1974 Evinrude Charging system mystery

[ckraker]

Thanks in advance for any help.
I have a 1974 135 hp Evinrude Outboard
The Engine starts perfect and runs out of the water perfectly. When I get in a lake it lacks power and won't get as high rpms as it should. Everyone suggests that its a carb or prop problem. I know I have the correct prop and I know the Carbs are good. The problem I believe is in the charging system. I know it sounds odd, but somthing is amiss. My battery at rest is at about 12.6 volts and with the engine running and revved up it only get to 12.8. Some more info:
The Tachometer doesn't work
The rectifier diodes are all good.
The stator doesn't have any shorts or opens. The Brown to brown/yellow wire resistance is about 880 ohms (specs say it should be 400) not sure if that is okay.
The yellow wires are putting out just over 13 volts and the Red from the rectifier is the same.
The odd thing about this engine is that it is the only one of 4 models made in 1974 that has a rectifier and a separate voltage regulator the guys at my local shop had never even seen one before.
If anyone has any tips on how to test a voltage regulator, or know what else I should be checking on this motor please let me know.

 

[Rscardina]

Re: 1974 Evinrude Charging system mystery

Thanks in advance for any help.
I have a 1974 135 hp Evinrude Outboard
The Engine starts perfect and runs out of the water perfectly. When I get in a lake it lacks power and won't get as high rpms as it should. Everyone suggests that its a carb or prop problem. I know I have the correct prop and I know the Carbs are good. The problem I believe is in the charging system. I know it sounds odd, but somthing is amiss. My battery at rest is at about 12.6 volts and with the engine running and revved up it only get to 12.8. Some more info:
The Tachometer doesn't work
The rectifier diodes are all good.
The stator doesn't have any shorts or opens. The Brown to brown/yellow wire resistance is about 880 ohms (specs say it should be 400) not sure if that is okay.
The yellow wires are putting out just over 13 volts and the Red from the rectifier is the same.
The odd thing about this engine is that it is the only one of 4 models made in 1974 that has a rectifier and a separate voltage regulator the guys at my local shop had never even seen one before.
If anyone has any tips on how to test a voltage regulator, or know what else I should be checking on this motor please let me know.

I don't know your engine per say but the tach issue is usually tied to the rectifier/regulator circuit. I'm not sure if you have these fused or not but it is certainly worth checking.
The resistance on the stator, although, out of spec, may be connection issues, dirt contactc points etc.. The fact that she does run tells me that its doing something, right or wrong its allowing power generation to then induce your sparking. so my gut says you are ok there but may need to recheck connections.
i would verify tach issues first just to be sure your tach is in fact bad, which can happen or if its good which leads you back toward the regultor/rectifier.

clean your battery terminal good and tighten them down. with a meter across the battery..have someone rev the engine and see if power picks up if it does then the charging portion is ok.
its my understanding the the timer base has something to do with the tach as well (dont know if you have one)..but another place to look.
the power issue at top end points to carbs..high speed jets.. i know you say they are good but have you, for sanity reasons, checked and cleaned them with a fine tooth comb?..

 

[ckraker]

Re: 1974 Evinrude Charging system mystery

I actually paid someone to clean the carbs, so I cannot say for sure that they are spotless. I just assumed he did a good job considering it cost nearly 400 dollars. I'll pull them and Check again tonight.
about the charging--- The battery at rest is 12.6 and when the engine running and revved it goes up, but only to 12.8. Is that a sufficient charge?

About the timer base having something to do with the tach..... Is there a way I can test that? I do have a DMM with a DVA.

 

[glengold]

Re: 1974 Evinrude Charging system mystery

I'm having a similar problem with my '77 55hp 'rude. Mine is at 12.7~8 at rest then drops to 12.4~5 WOT. Shouldn't the motor continue to run if disconnect the battery? I have the large wires going to the batt posts, then several smaller one's bolted on the batt screws. I didn't want to fry anything. My mechanic told me to replace the voltage regulator bc it's very rare for just the charging side of a stator to go out, he says if its running the stator has got to be good. I thought it was possible for the motor to run completely off the battery. Also I have not checked spark but think that may be the power issues, if the motor is just running off the batt, its not getting enough for a good spark.

