3.0 Hard Starting

Shadow66 · Jun 29, 2009

Have a 2002 Mercruiser Alpha 1 Gen 2, 3.0L Carb

OK, so the carb was cleaned twice, all filters and fuel pump replaced (dealing with other issues) and a full tune up was given.

It is running like a champ now when started (4,800 RPM's easy and no hesitation). But when stopped for more than a few seconds I have to crank it for 15, 20, or 30 seconds to get it to catch and fire up. Funny thing is: it starts easiest first start of the day...not all the time, but most of the time.

I have tried priming it with 3, 4, 5, 6, and even 7 pumps before starting and this does not seem to have any effect.

When I asked the dealer he said that he has heard this from many 3.0 carb owners that they are having issues with starting.

Any tips would be helpful. Should it not start right away after the first start? I know now it will most likely start for me. But I own a 2007 truck which starts every time the first time and have not had a carbed motor for over a decade. So it is unnerving not being absolutely certain it will start out in the middle of nowhere in some section of the ICW.

Thanks!

Schmoe · Jun 29, 2009

Re: 3.0 Hard Starting

Check to see where the butterfly valve position is at when starting. You may not be getting enough choke, or too much. Sounds like it's somewhere within the fuel delivery system or it could be a bad ignition switch.

danond · Jun 29, 2009

Re: 3.0 Hard Starting

When you say the carb was "cleaned" twice, was it ever rebuilt? Cleaning a carb doesn't do much for the parts that actually get clogged up or broken, and doesn't involve adjusting your float, etc.

Sounds like it is flooding when there's pressure in the fuel system. Leaking needle/seat can do that. Only fixed with a rebuild.

Run it 'till warm, shut down, take the flame arrestor off, then look down the carb throat. See fuel dripping into the engine?

Rocky_Road · Jun 29, 2009

Re: 3.0 Hard Starting

Shadow66 said:
When I asked the dealer he said that he has heard this from many 3.0 carb owners that they are having issues with starting.

I think that your answer lies in your dealer's observation...that many of us 3.0L owners have this problem.

My current copy of BOATING MAGAZINE (July/August 2009) has an article about ethanol fuel, and says this:

"...many boat engines lack the electronic controls needed to compensate for these ethanol blends, which are rich in oxygen and can allow the engines to run too lean, causing misfires and a loss of power. These engines are also hard to restart when hot."

Our 3.0L's are carbed, and do not have engine computers to compensate for the fuel blends we use. My engine has less than 45 hours on it...is in perfect health...starts with just a 'bump' of the starter when cold...and can be a pain to restart when hot. The one time that I bought marina gas (non ethanol), she didn't have any restart issues.

Be careful about throwing money at a problem, that cannot be 'fixed'!

Shadow66 · Jun 30, 2009

Re: 3.0 Hard Starting

Ya know, the choke did come to mind to me yesterday and will need to check on that next time.

Yes it was completely rebuilt the first time about a month ago. Then I changed the fuel pump (which was missing the filter in it and the filter bowl was rusting from the inside) and cleaned the carb filter. Apparently some of this rust got into a jet again and he had to remove it and clean it again. But I will check for any leaking fuel like you suggested, thanks for the tip.

Now the thing about the ethanol...funny I started a thread about Ethanol before on this site and it was shut down almost immediately. Lots here do not think this can be any issue even though my dealer and millions of others believe it is. I put non ethanol fuel in my boat yeserday and will run it next weekend and see about this starting issue. Did the article suggest any compensation adjustments for the carbs of these 3.0L considering the ethanol blend? Of course it has been in our gas since the 1600's

according to some here.

Bt Doctur · Jun 30, 2009

Re: 3.0 Hard Starting

http://www.mercurymarine.com/serviceandwarranty/mercruiserfaqs/ethanol.php#top

Shadow66 · Jun 30, 2009

Re: 3.0 Hard Starting

Yup, I've seen this article from Mercury marine a thousand times and it says nothing about my hard starting issue.

How about it Rocky?

