Can't go over 2500 rpm's?

macojoe

macojoe

Administrator
Ok we got the shifter fixed, works like a charm!!

Now its time for the next issue!! Can't get more the 2500 RPM's on the motor when in the water in gear under a load??

We did a compression test, fine in all 6, Great spark in all 6, Motor starts and runs when 3 plugs are unplugged on left, and starts and runs when 3 plugs unplugged on the right.

BS and I are sure it is electric something, but WHAT??

Any Ideas guys??

Thanks!
 
maybe when fixing the reverse linkage something got out of adjustment w/ the throttle linkage [???] or the timing advance linkage?
 
So this is a different motor than the one that was on the boat last week, correct?
Your signature reflects an '87 and this one is an '86.
Has the VRO been gutted? Knowing you, yes.
The parts catalog brings the model up as E225TXCDA if that matters.
Like BS was saying, not sure about the low oil - low rpm safety thing, what year it was implimented but seems to me it was the first year they came out with the VRO system.
-----------------------------------------------------------------------------------------------------------------------------------------------
post_old.gif
Today, 05:01 PM
BY bigshrimpin
user_offline.gif

God
Join Date: Mar 2003
Location: Davis, CA
Posts: 1,270


icon1.gif

Well . . . the shift problem is fixed!! Now onto the the next problem . . . the motor won't go above 2500rpm in gear (with a load). I think it's probably the stator, but I'm no OMC guru. I believe the motor is an 86 or 87 and slow mode didn't happen till 1988/89??? any suggestions. There is decent spark on all 6 clylinders when cranking, and compression is even in all 6. We pulled plug wires on one side and the motor will start . . . and then we did the same on the other side and the motor started, so I don't think it's a power pack. Linkage is advancing through the full range of motion. I'm 100% sure it's electrical, but I'm not sure what else to try beside breaking out a multi-meter and going through each component.
Last edited by bigshrimpin : Today at 05:07 PM.
-----------------------------------------------------------------------------------------------------------------------------------------------
My '84 had the capability to change to dual fuel pumps but from '86 on out I don't see that option.
I'm not sure how to defeat the VRO system and use the fuel pump disconnected from the oil pump.
It sounds like the VRO system is actually working and preventing it from running over 2500 rpms.
You have an almost identical motor to compare to.
That year model had a remote mounted reservior for the oil, is it possible to have a pair of wires that need connecting to simulate a full tank of oil?
 
Last edited:
So this is a different motor than the one that was on the boat last week, correct?
Click to expand...
Nope same motor, just got the numbers off and looked it up to make sure what it is, and 86 is the deal. And yes VRO is gone long before I got the motor.

Thanks
 
http://www.outboardignition.com/page32.asp

S.L.O.W. – Speed Limiting Oil Warning system. Limits the RPM of the engine to approximately 2500 RPM in
order to reduce the damage to the engine caused by a no oil or overheat condition.

Engines with S.L.O.W.
Engine will not rev beyond 2500 RPM:

1. Use a temperature probe and verify that the engine is not overheating.
2. Disconnect the tan temperature wire from the pack and retest. If the engine now performs properly, replace the temperature switch.
3. Make sure the tan temperature switch wire is not located next to a spark plug wire.
 
Just back in from the water, Same thing :cen: Won't go over 2500??

Disconnected the tan wires and it had no effect :cen:

Oils has been disconnected for years so I am sure there is nothing there.

Tied to a empty mooring and cked things out, motor starts and runs great, raced the engine in neutral and it gets full throw and full rpm's, but as soon as you put in gear and load up the motor its still at the 2500??

Why is it for the last few years I get half way threw the season and bam I get screwed??
 
Check

Please check for spark on all cylinders, Double check all connectors to your packs; Looks like you are running on 3 cylinders not 6 may be one pack is blown. You will have to test will find it. Also observe the movement of the advance (under fly wheel) make sure it moves freely back and forth. Ferm, Skool where are you guys ? Help !!
 
Spark ok on all 6 plugs, all connectors are good, all linkage is moving to there stops, throttle, timing advance, and choke.

Talked to skools on the phone 1 hour ago, he thinks wire harness, or stator?? But says to do the wire harness first as I have some issues there.

I have a brand new harness for the boat side, and BS is going to bring me the motor side. But I have to wait for Friday for him to get here. That's ok going to blow tomorrow and rain all day Thursday.
 
I don't understand how this problem presented itself without some prompting.
Did any wires somehow get arced, grounded or shorted? Normally that would damage a powerpack.
If it was the magnets shifting in the flywheel it wouldn't run or at best run like crap.
Whatever it is, at least it happened in the yard and not offshore.
Look at it that way.
 
BS and I were fixing the shifter and had the cowling off and hanging, that might have broke a wire waiting to happen?? There seems to be a few like that, that the old owner just taped up.
 
Check

Disconnect both tan wires and ground one at a time to the lock with the key switch on, your buzzer should sound. If no buzzer then its possible the tan wire is currently shorted out shorted (no buzzer working) and is holding the motor within the "low load range of 2500 rpm”?
Also can you turn the prop freely in Natural? Maybe the lower unit is broken and is locking? Reason why I mentioned the lower unit is because of the shifting issue.
 
The lower unit is fine right now.

No buzzer so that test isn't going to work, but the book says to disconnect the tan wires from the censors and try it, I did today and still the same.

Thanks!!
 
Re

The TAN wire is spliced in the harness you just can’t see it, it connected back to the power packs to limit spark in the event there is a short (over heat, low oil etc) to protect the engine. If this wire is disconnected but still creating a ground it will continue to act like it should in this case limiting you to a low RPM, the other is the buzzer since you don't have a buzzer maybe just maybe this part of its function is working! My thoughts are to unplug the round connector and tone the tan wire out, single pin from the connector back to both ends of the TAN wires make sure it has no connection or fault to ground hope this makes some sense. Also it will not hurt to lubricate the round red plug connector when you unplug it. I really don't think it is your Stator period.
 
Thanks again!!

There is a wire in the red plug that rotted out, BS found it and it does go to the tan wires!! So you might be right on the money!!

BS is coming Friday with a new wire harness for the motor, I am going to replace the boat side wire harness tomorrow cause I have one here.

Hopefully this will take care of the problem?? It has to be something simple like a wire cause everything was perfect till the sifter broke. and we disturbed wires.
 
Just remembered.
Usually you can crank an engine without the harness to the shifter connected and run but not be able to shut it off.
This may help localise the problem.
Start the engine, then unplug the harness under the cowling and see if the problem still exists. In order to shut it off, you must plug it back up in order to use the key switch as the kill or off position.
Unless the wire you are describing is in that harness connection.
 
Yes the red round one inside the cowl that goes to the control box and to the engine harness, about 1 1/2" round.
We have checked motors prior to purchase if controls were not available, say on the back of the boat or in a drum without the control box attached by jumping the starter solonoid and manually choking the engine. Only problem, there is no way to kill the engine except to choke it down or unplug the gas and let it run out.
Anyway...
This might let you localize it to the control box wires or the engine harness wires or not without replacing them.
I can't imagine it being either based on the way the VRO was wired but I have no experience on this.
Won't cost nothing but a trip to the ramp, at least you can experience how easy it is to steal a boat without a key.
 
You must log in or register to reply here.
Back
Top