Author Topic: Mercruiser 140 difficult to start when cold [FINALLY, SOLVED!] (Read 49204 times)

75starflight · « **Reply #20 on:** June 25, 2015, 03:44:31 PM »

Eric, the top of the carb is really easy to take off on the 140. I think it is just 4 screws to remove the top cover and then you can access the fuel bowl, float, and the pump. I had my carb rebuilt by the carb shop in St. Paul, MN. It was very reasonable.

http://www.thecarburetorshopus.com/contact-the-carburetor-shop-saint-paul-mn.htm

Neutron68 · « **Reply #21 on:** June 25, 2015, 08:09:09 PM »

I'm afraid of losing little screws, springs, or levers while taking apart something I'm not familiar with.

The boat is hovering over the lake on the boat lift for the summer, so any work will have to get done there, or out on the lake itself.

Rosscoe · « **Reply #22 on:** June 25, 2015, 09:32:31 PM »

Quote from: 75starflight on June 25, 2015, 03:44:31 PM

Eric, the top of the carb is really easy to take off on the 140. I think it is just 4 screws to remove the top cover and then you can access the fuel bowl, float, and the pump. I had my carb rebuilt by the carb shop in St. Paul, MN. It was very reasonable.

http://www.thecarburetorshopus.com/contact-the-carburetor-shop-saint-paul-mn.htm

I've had at least 2 carbs rebuilt there. For the most part, its one guy with carbs stacked to the ceiling and although he is busy, he takes time to explain things.

Glastronjohn18 · « **Reply #23 on:** June 25, 2015, 11:06:32 PM »

Quote

1. engine seems starved for fuel when trying to start (accelerator pump?)
2. engine nearly dies if you punch the throttle (accelerator pump?)
3. engine does NOT die if you accelerate slowly
4. once engine is running it stays running (main fuel pump ok?)
5. engine doesn't run smoothly below 1000 RPM
6. engine runs fine at high RPM (main fuel pump ok?)

Once you slowly work into the main fuel circuit the idle circuit is no longer active and the engine runs fine. These all sound like idle circuit lean fuel conditions.
Going back to your previous post you said the boat was winterized and sta-bil put in the fuel. Now the question is was the motor run for 5-10 minutes to get the sta-bil to the carb.
At high RPM the motor runs fine. This tells me you're getting enough fuel eliminating fuel pump issues.

I'd start by opening the top of the carb and see if there is any debris or gunk in the fuel bowl. Then spraying carb cleaner in every orifice you can find.
You can find repair manuals or carb rebuilding instructions on line. You tube has many carb subjects. You don't need to rebuild the carb just get a feel for how its put together.

Try this video you can see what it takes to get the top off.

https://www.youtube.com/watch?v=fm9pxRFPth4

You can do this. Good Luck.

Just my 2 cents.

Plugcheck · « **Reply #24 on:** June 25, 2015, 11:38:23 PM »

Your list of symptoms is nearly identical to the carb issues that plagued Doren last year. Since the boat is on the water, pull the carb and make it right off the engine. You had stabik in the fuel tank, but I wonder if it got a chance to circulate through the carb. Really sounds like accel pump circuit, and idle circuit issues.

dorelse · « **Reply #25 on:** June 26, 2015, 10:55:12 AM »

Quote from: Plugcheck on June 25, 2015, 11:38:23 PM

Your list of symptoms is nearly identical to the carb issues that plagued Doren last year. Since the boat is on the water, pull the carb and make it right off the engine. You had stabik in the fuel tank, but I wonder if it got a chance to circulate through the carb. Really sounds like accel pump circuit, and idle circuit issues.

And, that I still have...lol! However, I can punch mine and I have the 1/2 sec gasp, and then the boat will take off. Its not the worst issue I could have so I'm going to live with it for now. Lots of other things to do this summer. I do know that its in the carb since your carb Mike, completely eliminated the issue.

Neutron68 · « **Reply #26 on:** June 27, 2015, 06:06:09 PM »

It is good to know that dorelse has the same symptoms, and he was able to cure them by a carb swap. That gives me hope this may not a too terrible of a problem.

I just got up to the lake. I'll watch that video and then try and look in my carb and see what I can see.

Eric

MikeB · « **Reply #27 on:** June 27, 2015, 06:17:20 PM »

+1 for the Carb Shop in St. Paul. I had similar issues with my 305 and now everything is running perfectly.

Neutron68 · « **Reply #28 on:** June 28, 2015, 10:35:16 AM »

Quote from: dorelse on June 26, 2015, 10:55:12 AM

And, that I still have...lol! However, I can punch mine and I have the 1/2 sec gasp, and then the boat will take off. Its not the worst issue I could have so I'm going to live with it for now. Lots of other things to do this summer. I do know that its in the carb since your carb Mike, completely eliminated the issue.

dorelse, do you also have the difficult starting problem?

If so, how do you work around it? 20 pumps of the throttle lever?

