Adding Gauges and sensors to old outboards

Franki · Feb 19, 2002

Hi people, I have an old Johnson 100HP, 100ESL72. I also have an older Evinrude 40HP and a Chrysler 6hp (get home motor). I always find myself stressing over the temp, and since none of these old motors have temp gauges or alarms, all I can do, is keep an eye on the water outlets, listen for noise changes or pull the covers and feel the heads.. none of which is exactly relaxing. So I am wondering, has anyone adapted auto gauges to work on an outboard? like a tmp guage or tacho or even a presure guage, (that could be adapted to outboard water pressure)??? I am primarily interested in the Johnson, and I am sure there are alot of people in the same boat, (so to speak). The temp is the most important to me, but a tacho would be nice too, for example, my engine is a V4, so could a 4cyl aftermarket auto tacho be made to work? if so, is the powerpack going to be a problem? Any hints on any useful gauges would be great news to me. rgds Frank

almost retired again · Feb 19, 2002

Re: Adding Gauges and sensors to old outboards

Hi Franki; I have seen temp. senders that bolt under a head bolt. You can hook up a tach. to the yellow grey wire from the rectifier. you probly already have a grey wire in the wireing cable that goes to the control box this is the tach. sending wire. lots of luck

petryshyn · Feb 19, 2002

Re: Adding Gauges and sensors to old outboards

Hello Franki An automotive temp gauge will work. An automotive tach can be made to work, but its not worth the hassle. Check here for cheap gauges and tach's. If you mount a automotive temp gauge, mount the sender like this or like this Good luck!

Lark40 · Feb 19, 2002

Re: Adding Gauges and sensors to old outboards

As for the tachometer, I am planning to buy a Tiny-Tach for my 1960 Evinrude Lark 40 with its magneto ignition . They also have models for your 4 cyl engine. Check out: www.tinytach.com I've been thinking about the temp gauge Schematic suggested. If I find I'm really paranoid about overheating this year(like last year), then that's the only good solution.

Franki · Feb 19, 2002

Re: Adding Gauges and sensors to old outboards

Wow, a 1960 Lark Evinrude 40hp, you just described my old motor, has a cover that looks like its off a 58 chev, and it has a hatch on the front of the cover.. Is that the same one? Isn't there already connections for a tack in the wiring harness of that unit? My Johnson, the one I want to add guages to has everything built into the remote control, including the key. is the wire I need really inside that thing? I have heard of the temp guages that fit under a head bolt, how accurate is a readin from there? I suppose that would still enable you go get a overheating reading as the outside of the head shouldn't get over 80degrees C should it? Thanks for the tips guys.. rgds Frank

Lark40 · Feb 20, 2002

Re: Adding Gauges and sensors to old outboards

More like a 1957 Chevy BelAir with it's sideways "V" brightwork. There is no provision for a tach in the wiring harness. There is an ammeter wire for a generator, but I don't even have one. I keep the starter battery charged at home and don't need to make electricity while running (just like a lawnmower). I guess that the water temp sensor has to be in the water within the water jacket. Don't think that gauging heat from a head bolt would work.

Franki · Feb 20, 2002

Re: Adding Gauges and sensors to old outboards

Hey Mr Lark.. Isn't your lark a Selectric? it has an electric gearbox, two electric clutches on the probshaft, when one is engaged, you go forward, when the other is engaged you go backwards, and if both are engaged, you spit gears out the side of your leg.. (and if both are disengaged you are in neutral.) Mine seems to flaten the battery in about 5 or 6 hours running in gear. (my regulator is fried) these engines have a nasty downside. if your battery gets to low to power the clutches, you get left with an engine that runs but doesn't go anywhere. (been there twice.) Some Temp guages have a copper lead that you are supposed to slide up a radiator hose in a car.. you can do the same thing with the outboard.. but if you use thermal paste and attache it to the cilender head, you'd get much the same effect, I plan on trying it today. rgds Frank PS. I am sure I can rig up a temp guage, but I have no idea how to be sure I can get the right tacho to work on this thing.

Lark40 · Feb 20, 2002

Re: Adding Gauges and sensors to old outboards

The electric shift 40 hp was not an Evinrude option for 1960. I think that it first became available the next year. In any event, Evinrude continued making both electric and manual shift 40 hp engines into the 1970's. Let us know how the temp gauge works.

petryshyn · Feb 20, 2002

Re: Adding Gauges and sensors to old outboards

Gents, with regards to mounting the temp. sender.....did you even read this?

Franki · Feb 20, 2002

Re: Adding Gauges and sensors to old outboards

Yes sir Mr Schematic.. I did indeed read all the links you provided, and I even saved the PDF files to my desktop.. but it depends on several things. 1. What sort of guage I have available to me here in Australia. 2. What I can presently afford. 3. What I can get without lengthy shipping times. I need only a simple system, if I know the head is not above 50-70 degress.. then I am happy.. and any method that works is good. I went looking for the blank hole on my powerhead that pdf said I'd have and couldnt' find it.. at least not the one they describe.. I'll work something out, but I certainly do appreciate the infomation. Thankyou for your suggestions and stuff. now I have to work out what i can do given my specific circumstances. kindest regards Frank Hauptle

petryshyn · Feb 20, 2002

Re: Adding Gauges and sensors to old outboards

The "Z" style of bracket (which you can make yourself) will mount any style sender to any style head. I didn't mean to necessarily purchase the teleflex, just to use their mounting ideas. Good luck!

