Belt Size or Part # for a 1985 Mercruiser 3.0 Alpha One Gen One

[1985 Century Mustang]

I recently got my boat for free from a friend, its a 1985 Century 20' Mustang II, its been sitting in his driveway for 12 years inoperable.
I rebuilt the carb and put an electric fuel pump on her. It starts and idles perfectly etc

Question: Does anyone know the belt size or what belt I need for a 1985 Merc 3.0 Alpha One Drive.140 hp. Belt is loose and could be changed. Engine photo below. Thanks.

 

[dubs283]

Remove the belt and take it to your local auto parts store, they ought to be able to match it

Your fuel pump setup is a recipe for disaster. You need pressure rated fuel line and connections between the pump and carburetor along with some type of automatic safety switch that will eliminate power to the pump if/when the engine ceases to run and the ignition is still powered. Mercruiser used an oil pressure switch on oem packages

 

[1985 Century Mustang]

Remove the belt and take it to your local auto parts store, they ought to be able to match it

Your fuel pump setup is a recipe for disaster. You need pressure rated fuel line and connections between the pump and carburetor along with some type of automatic safety switch that will eliminate power to the pump if/when the engine ceases to run and the ignition is still powered. Mercruiser used an oil pressure switch on oem packages

I know and I agree, I just recently mounted it to the bilge area. So it's very secure now. Everything is tight. That setup was temporary. Thanks

 

[Scott06]

I know and I agree, I just recently mounted it to the bilge area. So it's very secure now. Everything is tight. That setup was temporary. Thanks

MerCruiser 140 GM 181 I / L4 1982-1986 Crankshaft, Camshaft, Water Pump (140-3.0l / 181 Cid) Parts

MerCruiser 140 gm 181 i/l4 1982-1986 crankshaft, camshaft, water pump (140-3.0l/181 cid) parts. Buy a genuine Mercury Quicksilver or aftermarket part.

www.marineengine.com

Number 14 in there is the belt - there are two listings one for non PS and one for PS ..

two points to consider-

understood you mounted the fuel pump but did you catch his comment on the oil pressure switch to power an electric fuel pump? This keeps the pump from running if the engine isn't running but ignition is left on

Also looks like some one put plywood over the original decking? If thats the case would check that the stringers and transom are sound and not rotten before putting any money into this.

 

[1985 Century Mustang]

Remove the belt and take it to your local auto parts store, they ought to be able to match it

Your fuel pump setup is a recipe for disaster. You need pressure rated fuel line and connections between the pump and carburetor along with some type of automatic safety switch that will eliminate power to the pump if/when the engine ceases to run and the ignition is still powered. Mercruiser used an oil pressure switch on oem packages

The newly installed electric fuel pump is powered up only when key is turned on. I ran it to the positive terminal of the starter. And seems to function accordingly. Hence, I may install an inline fuse also for the electric fuel pump. As far as The oil pressure light staying on, is this because of the block off plate where the mechanical pump was? I'm not understanding. Thanks.

 

[1985 Century Mustang]

MerCruiser 140 GM 181 I / L4 1982-1986 Crankshaft, Camshaft, Water Pump (140-3.0l / 181 Cid) Parts

MerCruiser 140 gm 181 i/l4 1982-1986 crankshaft, camshaft, water pump (140-3.0l/181 cid) parts. Buy a genuine Mercury Quicksilver or aftermarket part.

www.marineengine.com

Number 14 in there is the belt - there are two listings one for non PS and one for PS ..

two points to consider-

understood you mounted the fuel pump but did you catch his comment on the oil pressure switch to power an electric fuel pump? This keeps the pump from running if the engine isn't running but ignition is left on

Also looks like some one put plywood over the original decking? If thats the case would check that the stringers and transom are sound and not rotten before putting any money into this.

The plywood is all new as well as the stringers, all the original stringers and decking were removed/gutted.

 

[Scott06]

The newly installed electric fuel pump is powered up only when key is turned on. I ran it to the positive terminal of the starter. And seems to function accordingly. Hence, I may install an inline fuse also for the electric fuel pump. As far as The oil pressure light staying on, is this because of the block off plate where the mechanical pump was? I'm not understanding. Thanks.

The coast guard requires a device to shut off electric fuel pumps in the event the ignition is on but engine stops running- engine stalls or someone bumps the key to ignition on (run), otherwise the fuel pump will be running and potentially overfill the carb float bowl etc.

