1970 johnson 60hp voltage question and more!

[oldboat1]

[ed.] Which control box do you have?

 

[thegipper]

No Title

1970 60hp Johnson model 60ESL70B[FONT=Tahoma, Arial, Roboto Regular, Helvetica Neue, Geneva, Lucida Grande, Verdana, sans-serif], control box looks like this:[/FONT]

 

[F_R]

Safety switch is on a bracket on top of the powerhead, operated by the timer base. It prevents starting at high throttle settings, but does not prevent starting in gear.

 

[oldboat1]

^^learned something! (Thanks, F_R.)

Back to the throttle cable, I think....

 

[thegipper]

Ok I adjusted the throttle cable, the adjustment screw on the motor was cranked in way to far. Now when you pull up the start/run ever, it slightly moves the throttle like normal.

Waiting on my rectifier to come in, should be here on Friday. Hopefully the bad rectifier and weak battery was the cause of all of these issues. Sure hope I didn't mess up the fuel pump when I ran it dry.

 

[thegipper]

I think I should add some additional info:

The "deep cycle" battery that came with the boat is the battery I'm using for the motor. It's what the previous owner used and it is not a gel cell or anything like that. It's four years old based on the tag on it. It does seem to hold a charge fine.

I also have a CMC tilt/trim for the motor. I imagine that thing uses a good amount of juice too. Clearly the rectifier was bad and not charging the battery at all but perhaps a new battery is in order too. I know you generally don't want to use a deep cycle for a starting battery but given my setup, should I get another marine deep cycle or dual purpose? Or should I just get a marine starting battery?

 

[oldboat1]

Think you have a 9 amp stator, which would provide a pretty substantial charge when you get it working.

There is mixed opinion on what batteries to use. I like deep cycles for both starting and house batteries, and have done that for years (inboards and outboards). Maybe size 27, 650 cold cranking amps. Get the big rascals.

Not suggesting you do so, but if you ran an isolator you could pretty comfortably charge both starting and house batteries. Check the draw for that CRC unit, but it is what it is.

I bought an onboard Guest charger last year, and it's working fine for two banks -- and not very expensive. Easy to keep the batteries topped off between outings.

 

[Faztbullet]

Its only 9 amps at WOT....

 

[thegipper]

Ok I installed the new rectifier and checked my voltage before I started the motor (battery fully charged). Voltage dropped to 12.5 once it starting running and slowly climbed up by about .01 volts every second or two. It appears my charging issue has been resolved!

On a side note, it did take awhile to start again =(

Ever since I ran it out of fuel because I forgot to plug the fuel line onto the tank, I've been having the starting issues. The primer bulb was fully collapsed when it ran dry and all I did was hook the line back up and prime the bulb a bunch of times. After quite awhile of try to start it, it eventually did start up and ran fine. It did give me trouble starting again a few more times on the lake. Once it is running, it runs fine and I get the same top speed as before (30mph) and it idles fine.

I checked all three plugs and they look fine and are pretty new (less than two years). Compression tested fine when I bought it last year (only used it a couple times since) 125, 115, 125.

Any thoughts on what it could be? Fuel pump? Power pack/coils (which would be pure coincidence)?

Thanks fellas

PS I went back out an hour later to try starting it again and it fired up right away???

 

[racerone]

If it is the stock , as it left the factory fuel pump it can NOT BE DAMAGED by running it dry.----I would expect to see higher compression numbers on my tester.

 

[thegipper]

I know the compression numbers aren't great but it is a 47 year old motor. Also, the tester I used was one of those crappy push in rubber fitting ones so the numbers are somewhat skeptical.

Someone had mentioned vapor lock, maybe that was the issue. As of right now, it seems to be starting better although before I would always just have to crank it one time and it would fire up. Now it takes maybe three cranks but then it is fine.

 

[oldboat1]

Have a voltmeter, sounds like. After running a while, think you should probably show 13-14 volts. Probably should borrow a screw-in compression tester just to get a baseline on the compression numbers. (With all plugs removed, crank until needle stops rising, note the reading and move to the next cylinder.)

Lot's of folks, myself included, routinely disconnect the fuel line and run the engine until it quits (accurate or not, idea is to empty the carb bowl). There is no damage to fuel pumps doing that -- think that is essentially what you did. Wouldn't hurt to tighten up fuel hose connections, and check hoses for cracks.

 

[thegipper]

Today when I dropped my boat back off at work where I store it, I wen't to start it again to see how she does. Fired up instantly on first crank like before.

Who knows!?!?