Rocky_Road · Jun 30, 2009

Re: 3.0 Hard Starting

Shadow66 said:
I put non ethanol fuel in my boat yeserday and will run it next weekend and see about this starting issue. Did the article suggest any compensation adjustments for the carbs of these 3.0L considering the ethanol blend? Of course it has been in our gas since the 1600's according to some here.

Where did you find 'real' gas? Here in Florida, even the marinas have to sell E-10, as of late....

No...I have never seen any 'hints' on dealing with ethanol, in an engine that is not computer controlled. Any adjustment to aid hot starting, would probably do the opposite for your cold starting. As it stands now, I would rather have my engine start easily at the launch ramp...!

I'm going on a mission to learn all that I can about our problem. If I get anywhere...I'll post the findings!

Happy boating!

Shadow66 · Jul 1, 2009

Re: 3.0 Hard Starting

Thanks Rocky. I found the gas at an Exxon here on Savannah Highway in Charleston. He is selling the mid grade with 0% ethanol and being promoted by all the major marinas and dealers in the area. I filled up two days ago.

Bilgamesh · Jul 1, 2009

Re: 3.0 Hard Starting

My '98 3.0L is hard to start when warm too. By hard to start, I mean that I have to give it throttle to start, then back it off into neutral to engage the outdrive. Is this what you mean by hard to start, or do you mean it is hard to start with or without throttle? I am curious to know if I am chasing a phantom carb problem, and I should instead start looking for gas with little or no ethanol.

FWIW: http://articles.latimes.com/2008/apr/15/business/fi-boat15

- Thanks

Rocky_Road · Jul 1, 2009

Re: 3.0 Hard Starting

Bilgamesh said:
My '98 3.0L is hard to start when warm too. By hard to start, I mean that I have to give it throttle to start, then back it off into neutral to engage the outdrive. Is this what you mean by hard to start, or do you mean it is hard to start with or without throttle? I am curious to know if I am chasing a phantom carb problem, and I should instead start looking for gas with little or no ethanol.

FWIW: http://articles.latimes.com/2008/apr/15/business/fi-boat15

- Thanks

Read this BEFORE you start tearing your engine, and carb, apart:

"ETHANOL AND VAPOR LOCK

Short description:
When the engine compartment becomes hot either by climate or idling, and you use ethanol-blend gasoline it can cause excessive vapors in your fuel line and starve the engine of fuel. The engine can run poorly or stop and will not run until the fuel condenses.

THE PROBLEMS

Vapor Lock

Fuel containing 10% ethanol is called E10. If you have ethanol in your gas, you run the risk of creating vapor lock because of excess vapors.

Ethanol ?boils? at 87?F (at normal atmospheric pressure) and turns from a liquid to a gaseous state. By comparison, most automobiles have their fuel pump in the gas tank, so the whole system remains under pressure unlike boats whose fuel tanks are vented. In a closed system, the higher pressure raises the flash point of the ethanol reducing the amount of vapor that is produced. In addition, most automobile fuel lines are outside of the vehicle allowing them to stay cooler.

Since most boat fuel lines are in the enclosed space (sometimes even insulated) of the engine compartment, normal ventilation will not cool the fuel significantly enough to avoid the potential problems of vapor lock. Furthermore, since the fuel pump in a boat is mounted on the engine (versus a car where the pump resides in the tank) the action of the pump can reduce pressure in the tank to below atmospheric pressure and further reduce the flash point.

Boat engineers are aware of this problem and are reducing the likelihood of this occurring by reducing the suction required by the fuel pump, minimizing hose fittings and bends, and including a quality anti-siphon valve. In existing boats, fuel lines and filters should be kept as low in the boat as possible and tank vents should be cleaned and open.

