Johnson 200 charging system

[prozac]

I have a 1994 Johnson 200 Oceanrunner. One and 1/2 years ago the charging system and tachometer would sometimes stop working but would then start working again. A mechanic replaced the regulator/rectifier and it cured the problem until now. When the tach quits the charging also stops but they usually start working again in a little while. RPM seems to have no effect. Should I buy another regulator rectifier or do I have a problem elswhere? Is there something that is causing the rectifier regulator to fail or is my problem really elsewhere?

 

[Dhadley]

Re: Johnson 200 charging system

Your regulator goes bad because of heat. Let's assume your water pump is working fine and you have plenty of pressure. <br /><br />The block tends to get an air pocket in it at the top and not fill up with water. The regulator will then heat up and eventually go bad. The wiring may catch on fire. <br /><br />To eliminate the air pocket simply vent the top of the block. Drill into the water jacket above number one cylinder on the block (not the head) and install a fitting number 331894. You can vent it thru the pan so you will have a second overboard indicator. The fitting requires a small hose and you can restrict it further if you like. All we want to do is vent the air so it doesn't take much. <br /><br />Good luck!

 

[prozac]

Re: Johnson 200 charging system

DHADLEY,<br />Thanks for the info. What you said makes a lot of sense. Is that fitting number an OMC part?

 

[Dhadley]

Re: Johnson 200 charging system

Yes it is. It's a standard 90 degree plastic fitting.<br /><br />Good luck!

 

[goldberg]

Re: Johnson 200 charging system

I have a 1994 Johnson Oceanrunner 200 HP with a similar problem to prozac's initial post. Everything was fine, then tachometer starts to work intermittently, now tach doesn't work at all. Other posts point to the regulator/rectifier or associated equipment as being a prime candidate for the source of the problem.<br /><br />This is the first problem I've had with the motor, so I don't yet own a repair manual. One is on the way, however.<br /><br />1. I started the engine today and at idle saw no increase in voltage anywhere (battery terminals, panel, on the motor). Sounds like something in the charging circuit is bad. Any troubleshooting tips on the regulator, rectifier, etc.?<br /><br />It was not obvious to me where the rectifier is even located.<br /><br />Does this motor have a separate rectifier, or does a whole module have to be replaced?<br /><br />2. Any troubleshooting tips on the tachometer? What kind of signal does the tach take for an input? Something measurable by an oscilloscope or multimeter?<br /><br />3. The previous owner did not have any problems with regulators/rectifiers overheating, etc. Also the water pressure is fine. Should I still install the jacket air bleed fix as described above?<br /><br />Thanks for the help<br /><br />Adam

 

[Dhadley]

Re: Johnson 200 charging system

The tach "feed" comes from the reg/rec. It's located at the top of the block under the power pack. You have just described the classic symptoms of a bad reg/rec. <br /><br />Good luck!

 

[goldberg]

Re: Johnson 200 charging system

One more thing - I have some read posts concerning blowing a rec/reg if you are using two batteries at once. I do have two batteries and normally use both. Charging a battery only takes several amps (I did check today - they are both at essentially full charge - they drew about 3 - 4 amps on the battery charger). How can a several amp drain on a 30+ amp charging system be problematic?<br /><br />Is it "normal" to expect to blow a rec/reg when using both batteries?<br /><br />Any troubleshooting possible for a bad rec/reg?<br /><br />Thanks<br /><br />Adam

 

[petryshyn]

Re: Johnson 200 charging system

The bad thing about having two batteries hooked in parallel (without an isolator) is that one may have a higher open-circuit voltage than the other (because of age, type etc.) This would cause one battery to drain itself while trying to bring the other up to its same level. In short, if your batteries are missmatched due to age, size or type, they MAY go down in charge when left sitting. Then when you start the engine, the charging system works for a longer period of time trying to bring them both up in charge. This even compounds if the engine is idled for a period of time once started, because the cooling to the rec/reg assmy. is lessened.(a weak cooling system can also contribute) For trouble shooting, just put a voltmeter accross the battery while the engine is running and see what the regulated voltage is. You should have the engine up to atleast 2000 rpm when you do this test. If the battery is up in charge as you say, you should measure atleast 13.8 volts while doing this test. If both batteries are hooked up during this test, and they are low in charge, it may take awhile for the voltage to reach this level. Regulated voltage is very subjective to the amount of current the electrical system is demanding. Regulated voltage should be checked with minimal electrical load. Checking the current output would require an ammeter (preferably a clamp-on) which would allow you to see if this charging system can produce its 30 amps. Turn on all accessories (engine rpm up to atleast 2000 rpm) and measure the current output right from the rec/reg unit. As in most charging systems, the hardest thing on them is high current requirements (low batteries or all accessories on) at low speeds.(poor cooling)

 

[Bluefish]

Re: Johnson 200 charging system

You might want to ck that you have a good ground, (When the tach quits the charging also stops but they usually start working again in a little while). When tach starts danceing or guits and comes back most times its a grounding problem.The tach runs of rec/reg and charging will stop.<br />Good Luck

 

[goldberg]

Re: Johnson 200 charging system

Thanks for the advice given above. I took it to the shop and the guy took off my old rec/reg and it was crispy fried. The mechanic did say that my engine had a poppet valve which would release steam/air if it was trapped in the top of the cooling jacket. I am interested to find it to make sure that this is the case.<br /><br />The mechanic did recommend not running both batteries at once.<br /><br />I guess the difference between a battery charger and the motor's charging system is that a battery charger puts out a voltage just above the batteries voltage (say 12.8V) and therefore a reasonably small current (several amps); whereas the motor's charging system will put out 14.5V for example and therefore more current. That's my hypothesis at least.

 

[petryshyn]

Re: Johnson 200 charging system

It requires atleast 1 volt above the battery voltage to force electron flow through a battery in reverse direction. eq. a 12.3v battery must have a minimum of 13.3 volts applied to it to start the charge process. This applies to chargers or charging systems. The ideal charging voltage ranges from 13.8v - 15v . (dependant on the battery's ambient temperature and the "water to acid ratio" at the time of manufacturing) The current flow at this voltage will be dependant on the battery's condition. In a nut shell...if you want to charge two batteries at the same time with your engines charging system, but are afraid to overwork the system, simply put a bulb (1156) between the positive posts. This will limit the current to the accessory battery, and bring it up in charge over time. . .