1989 Evinrude 150 Tach/Rectifier/VRO/ issues

[Sportfisherman 2100]

Maybe someone can point me the right direction:

My 1989 Evinrude 150 has intermittent Tachometer operation and nothing stellar in the battery voltage meter readings.

I've read a BUNCH of the threads on these two being symptoms of a faulty Rectifier or loose wiring.

A little history: The previous owner had to have the powerhead rebuilt. (not sure what happened)

Current Symptoms:

Engine was a bit hard starting, when it does start and warms up, ran fine. Good Power, top end speed good. Tachometer intermittent. 0 or proper RPM readings but on and off with no pattern or predictability.

I replaced the batterys with heavy duty Marine Batterys (not neverstarts) and am using hex nuts on the terminals.

The warning horn will come on occasionally, if I slow down, it usually goes off. Oil tank is full and water is "peeing" out of the tube and feels warm but not hot to the touch.

Something new yesterday. While under power, (no warning horn or other issues) the engine suddenly slowed down and then stopped. When I started it back up, it ran fine. Fuel pump ball was still pressurized. Ran quite a while, then warning horn. Slowed down, warning horn went off. Picked up speed again and after a bit, engine slowed down and stopped again. Idle is now very rough and starting difficult. High Speed it seems to run ok (and still lots of power till it stops)

Repeated the above several times. Finally, to get back to the launch (about 15 miles) I only accelerated about 1/2 speed and it ran all the way in with no issues.

QUESTIONS: Does the oil injection pumpl run off the tach signal? If so, when there is no signal (ie: Bad Rectifier) would that cause the injection system to not work which in turn sounds the alarm horn? (I have not read this addressed in any of the threads. Just that the alarm may go off if the tach is intermittent, not what the alarm is sensing) IF (shudder) the injection pump is not working, would that cause enough friction to stop the motor? (I'd think the Cyl's would be scored but looking through the spark plug holes with a bore scope (i'm a shooter) they do not look scored) Would a faulty rectifier cause the engine to run rough at idle and slow speeds? Lastly.... How do I tell if the rectifier is a 10am or 35 amp? And... on the 1989, is it located on the block on the left hand side, (boat left hand) or is it under the fly wheel.

OK... Thats it. I do not have a peak voltage meter to do a bunch of Grey / yellow / grayish Yellow / and Yellowish gray wire readings.

THANKS!

Andy

 

[Sportfisherman 2100]

Re: 1989 Evinrude 150 Tach/Rectifier/VRO/ issues

One more question, will a 1979 235HP Evinrude drop on in place of my 1989 150? Steering, shift, and wiring connections, are they the same?

 

[emdsapmgr]

Re: 1989 Evinrude 150 Tach/Rectifier/VRO/ issues

If you are going to swap the entire engine, they will swap. The 79 won't need the separate oil tank. Also, the 79 has the older 3-wire trim system-which has a separate trim box that mounts under the rear splashwell. You can't just swap the powerheads. You state that you have a warning horn. Perhaps you can be more specific. That engine has 3 types of warning horns: 1. constant horn-overheat or fuel restriction, 2. constant, repetitive beeping-oil mixing problem, 3. beep every 15-20 seconds-low oil warning. The coils in the stator make two distinctly different (separate) types of electrical power: the ignition is run from one set of coils. The battery is charged from another (different) set of stator coils (these are the coils that send the signal to the tach.) The large 35 amp charging system uses the vented flywheels-you can't miss them. Looks like none of the 150 engines in 1989 had the larger 35 amps system-only found on the 175's.

 

[Sportfisherman 2100]

Re: 1989 Evinrude 150 Tach/Rectifier/VRO/ issues

THANK YOU for the reply. I would swap the entire engine if it happens. I'd guess the trim Box can be moved from the donor boat. The boat with the 235 has a double control helm, (not sure how else to describe it. The boat with the 150 has a single. I've heard that it was recommended to use the double control on motors with over 150 HP.


The warning horn... This isnt a steady horn, its a beep beep beep that varys with engine RPM. Oil tank is 1/2 - 3/4 full. Could it be a vacuum or fuel pressure sensor that is getting intermittent pulses from the rectifier/tach feed?

Non vented fly wheel here. Standard 10amp system. AND... I learned today that the motor is actually a 1988. I was a year off on the age.

If I keep this motor on the boat, I may disable the VRO and go straight mix. Any issues with doing that?

THANKS!

If you are going to swap the entire engine, they will swap. The 79 won't need the separate oil tank. Also, the 79 has the older 3-wire trim system-which has a separate trim box that mounts under the rear splashwell. You can't just swap the powerheads. You state that you have a warning horn. Perhaps you can be more specific. That engine has 3 types of warning horns: 1. constant horn-overheat or fuel restriction, 2. constant, repetitive beeping-oil mixing problem, 3. beep every 15-20 seconds-low oil warning. The coils in the stator make two distinctly different (separate) types of electrical power: the ignition is run from one set of coils. The battery is charged from another (different) set of stator coils (these are the coils that send the signal to the tach.) The large 35 amp charging system uses the vented flywheels-you can't miss them. Looks like none of the 150 engines in 1989 had the larger 35 amps system-only found on the 175's.

 

[emdsapmgr]

Re: 1989 Evinrude 150 Tach/Rectifier/VRO/ issues

Doubt the warning horn is related to the output from the rectifier/tach lead. A fuel vacuum warning horn would be constant. Your horn probably relates to a problem with the fuel pump itself. At this point, I'd be premixing the oil in the fuel till you can get the warning horn sorted out. You may be referring to a dual cable steering setup. It is recommended to use a dual cable setup at 150 hp and up. If you swap to the 235, it's a good idea to upgrade to dual cable-or go to straight hydraulic steering.

 

[Sportfisherman 2100]

Re: 1989 Evinrude 150 Tach/Rectifier/VRO/ issues

Ok... I replaced the Rectifier/Reg. and now the tach works properly, no warning horn, and the volt Meter reads between 13 1/2 and 14 volts while running.

BUT... Its ROUGH at an idle and up to about 2000 RPM. Max RPM is 4800. I mixed the fuel with about a 50-1 mix while sorting this out and left the VRO system intact and am monitoring the oil usage from the tank to insure oil is pumping. (should be running about 25 - 1 this way, like a break in mixture)

I also changed the plugs to new plugs, standard Q series Champion. (I dont remember the # but they are the recommended plug).

Lots of power on the top end, quick out of the hole. Before running it on the lake, I did a compression check. Two weak cyl. on the lower left side. Middle one about 60 psi and bottom one 80. All others run 90 even. New Compression gauge but I cannot verify its accuracy.

Any ideas about the bad low end? I've not pulled spark plug wires one at a time or used a spark indicator to see if any of them are misfiring.

Top speed, trimmed out, Fairly large boat, Lund 21' Cuddy Cabin, is 36 MPH (GPS) which I think is really pretty good.

All ideas appreciated.

THANKS!

If it would idle smooth I'd be happy as a clam.

 

[emdsapmgr]

Re: 1989 Evinrude 150 Tach/Rectifier/VRO/ issues

I would think normal compression on that engine is in the 95 lbs range. A general guideline is that all cyls should have compression within 10% of each other. You have one which is outside that guideline. I'd be especially concerned about the 60 lbs cyl-there is something going on inside which you need to look at. May not be a good idea to continue running it till you better understand it. Pull the head and check the cyl seal ring on the head gasket. May be a simple fix. Could be that the 80# cyl has the same problem. While you are in there, make sure the rubber water diverters are in their proper location and fuctioning properly.