trim tilt motor continously running

[cstewa]

sorry to keep harping on this...but I am a complete newbie and can't figure this out.

with the ignition on.... the tilt/trim motor continues to hum/run. I have tried taping on the solenoid thinking it may be stuck but to no avail. I have run the outdrive up and down several times but it continues.

I am wondering if the oil may be low. would this cause the electric motor to continue to run?

I am also not sure how to refill the oil. there is a cylinder in a very difficult position to reach...mounted on the back hull. It's long, vertically mounted with two small bolt head screws holding the lid on. It says on the cylinder refill oil before use...so I am sure this it.

Do I just remove those bolts and poor it in the top??..I kind of expected a reservoir. and this thing is really difficult to reach.

Now.. all the way on the other side of the hull where the continuously running electric motor is...there is an oil filter mounted to the side of the hull...in line with the continuously running motor. I just don't see a refill reservoir in this region..

Any help much appreciated...thanks. By the way it is a Volvo penta dp drive...not sure where to find the serial number?

 

[thrasher]

Re: trim tilt motor continously running

Are you sure its the trim motor that is running? You say you can raise and lower the stern drive. If the motor was running continously the stern drive would go to one mechanical extreme and jam there, you wouldn't be able to raise or lower it.
From your description it sounds like the stern drive is not going up or down, so I suspect its another motor that is running not the trim motor? Could it be the fuel pump?

Gary

 

[cstewa]

Re: trim tilt motor continously running

well...I like I said I am a newbie....It must be the fuel pump....would it be normal for the fuel pump to hum like that?

Is there an oil pump? The is a filter that looks just like the oil filter in line with this pump...maybe I can post a pic.

 

[RCSConstruction]

Re: trim tilt motor continously running

I am a "newbie" too and heard the same thing but it was my blower motor.
Maybe your hearing that too???

 

[cstewa]

Re: trim tilt motor continously running

Ok...second look just now...I think it is the fuel pump...is normal for it to make a hum like this?

I was going to hold off on sticking it in the water this weekend...but I think I am going to go for it...

first boat and I am pumped!

 

[superpop]

Re: trim tilt motor continously running

If it is the fuel pump and it is continually running even with the motor not running then you have a big problem. The Fuel Pump is generally very quiet so you should not hear it. If it is running all the time though you need to check your oil level and make sure your carb is not defective, if it is it could be dumping gas into your crankcase which can lead to a big boom. Like I said though the fuel pump is normally very quiet. Follow the lines that go into and out of it and figure out what it is. Also a year and fuel delivery type such as fuel injected or carbed would help as well.

 

[cstewa]

Re: trim tilt motor continously running

Ok...could it be that the electric fuel pump is trying to prime it self....there is not much gas in the tank...the oil level is fine.

I have attached two pics....the pump that is running is mounted on the left of the engine compartment and black and is inline with a white colored filter...there is a fuse with red electric wires mounted above it....two lines go to the holley carb. It's a merc 420.

the motor was ran 1 week ago with muffs on and ran fine...

 

[thrasher]

Re: trim tilt motor continously running

That does look like a fuel pump, as you have a carburettor it could be normal for the pump to be running all the time the ignition is turned on. It should stop when you turn off the ignition..
There are two fuel delivery systems used on carburated engines. The first is a single supply line where the pump delivers fuel to the carb, the pump attempts to deliver fuel as required by the carburettor and the fuel supply is not constant.
The second system is a two line system, where the pump continously pumps fuel to the carb, but there is a return from the carb to the tank so that any fuel not required by the carb returns to the gas tank. This second system will have the pump running all the time, regardless of the fuel level. The single supply system will only run continously if you have run out of gas as you suggested..
I suspect looking at the pump in your picture that you have the two rail system, so a continously running pump is normal!! As long as it stops when the ignition is turned off.

Gary

 

[Coors]

Re: trim tilt motor continously running

If it is going tic tic tic, then it is probably ok; if running at a hum, seems you have a problem, either no supply, or a bad leak between it and the carb; or the float is stuck open.

