I have a 1990 150 Evinrude on the back of a 89 175 Skeeter. My tach bounces all over the place/ On minute it's reading correct the next it's 0. I assume I have a loose connection. Can someone help me with the pick-up is or connetions I should check.

thanks

Quick question...do you put a cell phone near the tach? I did and had the same symtoms. The phones' frequency ruined the tach and I had to replace it. I thought this was BS till I started talking with others on diff. forums and found this to be true. You can check the conections on the back of the tach, just power, ground, light and altenator.

Bald, here is a link for ya'. As TXSport said, phones can run them. Check the link on cell phone on the page, also.
http://www.outboardrepairs.com/tachometers/

Could be the Reg/Rect going bad. The tach signal comes from there, Grey wire I think. What's your voltmeter doing?

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steve pine

Stays steady - no movement

Bald1- Steady no movement as in not charging, or steady no movement as in the battery charges to almost 14 volts and there it stays? If it always reads below 13 volts, I don't think it's charging.

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steve pine

No movement as in not like the tachometer bouncing between 0 and 5000. The gauge does move when the motor is running and charging.

Bald1 - That sorta answers the question.

When the motor is running, with no electrical devices loading it down, the battery should charge to about 13.8 volts. If you operate the trim/tilt or something that will put an electrical load on it, the battery voltage will drop toward 12 volts and then move back up as the Reg/Rect charges it back up.

You don't say what the voltmeter is reading, but if you have a habit of putting a charger on the batter between use, I'd guess it's about 12.4 volts after you start the engine.

I don't know the specifics of your 1990 engine, but if it's like my 1994, here's how it works. There is a stator on the motor with pemanent magnets under the flywheel. As it rotates, the magnets pass coils and this action creates an AC voltage. The voltage goes to the rectifier part of the reg/rect to become DC voltage. The regulator keeps the voltage at about 14 volts and outputs it to the batter on the Red wire. The pulses from the stator that arrive to the reg/rect are passed on to the tachometer via the Grey colored wire.

If you aren't getting charging output and your tach is jumping around or not working, it's a pretty good bet the Reg/Rect has gone bad or is going bad.

There was a post some time ago that led me to troubleshoot the reg/rect on my boat based on the above conditions. These were also the conditions on pdeibert's engine and we changed out the reg/rect and got it fixed.

It appears to be a somewhat common problem from all the searching I've done. I'll try to remember to check my manual this weekend and see if it covers 1990 engines.

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steve pine


[This message has been edited by spine (edited 10-29-2003).]

I have never seen a more complete detailed answer. Thank you so much!

I did read in my engine manual something regarding the rectifier but I thought it was pertaining to older motors, maybe not. The one thing the manual does not describe is where the rectifier is located so I can decide whether this is a job I want to attempt.

I am going to take reading on the voltmeter per your suggestion tonight - loaded / unloaded / charging

Again, thanks so much! Hope I can return the favor!

Rect/Reg is either mounted on top the block just above the cylinders, (water cooled), or mounted on the side, (not water cooled). If it's on top, it's under an plastic cover and the power pack. I'm guessing it's on top.

In your manual, look in the electrical and/or charging system trouble shooting section or in the index under Regulator, Rectifier or Regulator/Rectifier.

If you start disconnecting wires, disconnect the battery first. The Red wire goes directly to the hot side of the starter and you don't want to short anything out.

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steve pine

I can attest to spine expertise on this matter.
He trouble shot mine and even performed the repair job in exchange for a great day of striper fishing.
If your not electrically adept, I wouldn't try it.
All those wires scared the hell out of me....

Thanks pdeibert I appeciate to recomend. There is no question by spine's responce he knows what he's talking about. Electrical doesn't bother me. Absolutely, disconnect the battery. I am real close to B&B Marine in Pottsboro. I'll probably go by and see if they have a rectifier in stock. This will give me an idea what I'm looking for. Sorry, I don't do striper fishin but I sure do lbm, crappie and sand bass. The same offer would sure apply here to a day on the water with spine.

thanks again spine

I appreciate the nice remarks. As I've told Paul before, I'm an expert only because I've seen the problem and also because my first replacement went bad soon after installation and I went crazy for 3 months trying to prove it wasn't something else before I sank more bucks into a replacement. Fortunately, the current one is working fine.

I checked my manual, it's for 1991-1994 motors. Some side mounted ones are water cooled also. You should be able to track it down from the terminal block for all the wires. If you've got a shop manual, I'm certain there're instructions.

My office is in Richardson and I occassionaly visit Raytheon in McKinney. If you're boat is in McKinney, I'll be happy to stop by and give you my two cents worth if we can hook up one afternoon or evening during the week. Just drop me an email and let me know.

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steve pine

Thanks for the offer.

I'm going take a look at it in morning. Unfortunately I'm lasooed into going to Canton late morning then next week I'm out of the country for a week. If I can get the rectifier from B&D today. I beleive I can get it intalled in the morning. If not I'll drop you a line. Is there somewhere in the forum where I can find your email address? Or just let me know.
My email
steve.vanleer@metso.com