So, in addition to using a marine rated fuel pump, what the manufacturers like mercruiser have done since the 90's is wire the fuel pump through an oil pressure switch (nothing to do with the oil light) so if the engine stops running power supply to the fuel pump is interrupted. Also the fuel pump will get power off the starter during cranking. I'm sure you can find some threads here on it as many folks have needed to wire this up. Here is one

3 prong oil pressure switch elec. fuel pump wiring

hello, changing from 1988 mercruiser 5.0 lx /alpha 1 gen 1 ,to new gm 5.7 vortec motor with electric fuel pump. wire from I terminal goes to ? and the S terminal wire goes to ? have a thunderbolt4 ignition with delco est distributor ,My confusion is the purple wire to neutral safety switch...

forums.iboats.com

Good news on the floor and stringers. Have seen too many folks get burned on that one

 

[Scott Danforth]

The mechanical pump is under $50 and will last decades. A marine rated pump, oil pressure switch, relay, relay socket and wiring will cost over $110.

That pump is against USCG regs

 

[nola mike]

The mechanical pump is under $50 and will last decades. A marine rated pump, oil pressure switch, relay, relay socket and wiring will cost over $110.

That pump is against USCG regs

As is the inline filter

 

[1985 Century Mustang]

I got the belt off, brought it to an auto parts store for sizing. What I thought was a 20 min job turned into a 3 hour job,,, in mid 80 degree temps in April. WTF

 

[Scott Danforth]

on the 3.0, make sure you check alignment when you are done since you have to remove the front mount

 

[1985 Century Mustang]

on the 3.0, make sure you check alignment when you are done since you have to remove the front mount. I didn't remember the front mount.

I didn't remove the front mount it stayed intact.

How do you check alignment anyway if so, can you be specific.

 

[1985 Century Mustang]

The mechanical pump is under $50 and will last decades. A marine rated pump, oil pressure switch, relay, relay socket and wiring will cost over $110.

That pump is against USCG regs

Ya got me thinking. I may run the positive line to the oil pump circuit. I'll look into it today.

 

[Scott Danforth]

I didn't remove the front mount it stayed intact.

How do you check alignment anyway if so, can you be specific.

every year (annually or every 100 hours), or any time you touch an engine mounting bolt, you must check alignment

 

[1985 Century Mustang]

The mechanical pump is under $50 and will last decades. A marine rated pump, oil pressure switch, relay, relay socket and wiring will cost over $110.

That pump is against USCG regs

Thanks, I just bought a mechanical pump on ebay. He is a preferred seller. $28.00

 

[Scott Danforth]

Thanks, I just bought a mechanical pump on ebay. He is a preferred seller. $28.00

is it a carter? or a chinesium no-name?

the Carter was OEM

 

[1985 Century Mustang]

is it a carter? or a chinesium no-name?

the Carter was OEM

I'm not sure, but the seller is from NJ, right near me. Eventually I'll get a good brand name mech pump. I just can't afford to keep nickel and diming parts at the moment. My partner is AWOL, so I'm dumping the bucks in the boat left and right. Next year I'll do the better mechanical pump. I'll keep the electric pump onboard just in case of the mechanical pump failure.

 

[dubs283]

I just can't afford to keep nickel and diming parts at the moment.

Lol, seems to me this is exactly what you are doing

Napa supplies seirra parts. You can buy/order the correct components from them and only have to purchase them once.

FYI, save the fuel line connection from the old fuel pump. You will need it to connect the proper fuel line between the pump and carb. Your current fuel line setup based on the pictures while suitable for testing purposes is incredibly unsafe and probably illegal in some jurisdictions

 

[1985 Century Mustang]

Lol, seems to me this is exactly what you are doing

Napa supplies seirra parts. You can buy/order the correct components from them and only have to purchase them once.

FYI, save the fuel line connection from the old fuel pump. You will need it to connect the proper fuel line between the pump and carb. Your current fuel line setup based on the pictures while suitable for testing purposes is incredibly unsafe and probably illegal in some jurisdictions

Yes that's what I'm going to do. Being that the metal fuel line was already cut to modify for the electric pump, I'll use marine grade rubber fuel line to attach them together with good hose clamps.

 

[Scott06]

Yes that's what I'm going to do. Being that the metal fuel line was already cut to modify for the electric pump, I'll use marine grade rubber fuel line to attach them together with good hose clamps.

the steel line is just flared 3/8" tubing you could reflare it or use a compression fitting to reassemble it as well