Neutron68 · « **Reply #29 on:** June 28, 2015, 12:29:25 PM »

I just got my neighbor to pump the throttle lever for me while I held the choke open and watched inside the carburetor throat.

I saw NO squirts of gas inside the carburetor throat, whatsoever!

I have not looked at the carb fuel filter yet...after lunch.

thedeuceman · « **Reply #30 on:** June 28, 2015, 01:15:23 PM »

I think there should be a check valve in there, small ball bearing under the Excelerator pump. Maybe the guy that rebuild the carb lost it. If that's missing when the Excelerator pump pushes down the gas Will just go back into the bowl

75starflight · « **Reply #31 on:** June 28, 2015, 02:03:19 PM »

Quote from: Neutron68 on June 28, 2015, 12:29:25 PM

I just got my neighbor to pump the throttle lever for me while I held the choke open and watched inside the carburetor throat.

I saw NO squirts of gas inside the carburetor throat, whatsoever!

I have not looked at the carb fuel filter yet...after lunch.

Looks like you found your problem! If the filter in the carb isn't plugged pull the top off and take a look inside or pull the carb and take it to the carb shop. Either way you aren't going to hurt anything at this point.

Neutron68 · « **Reply #32 on:** June 28, 2015, 03:34:34 PM »

The carb fuel filter isn't plugged but it's not pristine clean, either.
SEE:
http://i870.photobucket.com/albums/ab264/neutron68/Glastron/20150628_141416_zpsdhzjr5i1.jpg

http://i870.photobucket.com/albums/ab264/neutron68/Glastron/20150628_141412_zpstak5fb3e.jpg

This carburetor (part 7040084, date code 211 1 1) has 8 screws securing the top.
http://i870.photobucket.com/albums/ab264/neutron68/Glastron/20150628_140629_zpshbmccqhk.jpg

Neutron68 · « **Reply #33 on:** June 29, 2015, 09:13:42 AM »

I just talked to Greg, the guy who replaced the engine. He said he definitely replaced all the parts in the carb kit, including the accelerator pump. He said he tested it on his bench and again by running the engine.
His best guess was that something had come disconnected.
He said he'd fix it if I wanted to bring it back to him, but he's booked right now with work promised for July 4th.
For me taking the boat back to him would be a whole day of logistics (pay neighbor to pull the boat out of lake and onto the trailer, drive 75 miles to him, wait, drive 75 miles back, put the boat back in the lake.)

I now plan to take the top off and see if I can fix it here.
Greg said I shouldn't need to buy any parts as long as I don't tear the gasket.

I've not taken the top off the carb yet. I'm concerned about the linkages and losing a clip or screw.

Plugcheck · « **Reply #34 on:** June 29, 2015, 10:57:02 AM »

Pull the carb, hard to say which is worse, dropping small parts into the intake or into the bilge. Fuel line, linkage, and four nuts and its off. Gaskets should be pliable enough yet to have not stuck.

Jason · « **Reply #35 on:** June 29, 2015, 12:02:37 PM »

you could disconnect the fuel line at the carb, crank then engine, see if any fuel squirts out the fuel line. At least you know fuel is getting to the carb. The carb is easy to remove. I did a carb swap on the river once. Takes about 15min. Also don't be afraid to open the carb up. It's a super simple design.

dorelse · « **Reply #36 on:** June 29, 2015, 01:25:01 PM »

I still have the accelerator pump issue, but mine always starts in 1/2 a turn. Cold/warm, doesn't matter.

Sent from my HTCONE using Tapatalk

Neutron68 · « **Reply #37 on:** June 29, 2015, 02:51:45 PM »

Given my symptoms of the engine being hard to start after a week of sitting, but starting fine the rest of the day, after that first start, the suggestion that gas is leaking out of the carb bowl over time fits.

Given that there isn't gas running all over the engine and bilge area, I'm going to venture that the it's running back down the fuel line to the gas tank?

Does a correctly functioning accelerator pump normally keep gas from flowing back down the fuel line to the tank?
Or does that role fall solely on the "check-valve" ball bearings?

Plugcheck · « **Reply #38 on:** June 29, 2015, 04:16:36 PM »

Fuel cannot siphon back down the supply line, nor down the throat of the carb unless the well is broken. The accelerator pump circuit may drip fuel under high vacuum conditions, but the discharge nozzles are generally not large enough to produce the venturi effect. Your carb needs attention, get to someone who knows carbs well. Had you sent it when I offered to fix it for you, you would be on the water now.

Neutron68 · « **Reply #39 on:** June 29, 2015, 04:47:34 PM »

Quote from: Plugcheck on June 29, 2015, 04:16:36 PM

Had you sent it when I offered to fix it for you, you would be on the water now.

I appreciated your offer, but the boat resides on a boat lift 85 miles away from my fulltime home. I was simply not able to get my hands on it until Saturday afternoon. And, I would not have been able to mail it until today (Monday) as the post office closes around noon on Saturdays and is not open on Sundays. So, it just wasn't logistically possible in such a short time frame.

Eric