 

[Don S]

Re: trim tilt motor continously running

It's a fuel pump, and they do RUN, not just tic-tic-tic. The problem is, it shouldn't run with the ignition switch on and the engine not running.
It MUST be a marine fuel pump, and it must be wired in so that it will not run if the engine is not running. Merc uses an oil pressure switch, no oil pressure, the pump doesn't run.

 

[Bondo]

Re: trim tilt motor continously running

Ayuh,........ That looks like a Carter Electric Pump.......

I'm not sure of it's Marine rating,.......
But,......
As noted by Don,.........

It's Wired All Wrong...........

No Doubt,.......
A little Creative Engineering by a PO who Didn't come to iboats for His info.............

For about $20.00,+ an Hour or so,......
You can make that Explosive Issue a Safe 1.........

 

[cstewa]

Re: trim tilt motor continously running

The boat floated and ran...engine sounds awesome...extremely fast boat. didn't cruise to long as I found some other issues.

Ok...it is a two line system ...the fuel pump does run while the ignition is on and but the motor is not.....so is the two line system inherently unsafe? I am willing to spend the money to make this a safe boat.

the boat is currently at the marina for low voltage issues and a leak at the intake manifold. I have asked them to take a look at the running fuel pump...I hope they have some clue...but I am not sure that they do.

Where can I purchase a repair manual or users manual for the Mercruiser 454/420.

 

[Don S]

Re: trim tilt motor continously running

Where can I purchase a repair manual or users manual for the Mercruiser 454/420.

The 420 is a High Performance engine and you need Merc service manual HP#1. The merc PN for that manual is 90-817110
Here is one place http://www.stemtostern.com/catalog/displayproductdetails.asp?DepartmentInventoryRefID=393263

Also, here is how Mercruiser now sets up their electric fuel pump thru an oil prressure switch so the pump does not run all the time. This is a REQUIERED safety feature. Even if it isn't requiered, it would be good common sense to have.

 

[cstewa]

Re: trim tilt motor continously running

Thanks Don.

That diagram looks a little intimidating. I want to get this thing right though. Surely the marina should be able to do this for me. If not maybe I can find someone with a little more knowledge than me to help.

Oh and thanks for the link to the merc manual.

Do you think that the engine already has an oil pressure switch or is this a fairly new way to wire up the fuel pump?

 

[Don S]

Re: trim tilt motor continously running

I'm not familiear with the 420, so couldn't tell you if there is an oil pressure switch or not.
It's not hard to wire yourself, and the oil pressure switch can be purchaced from NAPA. The rest is just wiring.
One wire from the start soleoid to power the pump when cranking. The other from an ignition (Purple) wire to the oil pressure switch and on to the pump.
Here is that same drawing with the clutter taken out.

 

[cstewa]

Re: trim tilt motor continously running

http://www.go2marine.com/product.do?no=115358F

This may be the oil pressure switch that I need...I am not sure that the engine comes with one...and I don't know where it goes.

but there must be some oil pressure sending unit to run the oil gauge. So that makes me wonder if there will be room for another switch...in other words I will have no clue as to whether to put the thing.

By the way Don....thanks for putting up with newbies...leaning this stuff really is great.

 

[cstewa]

Re: trim tilt motor continously running

Here is another possibility

http://www.amazon.com/Holley-12-810-Electric-Safety-Pressure/dp/B00029JC7G

 

[thrasher]

Re: trim tilt motor continously running

Just to answer your other question, the two rail system is not the slightest bit more dangerous than a single rail system. Both systems have their advantages and disadvantages, your only problem is that someone has wired the fuel pump into the boat as if it was in a car. Car's have the fuel pump operating the instant the ignition key is turned on, boats only operate the fuel pump when the engine is running or the starter motor is engaged..
You just need to correct the positive feed to the fuel pump and you are good to go..

Gary

 

[cstewa]

Re: trim tilt motor continously running

Thanks thrasher..

I've got to get this fixed...

 

[Don S]

Re: trim tilt motor continously running

Yea, that switch would work, but Merc has one (PN 87-864252A01) that lists for $26.25.
There are 2 places the oil pressure switch can be. Merc Tee, them in just over the block fuel filter housing, or up next to the distributor is another location.