Alpha One Start Issues

BuddyB77

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Joined
May 22, 2020
Messages
9
Hi Guys - new member first time poster here (be gentle!)
I'm sure you've heard this one before.
Have a Merc Alpha One Sterndrive (I think 1989, will get the serial number if needed), ran great last season, winterized (out of water for 6 months) and now it won't start.
I'm not overly technical but here is what I know.
Lots of crank on the engine, belts move but won't start up. All accessories are working properly.
Checked the carb - its dry with only faint smell of gas.
I do not hear the fuel pump at all when I turn the key.
Voltages are 12.3vdc at the battery and the circuit breaker. Solenoid, ignition switch and all other test points I could find are showing 8vdc.
If I had to make an ignorant guess I'd say the issue is with the fuel pump but the 8vdc puzzles me, I would understand if it was showing 0 (bad wire, short or part failure?) but I don't know why 8vdc and whether or not it can operate at that lower voltage.

For full disclosure - when I removed it from the water last season about 1/4 tank of gas left. I put the fuel stabilizer in but was not able to run it through the engine, filled it to the top with fresh gas as few days ago. I was told to see if I could smell "varnish" which would indicate the fuel had gone bad but I didn't get a varnish smell at all.

Normally I would take it into service but my job is gone due to covid so hoping its a minor problem.
Thank you in advance for any help!
Bud
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
I do not hear the fuel pump at all when I turn the key. ,you wont with a carb put a few oz`s directly into the carb and try to start it
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Hi BuddyB77 and: welcome: aboard.

Alpha One is the model of the drive. What we need to know is what engine you have. Merc put 4s, 6s and 8s in front of those drives, so until we know what the engine is (and please include the engine serial number), we can't offer much more than generic advice. It usually helps to tell us what fuel system and ignition system is on too. Merc used a variety of those as well. So, carb, 2 or 4 barrel. Ignition usually for the V6s and V8s it is Thunderbolt 4 or 5 for carbs engines, for EFI/MPI which ECU (MEFI1, MEFI3, ECU555, etc).

Cheers,

Chris.
 

BuddyB77

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Joined
May 22, 2020
Messages
9
Its a 3.0 4 cylinder, I'll get the serials tomorrow.
Thanks for the quick replies.
 

tpenfield

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Staff member
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Messages
17,624
If the engine is original to the boat (1989), I would think it is carbureted, not fuel injected.

Go for the basics . . .

Fuel - compression - spark.

>> You can test fuel with starting fluid

>> You can test for spark by exposing a plug wire or even a spark plug and visually seeing a spark while cranking.

>> Do you have an electric fuel pump? or mechanical?

Compression is probably OK, unless something dramatic has happened to the engine.

The serial # will help more specifically ID the engine, but it will boil down to the basics.
 

BuddyB77

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May 22, 2020
Messages
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P1040184 (1024x768).jpgP1040185 (1024x768).jpgP1040194 (1024x768).jpg Serial numbers attached
 

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BuddyB77

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more photos P1040183 (1024x768).jpgP1040188 (1024x768).jpgP1040191 (1024x768).jpgP1040196 (1024x768).jpg
 

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BuddyB77

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Joined
May 22, 2020
Messages
9
Carborated
Mechanical fuel pump I assume
I don't have any starting fluid - would putting a bit of gas directly into the carb do the same?
I will test for spark
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Yes, mechanical fuel pump. You have a points ignition system, and that's the first place I'd be looking. Points contact faces get a bit of oxidation on them and stop working... Check for spark, and if you have no spark, here's the link to a thread with exactly the same problem. Use the diagnostic info and drawings and diagrams in that thread to help you.

https://forums.iboats.com/forum/engi...3-0-mercruiser

Chris......
 

tank1949

Lieutenant Commander
Joined
Apr 4, 2013
Messages
1,759
Hi Guys - new member first time poster here (be gentle!)
I'm sure you've heard this one before.
Have a Merc Alpha One Sterndrive (I think 1989, will get the serial number if needed), ran great last season, winterized (out of water for 6 months) and now it won't start.
I'm not overly technical but here is what I know.
Lots of crank on the engine, belts move but won't start up. All accessories are working properly.
Checked the carb - its dry with only faint smell of gas.
I do not hear the fuel pump at all when I turn the key.
Voltages are 12.3vdc at the battery and the circuit breaker. Solenoid, ignition switch and all other test points I could find are showing 8vdc.
If I had to make an ignorant guess I'd say the issue is with the fuel pump but the 8vdc puzzles me, I would understand if it was showing 0 (bad wire, short or part failure?) but I don't know why 8vdc and whether or not it can operate at that lower voltage.

For full disclosure - when I removed it from the water last season about 1/4 tank of gas left. I put the fuel stabilizer in but was not able to run it through the engine, filled it to the top with fresh gas as few days ago. I was told to see if I could smell "varnish" which would indicate the fuel had gone bad but I didn't get a varnish smell at all.

Normally I would take it into service but my job is gone due to covid so hoping its a minor problem.
Thank you in advance for any help!
Bud
Switch (at helm) may have developed corrosion internally. Test input and output with meter. Neighbor had similar problems with his antique Mustang. New dash switch solved problem. Also, one of my boat's ignition breakers became defective and would not supply proper voltage/current to starter and it "ate" flywheel ring gear and starter teeth. Not good!!!!
 

