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Kalamykid
Kalamykid, Shop owner/ Tech.
Category: Car
Satisfied Customers: 4450
Experience:  I HAVE OWNED MY OWN SHOP FOR OVER THREE YEARS. I HAVE THE TOOLS AND SOFTWARE TO ANSWERE ALMOST ANY Q
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Story, I'll try to make short. Bought a project boat last

Customer Question

Long story, I'll try to make short. Bought a project boat last year, gutted and restored the deck and interior. Motor is a 1986 Mercury 140 3.0. Replaced the starter, carburetor, head gasket, plugs and wires. Started it up two days ago, ran great, took it to the lake for the first time. Ran fine, pulled the kids on a tube, everything seemed fine. Started noticing a hesitation when I accelerated and then it would run fine. Evening comes, head back to the dock. Kids want to swim so I stop a few hundred yards away. Go to leave, engines cranks and cranks but won't fire. Finally starts running just enough to limp within 30 feet of the dock and dies, have to paddle back in. Get it home and start to check everything out. It has fuel, streams shoot out the carb when it is throttled. It has compression, 150 or close on all 4 cylinders. It has spark but it looked a bit weak. Replaced the coil. Replaced distributor cap, rotor and points. Still won't fire. Put starter fluid straight in the plug holes, still nothing. Pull a plug to test spark again and the engine fires and runs, runs rough but it runs. I can pull out any plug and leave it attached to the wire, or not, the engine will run. Put all 4 in and it won't start. Pulled out the distributor, doesn't seem damaged. Pulled the timing cover and the gears appear to be lined up. I'm stuck.
Submitted: 1 month ago.
Category: Car
Expert:  Kalamykid replied 1 month ago.

When you did the compression test, did you have all the plugs out?

Customer: replied 1 month ago.
I believe so. I've messed with it so much I honestly can't remember.
Expert:  Kalamykid replied 1 month ago.

Can you redo the compression test, but this time remove all the plugs?

Customer: replied 1 month ago.
I'm at work now. Can I do it tomorrow and contact you after? Also I replaced the head gasket before this happened, you thinking it might have blown again?
Expert:  Kalamykid replied 1 month ago.

Yes you can come back to this chat screen for as long as we need to be able to solve this problem. It is possible that it has. The compression test will tell us more.

Customer: replied 1 month ago.
OK, talk to you tomorrow, after I check the compression, thanks.
Expert:  Kalamykid replied 1 month ago.

Chat with you tomorrow.

Customer: replied 1 month ago.
OK, checked them this morning with all the plugs out. Cylinder 1 = 151 2= 149 3 = 130 4 = 138
Decent drop on 3 but that should still fire shouldn't it?
Expert:  Kalamykid replied 1 month ago.

There would be a good miss, but it should run unless there is a bad valve. Did you have a valve job done on the head when you had it off?

Customer: replied 1 month ago.
No I just replaced the gasket and put the head back on. But it was running great afterwards until it just died.
Expert:  Kalamykid replied 1 month ago.

Can you send me a pic of the engine please so I can see what engine you have?

Customer: replied 1 month ago.
Here are some pics of the engine and the data plate. Ofcourse the plugs and wires are out and the fuel line to the carb is off. Took it off to remove the valve cover and make sure the valves were all moving.
Expert:  Kalamykid replied 1 month ago.

Can you get one of the valve train with out the valve cover on?

Customer: replied 1 month ago.
On the road now, I'll have to take it tonight.
Expert:  Kalamykid replied 1 month ago.

Thank you. Chat with you tonight.

Customer: replied 1 month ago.
Pic with valve cover off.
Expert:  Kalamykid replied 1 month ago.

Can you back all the rockers off two full turns and redo the comp test p!ease?

Customer: replied 1 month ago.
At work now. I'll be home tomorrow until 3PM central. Would it be better to start tomorrow morning and just give you a call or does the chat work better for you?
Expert:  Kalamykid replied 1 month ago.

If you want a phone call, that is ok with me. If I am right, the valves are just to tight and need to be readjusted.

Customer: replied 1 month ago.
hope you're right. I'll give it a try tomorrow.
Expert:  Kalamykid replied 1 month ago.

Do just the comp test please and let's see what it tells us.

Customer: replied 1 month ago.
Cylinder 1 = 130 2= 130 3= 130 4= 100 Checked #4 three times got 100 each time
Customer: replied 1 month ago.
I noticed the intake on #4 was a lot looser than the rest. I tightened it up a full turn and rechecked the compression and got 130
Expert:  Kalamykid replied 1 month ago.

Then you need to readjust all of them and let's see if we can got 150 on each of them. Here us the best way to adjust them.

Expert:  Kalamykid replied 1 month ago.

Turn the crank so both valves are closed on the cylinder you are adjusting. Back so the rockers off three full turns. With o email hand roll the push rod back and forth, slowly tighten the rocker back up till the push rod just stops turning. Then turn the nut 1\2 turn more and go to the next rocker. Make sure the valve is closed that you are doing. Then recheck all the cylinders again and let's see what you get.

Customer: replied 1 month ago.
Just so I get this right. I think you got some typos here.
Back so the rockers off three full turns. With o email hand roll the push rod back and forth, slowly tighten the rocker back up till the push rod just stops turning.
Expert:  Kalamykid replied 1 month ago.

Sorry. I am using !y tablet and the dang auto correct messes me up. With one hand roll the push rod.

Customer: replied 1 month ago.
got it thanks
Expert:  Kalamykid replied 1 month ago.

You are welcome.

Customer: replied 1 month ago.
150. 142. 142. 135.
Expert:  Kalamykid replied 1 month ago.

Sorry for the delay, I am trying to get an engine in myself. The numbers came up like I hoped, but ,,4 is still to low. I hate to say it, but go back over cylinder 4 valves and readjust them one more time and see if it will come up a little bit more. It is close, but I would like to see it up to at least 140.

Customer: replied 1 month ago.
Finally got back to it today. I had to play with it a bit but cylinder 4 is reading 140 now. If I tighten it just a quarter turn more though it won't even give me a reading on the compression gauge.
Expert:  Kalamykid replied 1 month ago.

Have you tried to run it at all? It should be good to go now.

Customer: replied 1 month ago.
I tried it this morning and it didn't start but the battery is pretty low from the compression tests. I'm going to charge it all day and try after work tonight or tomorrow morning.
Expert:  Kalamykid replied 1 month ago.

Let me know what it does.

Customer: replied 1 month ago.
Been working too much, finally got back to it today. Still won't start, sounds the same as before. I'm sure you know more about this than me but it was running great and then just wouldn't start anymore. How would the valves have that effect on it? Could they have come loose that quickly. Seems to me something must have broke or come loose or something for it to just stop running. What am I missing?
Expert:  Kalamykid replied 1 month ago.

Do you have some carb cleaner?

Customer: replied 1 month ago.
Expert:  Kalamykid replied 1 month ago.

Remove the air cleaner and spray a good amount into the carb and see if it will start.

Customer: replied 1 month ago.
Tried it. Still won't start. It's a brand new (rebuilt) Carb. I just bought it and put it on before taking it on the water. Plus if it wasn't getting any fuel why would it run on 3 cylinders?
Expert:  Kalamykid replied 1 month ago.

Do you have spark on all 4 cylinders? Can you try to start it again, then pull, the plugs and send me a pic of them so I can see the tips?