Heat Soak

Most boats have ?forced? ventilation. Air moves through the engine compartment when the boat moves forward. Heat soak happens after you have been at high RPM and then stop or drift on idle for a while. Because of heat soak the engine compartment will rise to a point where the ethanol will boil

THE CURE

To prevent vapor lock (i.e. boiling ethanol):

Make sure the engine compartment has adequate ventilation.
Relocate fuel lines to be low in the bilge. (The bilge is cooler because it is in direct contact with the water.)
Monitor the engine compartment temperature.
Add (or turn on) engine room blowers.
Keep the tank vent clean and unobstructed.

http://www.marinepartsexpress.com/express/express_3_1.htm

Bilgamesh · Jul 1, 2009

Re: 3.0 Hard Starting

I'm hoping to drive just out of the county and put in some ethanol free gas to see if there is anything to this. Otherwise it sounds like I am left to wrapping the fuel lines with some kind of heat shielding material.

elkhunter338 · Jul 1, 2009

Re: 3.0 Hard Starting

my 3.0 with 35 hours on it 2008 motor with carb off the 1971 orginal engine runs fine after I leaned out the jets. She was running too rich with the 50/51 jets that came with the rebuilt carb. I think I am running a 49/48 forgot for sure might be a 48/46. Anyway let the engine cool down at idle for 3 min or so before you shut it down, while you are doing that run the blower motor to remove some heat from the engine compartment.
Mine starts ok if I do this, but mine also start better cold in the morning. Always has even with the old motor.

Bilgamesh · Jul 2, 2009

Re: 3.0 Hard Starting

Shadow66, please share the outcome of trying the new gas with us. Hopefully before July 4th!

Shadow66 · Jul 4, 2009

Re: 3.0 Hard Starting

Bilgamesh said:
Shadow66, please share the outcome of trying the new gas with us. Hopefully before July 4th!

Sorry, not going to run it until Sunday. The 4th is mayhem here with all the drunk kids out...

Bilgamesh · Jul 4, 2009

Re: 3.0 Hard Starting

Hopefullly this will not be perceived as a hi-jack of the thread. I share it hoping that something here may resonate with your problem. Motor runs well, and starts right up when cold. If I try to start immediately after shut-off, it starts right up. If I wait more than a few seconds, it is hard to start, and I have to use throttle.

I tried to find E0 fuel in my area, with no luck. Instead I used a premium grade with no help for my problem. I tried wrapping my fuel lines, to alleviate heat, also with no luck. I tried adjusting my choke to no effect. However, I think I found my problem. I pulled the flame arrestor and noticed fuel continued to drip from the venturi. From many similar posts on the forum, it seems like I may need to rebuild the carb to replace a leaky needle and seat. Still researching, but closer to solution I think. - Thanks

Shadow66 · Jul 6, 2009

Re: 3.0 Hard Starting

OK, took it out yesterday. I could not get up above 3,000 RPM's because of wave chop so I still have more experimenting to do. I only went through 4 gallons of gas.

The overheating/evaporation ethanol problem seems like the key. The new gas allowed me to let it sit for a few hours and then start right up. It was a very hot day (90) but overcast. I did open the compartment 2 times to let it air out.

It started right up with no cranking. I will need a real hot day to test this again and since today seems like a washout I will not be able to until next weekend. (Why the hell does every Monday rain here?

).

So far, the new ethanol free gas seems like a hit. By the way, when I went to that gas station with the ethanol free gas yesterday there were huge boats and a yacht filling up with it. I asked one guy if it is making a difference for him. He just looked at me and said "No stalling, no sputtering, no sh*t. I'd call that a difference."

He has been using it now for 2 months. He said he had it in the shop 4 times for fuel related starting/stalling issues and not since.

Just a few opinions I'm passing on.

Bilgamesh · Jul 7, 2009

Re: 3.0 Hard Starting

Shadow66, my motor was acting much like yours, except I could give it throttle to start it up. I found the carb was dripping fuel after shutdown and flooding the engine, as mentioned by "dandond". Giving it throttle introduced enough additional air to allow it to start. I rebuilt my carb yesterday, and cleared my problem entirely. Hopefully you have found yours with the ethanol thing, but if not, it might be beneficial to revisit the carb troubleshooting.

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