BuddyB77

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Joined
May 22, 2020
Messages
9
Thanks for the suggestions, I will check all of that out.
I did try to start it by spraying a small amount of gas into the carb - nothing changed.
I'll check the dash switch - not sure if this all could be related to the drop in voltage to 8vdc on test points after the circuit breaker?
 

BuddyB77

Cadet
Joined
May 22, 2020
Messages
9
UPDATE
Still lots of crank but no start. After checking I have no spark.
I have 12vdc at the battery, the circuit breaker and the alternator. Everywhere else its 7.5-8vdc - the starter, carb, solenoid, etc.
Would it be safe to say that the voltage drop would be the cause of the problems?
Could corrosion around the connections cause the voltage to be lower?
I don't really understand what would cause the drop from 12 to 8vdc, can anyone help with this?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Run a wire from the battery positive to the coil positive and see if it starts. If it does, you'll need to pull the wire off to stop it.

If that solves the problem, you'll need to track down the bad connection. I'd start at the ends of the glass 20A fuse behind the dash.

Chris.....
 

jimbo_jwc

Ship Happens
Joined
Dec 19, 2010
Messages
633
I've had a few of these engines and currently running 2 still my routine every year is this ,clean the points with fine emery cloth and pull paper thru to clean .Check distributer cap and if coated scrape with pocket knife and clean .While cap is off turn ignition on open points w/screwdriver or short together to see if it sparks could be points not closing.There is a neutral safety micro or shift interrupt on top .Fill carburetor float bowl w/gas ,the elongated slot near center stud ,you might have to do once or twice.I use gear oil container and keep in boat at all times . This will save you in starter repairs from excessive cranking . I have rebuilt a few of the carbs and yes paint the linkage arms or take a picture of ,some kits I got had different accelerator pump rods .Only had a couple that needed fuel pumps rebuilt. The hardest one I ever had was from a boat that sat for years and the anti siphon valve in the tank gummed up restricted fuel flow and always was starved for fuel and this check value actually prevents fuel flow in that direction and is opened buy the pulsations from mechanical fuel pump .It's rating is probably less than !# .Good luck and happy boating ,part of the passion for boating is working on them ha-ha ..
 
Last edited:

BuddyB77

Cadet
Joined
May 22, 2020
Messages
9
UPDATE
First checked the ignition (key) switch as suggested - I've got a 10v fuse that tested good and I've got 11.5vdc on both sides of the switch - I am correct that it is safe to assume that is not the problem?

ACHRIS - I ran a jumper wire from the battery to the +12 on the coil which gave me the correct voltage at the starter and the coil but still no start.
While doing that a put the spark plug tester on and no spark
Still no fuel at all pumping through the fuel tube - it was a little bit gummed up so I cleaned it, no change.
After I removed the jumper wire I think I found where the voltage is dropping - Ive got 12vdc going into the starter and 8vdc coming out of it to the other components

So I know what is wrong but don't know the source of the problem since multiple issues
1. Drop in voltage coming out of the starter
2. No spark
3. No fuel pumping
If the starter was bad would it cause all of those issues?

What I haven't checked is the distributor, wires and spark plugs - there is a bit of corrosion around the spark plug holes in the block and had to clean some gunk off the plug but don't see any other issues.

Getting kind of frustrated but also learning more about the engine, thanks for helping!!
 

nola mike

Vice Admiral
Joined
Apr 22, 2009
Messages
5,023
UPDATE

So I know what is wrong but don't know the source of the problem since multiple issues
1. Drop in voltage coming out of the starter
2. No spark
3. No fuel pumping
If the starter was bad would it cause all of those issues?

1. Which other components are you talking about? Where measured? Your starter doesn't supply your coil voltage (except while cranking). Regardless, jumping directly to the coil from battery would eliminate wiring to the coil as the sole cause of your problems. I'd skip this for now.
2. Yeah, that's the problem.
3. Are you looking at the clear (probably yellow now) hose coming from the fuel pump to the carb? That's an overflow hose if the diaphragm on the fuel pump ruptures. Not normally any gas in there. Your fuel line is solid entering the carb. Pouring a little gas down the carb throat should at least get it to kick.
4. No.

Did you clean/check/set the points? That is where I'd start, concentrate on, and finish before moving on to something else. You can check everything up to the points by disconnecting wires from the coil (-) and attaching a jumper wire. Disconnect the center lead from the rotor and connect to a spark plug tester (or a grounded spark plug). With the ignition on (and your 12v jumper to the (+) in place), ground your jumper from the coil (-). When you remove it from ground, you should get spark. If so, that's points or a shorted tach as your problem. If not, that's your coil...

EDIT: Multiple other ways to do this as well. Check the stickies. Basically, you want to see if the points are making good contact when they close. They are providing a path to ground when they close, and interrupt that path when they open.
 

BuddyB77

Cadet
Joined
May 22, 2020
Messages
9
Hi Nola Mike
The other components are that I measured 8vdc at the carborator and switches - when I take the jumper wire off the voltage at the coil drops down to 8vdc as well. That is where I realized that I had 12v going into the starter and 8v coming out - I don't know if that means the starter is bad?

POINTS - This is where my lack of knowledge comes into play - can you explain "clean/check/set the points" for a novice?
Does that mean remove the plug wires and check all of the connections are tight? How do I clean them?
Greatly appreciate the info!
 

Scott06

Vice Admiral
Joined
Apr 20, 2014
Messages
5,543
A picture is worth 10 k words ....google how to clean and adjust points plenty of YouTube videos. You’ll need a dwell meter and timing light so you can set timing while you are there.
 

nola mike

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