 

[Rscardina]

Re: 1974 Evinrude Charging system mystery

I'm not sure how to check your timer base. I have my engine manual that tells me how to test mine but I cant say for sure if your would be different.

I would ask someone here about or look up some threads using the keyword timer base or something..

as far as the carbs go.. dont pull them off..just unscrew the bowl drain plug..the jet is behind it.. so take some carb spary and shoot some in and see if it comes out of the little straw in the center of the carb..if it does then you should be ok there too.. you can take a wire and push it into the jet to be sure its clear as well.

If you dont have your manual...I suggest getting one if you plan to do work yourself. its worth every penny and will pay for itself on your first repair..

take a look here fore exploded views of your engine

http://shop2.evinrude.com/Index.aspx?s1=5852da2bf93b7d5cf488739e8d730a2b&catalog_id=0&siteid=1

 

[glengold]

Re: 1974 Evinrude Charging system mystery

My old 50 hp would be at 15 volts WOT, that thing ran 10 mph faster than this 55. I hope this kills two birds w/ one stone: dying batt and low power. I'll keep you posted

 

[Rscardina]

Re: 1974 Evinrude Charging system mystery

I'm having a similar problem with my '77 55hp 'rude. Mine is at 12.7~8 at rest then drops to 12.4~5 WOT. Shouldn't the motor continue to run if disconnect the battery? I have the large wires going to the batt posts, then several smaller one's bolted on the batt screws. I didn't want to fry anything. My mechanic told me to replace the voltage regulator bc it's very rare for just the charging side of a stator to go out, he says if its running the stator has got to be good. I thought it was possible for the motor to run completely off the battery. Also I have not checked spark but think that may be the power issues, if the motor is just running off the batt, its not getting enough for a good spark.

dont disonnect the battrey while running the engine..you will blow the rectifier/regullator..

once the engine is on..it should make its own power to stay running. thats what the magnets do..they spin over the stator and create voltage...this is what keeps the engine firing..not your batteries. they are only there to start and run accessories..

I would alsways start with taking wires off the batteries and cleaning everything with sand paper ..I mean everything... put it all back as you found it and then check voltage again.. more than not..you may have a bad battery that doesnt take a charge...

 

[ckraker]

Re: 1974 Evinrude Charging system mystery

I have an old Generic Manual that wants me to test everything with a Neon Tester (whatever that is). What brand Manual do you suggest I buy? Also-- the battery is brand new-- just bought it yesterday.

 

[Rscardina]

Re: 1974 Evinrude Charging system mystery

I have an old Generic Manual that wants me to test everything with a Neon Tester (whatever that is). What brand Manual do you suggest I buy? Also-- the battery is brand new-- just bought it yesterday.

neon?? what?.. I have heard of induction timin lights..but neon?.. I gues I'm not that old..

Manual should be an OMC or shop manual if you can get one. The clymer or seloc, ones are ok but not as detailed and certainly not step by step..

did you check out the link i sent.. Evinrude site that has exploded views?..its pretty good to see what makes up each section..

if your batt is new then double check connections.. if she reves and doesnt increase voltage then charging system is definitely having issues. and usually regulator.rectifier is the culprit. one more thing.. disconect the tach..and see if that make any difference.. a bad tach could cause regulator/rectifier to blow..you dont want to replace only to replace again..

 

[ckraker]

Re: 1974 Evinrude Charging system mystery

. if she reves and doesnt increase voltage then charging system is definitely having issues.

It goes up about .3 volts Is that considered a charge?

 

[F_R]

Re: 1974 Evinrude Charging system mystery

neon?? what?.. I have heard of induction timin lights..but neon?.. I gues I'm not that old..

Manual should be an OMC or shop manual if you can get one. The clymer or seloc, ones are ok but not as detailed and certainly not step by step..

did you check out the link i sent.. Evinrude site that has exploded views?..its pretty good to see what makes up each section..

if your batt is new then double check connections.. if she reves and doesnt increase voltage then charging system is definitely having issues. and usually regulator.rectifier is the culprit. one more thing.. disconect the tach..and see if that make any difference.. a bad tach could cause regulator/rectifier to blow..you dont want to replace only to replace again..

Everybody likes to promote the factory service manual---only. The fact of the matter is, the factory manual was written in 1974 (in this case), and it specifies the use of a Stevens Neon Tester-----an obsolete method. This is 2010 and a DVA meter is the way to go. It won't be in the 1974 book.

