every use! I'm not quite sure what to do concerning the water pump. I wouldn't be beyond trying to change it myself if I had the Johnson service manual and perhaps a parts manual for the breakdowns, unless someone here with experience says that this is one of those jobs best left to the pro's.<br /><br />I do have the original wire harness so I'll be looking for those tach wires. Not to sound too ignorant, but since I haven't seen one of these tachs would the supplied 12v from the ignition system be applied to the tach or to the ignition system somehow.<br /><br />Thanks guys!!!

 

[R.Johnson]

Re: Tachometer on '69 Johnson 55hp outboard

The tach senses off the alternator, that's where the gray wire is coming from. As I recall, the 12 volt wire just powers the back light on the tach. Any OMC tach will work with this engine, just set to the correct pulse.

 

[juice71]

Re: Tachometer on '69 Johnson 55hp outboard

could u guys give me more detail on seting up the tach? I have same motor and was unaware that I could do this.

 

[bobandpeni]

Re: Tachometer on '69 Johnson 55hp outboard

I've found two used OMC tachometers but I'm not sure if they are compatible with my motor. One is for an OMC SEA DRIVE or any other engine with 5 or 6 pulse alternator part # 174630, the other is off of a 1985 V-4 90HP Johnson. Will either of these work for a '69 3 cylinder Johnson 55? <br /><br />If not, what questions should I be asking to find one that will work? I also have an old Sun auto tach that connects to the distributor. I imagine that the Sun Tach counts pulses at the distributer, but being that I've never connected a tachometer up (other than the idiot proof cable type on my TR4) I'm not quite sure what the tachs are counting. I would think that if the Sun Tach was counting how many times the distributor sent voltage to a plug there would be some type of way to compensate for the number of cylinders since that would seem to me to make a difference. It would be ideal if my tach was for a 6 cylinder 4 stroke since there would be the same number of plug firings per revolution as on a 3 cylinder 2 stroke.<br /><br />Can anyone help?<br /><br />Thanks again for everyones input.

 

[Paul Moir]

Re: Tachometer on '69 Johnson 55hp outboard

Bob, <br />The charging system on an outboard is completely unlike that on a car, but pretty much just like one on a motorcycle. Basically, it's a number of coils up underneath the flywheel, together called a 'stator', which are passed over by several permanent magnets mounted to the flywheel. Each time a magnet passes over a coil, an electrical pulse is created which goes on to charge the battery (via the rectifier and regulator if present). It's these pulses that the tachometer counts rather than pulses from the ignition system.<br /><br />Your 55hp engine produces 6 pulses per revolution, as it has a 12 pole stator. Confusing things, later 2 cylinder 55hp engines produced only 5 pulses per revolution (10 pole stator). Clearly, the Sea Drive on will work. The V-4 also produces 6 pulses per rotation, so it will work too. <br /><br />Your marina may have been thinking of simiair vintage 2 cylinder Johnson/Evinrude engines, for which dash tachometers are fairly difficult to find.<br /><br />As for a factory repair manual, reprints can be ordered from the following places:<br />TheOutboardWizard<br />Mastertech<br />Marine Engine<br />Ken Cook <br />Sometimes they pop up used on ebay for considerably less. But unfortunately I don't see any at the moment.

 

[bobandpeni]

Re: Tachometer on '69 Johnson 55hp outboard

Paul,<br /><br />Thanks for the lesson. I'm starting from scratch but quick to learn. It's great to have such helpful people willing to share their experience with a beginner like myself.<br /><br />I've been searching e-bay for some time for a reasonable set of manuals with not much luck. I know of one place the will sell the service manual, parts manual and operating manual for about $80 which will be plan B if E-bay doesn't have something for less.<br /><br />Thanks for the links!!!!!!!!!

 

[WillyBWright]

Re: Tachometer on '69 Johnson 55hp outboard

The water pump must be rebuilt no matter what. That rubber impeller in there is over 20 years old. It's made of rubber and rubber hardens over time. Continued use of that impeller is extremely unwise. It needs to be replaced or you could have a failure that would cook the powerhead. I'm astonished your mechanics discouraged a water pump rebuild. I'd bet a week's salary that 99% of dealers would strongly recommend it. If one vane breaks off, the whole pump goes out very quickly and your powerhead gets no more cooling water. Rebuild it. Trust Me!

 

[bobandpeni]

Re: Tachometer on '69 Johnson 55hp outboard

Willy,<br />Thanks for the advice. I was surprised too by their advice to NOT change the pump, but then they have reminded me that they have 54 years in the business! <br /><br />I guess that the next question is how hard is it for an amateur like myself to change that waterpump? All of my tinkering experience is on cars. I've changed heads, transmissions and the like, but what things do I need to pay attention to when I disassemble and reassemble the lower end of this motor? Are there any other things that someone with experience would change while the lower unit is opened up? I'll buy the Johnson service manual before attempting this, will it do a fair job of leading me through the steps required.<br /><br />Thanks for your advice.

 

[WillyBWright]

Re: Tachometer on '69 Johnson 55hp outboard

Getting it apart is easy enough. The hard part is getting it back on. The shift wires have to be routed carefully and the water pipe guide tubes like to fall out of place. Easiest way to get the wire routing right is to attach a string to the wires before pulling them out. That way yau can just reattach and pull the wires back with the string. As far as the guide tubes, glue them to the water pump. The manual will be very helpful with this.

 

[rodbolt]

Re: Tachometer on '69 Johnson 55hp outboard

helo<br /> yep the hard part is getting the harness out of the powerhead adaptor without breaking it. the last harness I bought was 120. I have never found a way to splice the wires satasfactorily. it always fails after the splice.