90 HP Johnson Questions

[kyudizky]

Preface- excuse my outboard ignorance, im leaning, and have ordered the $90 OEM manual, as so many suggested.

Q #1
I was told, when I purchased my '91 Stratos F and S that it was believed to be factory rigged. Well after looking at the model year finder on shop.evinrude.com, apparently my J90MLCRD motor is an '84. The M also suggest evidently that is a manual trim motor, but is actually has power t/t. Could power t/t have been added. I'm confused?

Q #2
This all came about when my motor wouldn't turn over. After troubleshooting, with help from you guys, my battery is not being charged while the motors running. It reads just under 12V both static and while running (according to a multi-meter). Cleaned all corrosion of battery ad connections, and nothing different. Being a car guy, i think I need a new alternator. After researching it seams that recharging is done by a voltage regulator/rectifier on an outboard. Is this true, it this the part I need to replace??? Can this be a do it yourself-er like an alternator is on a car???

When the battery has juice, it cranks right up and runs great.


Thanks for your help and for learning us newbies to outboards!

 

[Daviet]

Re: 90 HP Johnson Questions

Maybe by factory rigged they ment just cables and controls? Trim and tilt could have been added at a later date. The stator produces charging amps, controlled by the rectifier. When you get your manual it will ansewer a lot of questions.

 

[kyudizky]

Re: 90 HP Johnson Questions

So the stator has probably gone, and not the voltage regulator? Is a volt regulator and a rectifier the same thing?

 

[petryshyn]

Re: 90 HP Johnson Questions

If your motor came with power TnT, then it has a Regulator/Rectifier assmy which is in the picture. Your charging system relies on the stator under the flywheel, Regulator/Rectifier (rectifier only if no TnT) and associated wiring. You must troubleshoot to identify the problem.

 

[kyudizky]

Re: 90 HP Johnson Questions

I don't think it had power TnT from the factory due to the M in the Model #(J90MLCRD) So i think it been added. If its been added i assume it still has the regulator/rectifier. I will check when I get home.

How would I go about troubleshooting?

Again, I am not familiar with these at all. While I do not like having problems with my motor, i am enjoying learning my way around them.

 

[spingley]

Re: 90 HP Johnson Questions

If it came from the factory with power Tilt and trim then I think it would have the rectifier/regulator like in the picture posted above, it is mounted on the top of the engine, if it came from the factory with manual T&T then you will have a round rectifier only, like mine, that is located on the RH side next to the wire terminal strip. I have the same situation as yours, I have the M in the model # but I also have power T&T, and I only have the round rectifier on the side of the engine.

 

[kyudizky]

Re: 90 HP Johnson Questions

any ideas on how to troubleshoot the the stator and regulator/rectifier?

 

[Chris1956]

Re: 90 HP Johnson Questions

The stator will put out AC voltage, when the motor is running. There is a spec for voltage as wel as ohms resistance for the stator coils in the service manual.

A voltage regulator is harder to test, and is ofter unnecessary, since they usually either work or don't. If the stator is good, and the battery doesn't charge, either the VR or rectifier (whichever you have) is bad.

Rectifiers may be checked using a analog multimeter. Each adjacent pair of connections on the rectifier will pass voltage (zero ohms resistance) in one direction, but not the other(infinite resistance). Use the multimeter leads, meter set to RX1 Ohm scale. Test two adjacent terminals. Note the Ohmmeter reading, and switch the leads.

 

[emdsapmgr]

Re: 90 HP Johnson Questions

How does the tach in the boat work? The tach is driven off the charging side of the stator. If the tach does not work or is erratic, you probably have an issue with the rectifer/regulator. Look there first. Unlikely a bad stator, but always possible. Your new manual will lead you through the diagnosis on your charging problem. Your Stratos may well have been factory rigged and the original OMC engine was changed for some reason by the prior owner. Same controls/different engine. Should work fine.