Franki · Feb 20, 2002

Re: Adding Gauges and sensors to old outboards

Hello again.... I guess I'll know better what I am in for when I see what guages are available for me.(I am heading over to a auto parts joint now.) Lark40 mentioned Tinytach recently and said their were models for V4's, but I went to their site and pretty much everything I could see was for single, double and triple cylinders.. I didn't see anything for 4 cylinder 2 strokes.. any suggestions as to which one would work? rgds frank

petryshyn · Feb 20, 2002

Re: Adding Gauges and sensors to old outboards

The tiny tach can't tell the difference between a 1,2,3,4 cyl. 2-stroke,as long as there's no waste spark. A 1 cyl. will work just fine. (check your e-mail)

Franki · Feb 20, 2002

Re: Adding Gauges and sensors to old outboards

Thanks for that diagram,, its pretty similiar alright.. though there is no reference to the coil or powerpack in that diagram. (does the 65 have the powerpack?) I think the wiring is exactly the same. Thanks for the pdf of the Z bracket, I'll be following that one to the letter once I get the leg back together and on the outboat. One last question, on cyl no3. there is a wire running out of the head.. its brown and leads into the main loom of the wiring harness. I thought this might be an exectronic decompression valve (for easier starting..) but after thinking about it, I decided it probably wasn't.. do you know what it is? rgds Frank

petryshyn · Feb 21, 2002

Re: Adding Gauges and sensors to old outboards

don't have a diagram in front of me, but its probably a temp warning sensor for a horn...the diagram I sent you is just for the shift mechanism, not the whole engine. good luck!

Franki · Feb 21, 2002

Re: Adding Gauges and sensors to old outboards

Thats really very strange, there doesn't apeaar to be a horn or any other method of notifing of high temp.. Guess I might have to strip off some tape and find out where it actually goes them. I endedd up getting a VDO electric Temp guage, (VDO were the only electric one I could get.) it comes with a sensor that looks alot like the one in the pdf link you posted. I am looking into different methods of mounting it now, one of which is the z bracket. the other is a _|--|_ sort of shape, bolted to the head at each end. (two bolts. This would ensure that the two faces, (the head and the sensor) are held very tight and perfectly flat.. with a bit of thermal grease, it should work very well. Thanks again for all your tips and stuff. rgds Frank

almost retired again · Feb 21, 2002

Re: Adding Gauges and sensors to old outboards

Hello Franki; I had onr of those old 40's, it's been a long time ago if I remember correctly that tan wire went to the dash to an overheat warning light that had a positive supplied by the key switch when the sender got hot enough it went to ground thus causing the light to come on. This is comming back to me from 20+ years ago so I could be wrong.

petryshyn · Feb 21, 2002

Re: Adding Gauges and sensors to old outboards

Franki I believe it was a buzzer hooked to the temp switch. Atleast thats what they did in 73. As almost says, a light would work as well. The guy in the auto store is misleading you. It is not as simple as connecting as connecting a auto tach to the coil. You don't have a conventional ignition. The problem is, its going to take some experimenting to get an auto tach to work. Do you want to risk tach or pack damage. If you do, than I'll help hook it up. Much simpler to buy a used teleflex tach. Thats what I'd advise. Good luck!

Franki · Feb 21, 2002

Re: Adding Gauges and sensors to old outboards

Hi guys, Firstly, Mr schmatic, you are right, I have no desire to risk my new powerpack, it was much more expensive then a tacho would be useful

As for the brown wire, I checked both outboards (100ESL72 100HP 72 Johnson, and a Lark40, Evinrude 62 40HP.) Both have the tan wire, its on the bottom head of the 2 cyl 40HP, and its on cyl 3 head on the 100HP Johnson. problem is I can find no buzzer or horn or warning light on any of them, the 100HP is the worst, it has a one piece controller, everything is in that, including the key. and there does not seem to be a buzzer in there.. On another note, is it safe to open the remote controller, link into the ignition wire, run it through a relay so that I can get ignition power to any guages that I mount on the boats dash? (safe to the powerpack I mean.) rgds Frank

petryshyn · Feb 22, 2002

Re: Adding Gauges and sensors to old outboards

Yes you can link to the ignition switch, and the way you describe is great using a relay.(put a diode across the relay coil to prevent any regulator damage if so equipt)But...if you're only installing gauges, a relay is not needed, cause they draw so little current. Just wire them direct.The 12v side of the ignition switch is not related to the power pack. The buzzer may have been a stand alone device as the horn is. If you don't have one, piezo horns are really cheap and draw low current. I can help with the wiring if needed.....

Adding Gauges and sensors to old outboards

Lieutenant Junior Grade

Chief Petty Officer

Commander

Senior Chief Petty Officer

Lieutenant Junior Grade

Senior Chief Petty Officer

Lieutenant Junior Grade

Senior Chief Petty Officer

Commander

Lieutenant Junior Grade

Commander

Lieutenant Junior Grade

Commander

Lieutenant Junior Grade

Commander

Lieutenant Junior Grade

Chief Petty Officer

Commander

Lieutenant Junior Grade

Commander