 

[Rscardina]

Re: 1974 Evinrude Charging system mystery

It goes up about .3 volts Is that considered a charge?

.3 volts is not a change in my opinion. what i have read here is something like..12.5 volts say to start and then 13 ..13.5..etc or so to 14 as you start reving up more. you meter should see the increse climing as the revs go up..

Also, look at the new posts in the Johnson section..someone posted something similar and Joe reeves responded with some troubleshooting tips regarding tachs and charging system.. good info


to F-R, I learned that from here...it seems the original book is alwys the best as it give more info and in more detail for your engine. Not saying other dont but the neon comment was the first I had ever heard. I assume before timing light..there was neon?.. my book is an 86 for my engine..no mention at all about neon.

 

[Rick-va3rzs]

Re: 1974 Evinrude Charging system mystery

about the charging--- The battery at rest is 12.6 and when the engine running and revved it goes up, but only to 12.8. Is that a sufficient charge?

you should have 13.2 volts to charge your battery

the charge should be the same at idle as at 1/2 speed it should be a stable voltage as not to cook the battery

 

[glengold]

Re: 1974 Evinrude Charging system mystery

dont disonnect the battrey while running the engine..you will blow the rectifier/regullator..

once the engine is on..it should make its own power to stay running. thats what the magnets do..they spin over the stator and create voltage...this is what keeps the engine firing..not your batteries. they are only there to start and run accessories..

I would alsways start with taking wires off the batteries and cleaning everything with sand paper ..I mean everything... put it all back as you found it and then check voltage again.. more than not..you may have a bad battery that doesnt take a charge...

Thats what I was worried about. Didn't want to fry anything.

I should have the new voltage regulator in tomm. I will go through all the wiring. The old motor would pump close to 16 volts into that batt. I'm worried that along w/this motor constantly draining it that the batt may be on its way out. Shouldn't i still get a higher voltage reading when the motor is running WOT, even with a batt on its way out?

 

[glengold]

Re: 1974 Evinrude Charging system mystery

removed the voltage reg and found the red wire was completely corroded! will test this weekend w/new voltage regulator and report any changes in performance. I hope i get another 10 mph out of it!!!

 

[Rscardina]

Re: 1974 Evinrude Charging system mystery

attaboy! thats the worst offender of voltage issues. corroded or non-tight connections drain voltage and your volt meter may not pick it up..

if one is corroded then you may as well check more..clean up as much as you can..so worth the time ...

 

[Rscardina]

Re: 1974 Evinrude Charging system mystery

Shouldn't i still get a higher voltage reading when the motor is running WOT, even with a batt on its way out?

No..if your battery is going bad and not able to accept the charge the votage regulator adjusts for that. so it compensates giving less..

 

[F_R]

Re: 1974 Evinrude Charging system mystery

.3 volts is not a change in my opinion. what i have read here is something like..12.5 volts say to start and then 13 ..13.5..etc or so to 14 as you start reving up more. you meter should see the increse climing as the revs go up..

Also, look at the new posts in the Johnson section..someone posted something similar and Joe reeves responded with some troubleshooting tips regarding tachs and charging system.. good info


to F-R, I learned that from here...it seems the original book is alwys the best as it give more info and in more detail for your engine. Not saying other dont but the neon comment was the first I had ever heard. I assume before timing light..there was neon?.. my book is an 86 for my engine..no mention at all about neon.

Not related to a strobe timing light. Stevens S-80 neon tester and/or Merc-O-Tronic M-80 neon tester. Used to detect high voltage pulses such as pulse pack output. It told you if there was a pusle but didn't say how strong a pulse. A DVA measures it.

Stevens no longer makes it, offering instead a DVA meter. Not sure about Merc-o-Tronic.

Here's a picture of the M-80...http://cgi.ebay.com/ebaymotors/MERC...STER-/400135984051?pt=Motors_Automotive_Tools

 

[Rick-va3rzs]

Re: 1974 Evinrude Charging system mystery

No..if your battery is going bad and not able to accept the charge the votage regulator adjusts for that. so it compensates giving less..

if you battery is going bad it will soak up as much amperage as it can and put a load on your system .. but will not store it .. most times its not the whole battery just a cell or 2 that has gone bad ..