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Oil injection overflow 225 V6 Excel

E

eggage1

New member
Hi:
I have recently purchased a 1987 Yamaha 225 Excel with the Precision Blend oil injection system. I tilt the engine to trailer the boat.
When I launch the boat and start the engine the pump does not shut off and the main tank on the engine overflows to the point where it pops the float out of the tank.
I removed and cleaned the remote tank (sludge) and the main tank. Also changed the filter on the remote tank. New oil added.
I removed the float at the main tank to test with an ohmeter. Float seems to be moving free with no sticking.
I tested the black wire to the white wire - continuity at the top or tank full position.
Tested the black wire to the brown wire - continuity at the mid position none at top or bottom.
Tested the black wire to the red wire - continuity all the time.

Tested float in a cup of oil and it shuts the pump off 3 out of 4 times. The fourth time it just keeps pumping.

Can anyone verify if these readings are correct?
If they are is there any way to test the control unit? (black box under the tank) or is it a process of elimination? Float then control unit?

I read many of the other posts on precision blend systems but most were newer engines or concerned with no oil pumping.

Thanks for any help.
Mike
 
The trim sender may be the cause. Does the trim gauge indicate correctly? It is supposed to prevent oil transfer it motor is in tilted position.
 
The trim sender on that 87 is not connected to the oiling system. They control box has a tilt sensor in it that shuts the oil off when the engine hits 60 degrees. Chances are that the control box is bad. (It has the oil tank emergency fill switch on it.)
 
Thanks for the replies. Replaced the float and it's been good for two runs. The old float checks out fine on the bench but possibly was sticking due to all the crap that was in the tanks. Time will tell.
The control unit does shut off the oil pump when tilted but that's the suspect if the problem continues.
I'll keep you posted after a few more runs.
 
Sorry for the delay in updating. I wasn't able to get out to test.

After three more runs the cause is still up in the air. The motor ran fine for two and then on the third I managed to shut the oil pump just in time. It was just about ready to overflow.

It seems that when arriving at the ramp and tilting the motor down after trailering when I start the motor the pump doesn't shut off. If I disconnect the remote tank pump and let the oil go down in the main tank to about halfway everything works normal after that.

I have cleaned the tanks and lines, changed the filter on the remote tank, and changed the float sensor on the main tank. Investigation continuing.

Chris - A question on the arrows you mentioned. The only arrows are on the tube that houses the float. They point in an upward direction. There are no arrows on the main tank to line them up with. Am I missing something?
Also this float does not seat at the bottom of the main tank. It is just suspended from the top. I had a newer motor that had a seat at the bottom of the tank for the float but this does not.
 
Latest update. 4 runs and all was fine. 5th run I got an alarm. Upon checking the main tank I discovered the oil level at the low mark.
Used the emergency switch to fill the main tank and all was fine for the rest of the day.
I'm going to replace the control unit ASAP.
 
Replaced the control unit. There is an extra wire that the instructions say to hook up to the pulser coil.
The old unit had no such hookup.
Does anyone know if this wire has to be run on a 1987?
 
Chris:
Not sure on the color. Boat is at the marina. Will check first thing in the morning.

Thanks for all your help.

Mike
 
The extra wire coming off the unit is white with a black stripe.
As per Yamaha customer service they say to hook up to
White with red stripe
White with black stripe
White with yellow stripe
These would be the three positive pulser coil leads. They are saying that the new pump needs to see the engine running.

Tried all three with no success. The new unit only pumps when you use the switch.
I am getting the input from the float but no pump.
Old unit still works but not reliably. Just about out of ideas.
 
Latest update. My conclusion was that the unit was bad.
The shop where I purchased the part checked the system and agreed.

Waiting for new control unit.
 
The shop is now refusing to make good on the control unit. They say no returns on electrical parts.
Motor working on old control unit for now. I'm searching on Ebay for an old style control unit.
Antone know where you can find these for sale?
 
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