Mercruiser 3.0 takes long time to start...

[cheejudo]

MY mercruiser takes a bit to start.. last weekend it took bout 10 minutes of off and on crankin to get it going.. not sure what the problem is

 

[Don S]

Re: Mercruiser 3.0 takes long time to start...

Is this boat new to you? Do you use the throttle only position of the control to pump the throttle and give it some throttle while cranking?

 

[cheejudo]

Re: Mercruiser 3.0 takes long time to start...

Yes I've tried the throttle only

 

[Don S]

Re: Mercruiser 3.0 takes long time to start...

When cold, is the choke fully closed?

Remove the flame arrestor and disconnect the throttle cable from the carb linkage, open the choke manually and operate the throttle linkage and see if the accelerator pump is squirting fuel into the throttle bores.

 

[cheejudo]

Re: Mercruiser 3.0 takes long time to start...

Are we talking cold starts or all the time?

Cold starts ONLY. Once I get her off the trailer and running around the lake for a few minutes she will start right up.





Don S - Can I do this without trying to start the boat? Im not near a lake right now.

 

[Don S]

Re: Mercruiser 3.0 takes long time to start...

Don S - Can I do this without trying to start the boat? Im not near a lake right now.

Yes if you are referring to this:

Remove the flame arrestor and disconnect the throttle cable from the carb linkage, open the choke manually and operate the throttle linkage and see if the accelerator pump is squirting fuel into the throttle bores.

You don't have to even turn the engine over, just move the carbs throttle linkage and watch down the throttle bores.

 

[Don S]

Re: Mercruiser 3.0 takes long time to start...

Don S - Can I do this without trying to start the boat? Im not near a lake right now.

Don't you know how to run your engine on muffs (aka a flusher)?

I am beginning to think the only problem is your starting method. Especially if you have never operated an engine with a carb before.
They DO NOT start like your EFI car. It takes a bit of getting used to.
You start by putting your shifter into the throttle only mode, then pump the throttle to full throttle at least one time. Do not pull it all the way back to neutral, or you will have to put it into throttle only mode again.
Once you pump the throttle once or twice (time and trial and error will tell which is best) put the lever at 1/4 to 1/2 throttle and crank the engine. Don't let it over-rev, pull it back as needed to keep the rpm around 1200 to 1500 rpm until it warms up enough to idle on its own.

 

[cheejudo]

Re: Mercruiser 3.0 takes long time to start...

Don't you know how to run your engine on muffs (aka a flusher)?

I am beginning to think the only problem is your starting method. Especially if you have never operated an engine with a carb before.
They DO NOT start like your EFI car. It takes a bit of getting used to.
You start by putting your shifter into the throttle only mode, then pump the throttle to full throttle at least one time. Do not pull it all the way back to neutral, or you will have to put it into throttle only mode again.
Once you pump the throttle once or twice (time and trial and error will tell which is best) put the lever at 1/4 to 1/2 throttle and crank the engine. Don't let it over-rev, pull it back as needed to keep the rpm around 1200 to 1500 rpm until it warms up enough to idle on its own.

Yes I know how to use muffs; no i don't have a set.

I understand that my boat is not efi. I have tried this method you have explained, thus why I am here.

 

[Don S]

Re: Mercruiser 3.0 takes long time to start...

Yes I know how to use muffs; no i don't have a set.

I understand that my boat is not efi. I have tried this method you have explained, thus why I am here.

Great, that's the kind of stuff we didn't know at the beginning of this thread. But that starting info has helped many in the past.
You need to check your accelerator pump.
When was the last full tuneup? Cap, rotor, spark plugs, etc.?

 

[cheejudo]

Re: Mercruiser 3.0 takes long time to start...

edited

 

[cheejudo]

Re: Mercruiser 3.0 takes long time to start...

I had a tune up on it when i bought it last year. Unfortunately the boat didnt come with a manual so I am not sure where the accelerator is

 

[Don S]

Re: Mercruiser 3.0 takes long time to start...

The "accelerator pump" is parts inside the carb. All you can do is check to see if it works. By watching inside the carb and opening the carb linkage to wide open throttle (WOT) and seeing if gas squirts into the carb. If it doesn't, then something is wrong in the carb. If it does squirt, then we look for something else.

 

[cheejudo]

Re: Mercruiser 3.0 takes long time to start...

First of all, thanks to everyone for the fast responses.


I took a video of my carb.. I am pretty clueless right now about engines so I am hoping it will help me help you identify the problem..

The gold plate i am opening... is this the choke butterfly?? The only way i can figure out how to open and close it is with my fingers. I pushed the throttle foward and saw gas.. but i dont know if i have one of those things that the car in the video had.. im lost! lol


http://youtu.be/fN7jAuiltPA

 

[Harritwo]

Re: Mercruiser 3.0 takes long time to start...

Yes, you are opening the choke plate. When you advance the throttle, you should see a shot of gas going into the carb while the throttle is being opened.

 

[ktbarrentine]

Re: Mercruiser 3.0 takes long time to start...

I had a tune up on it when i bought it last year. Unfortunately the boat didnt come with a manual so I am not sure where the accelerator is

Love (and hate...haha) these carbs! I see you've been on here awhile (alot longer than me!), so you should know where the "adults only" section of the mercruiser forum is. There you will get all (well, alot, anyways) of the technical info/manuals, etc for your engine, drive, carb... I DL'd everything I could to a folder on my laptop for ready reference. Good video, by the way. should help... SOunds like you said you saw gas when the accelerator pump actuated. Should have seen (and heard...) two small streams of gas shooting right into the throttle body bores. ALso looks like your choke may be closing too far on cold start. Should be something like an 1/8" open. Your carb manual will guide you. I had to grunt my way through all these issues when I got my new (used) boat.... Good luck! It's boating season here!

 

[cheejudo]

Re: Mercruiser 3.0 takes long time to start...

So i made a second video.

I disconnected the throttle cable so i didnt have to have someone help. I think the first time i saw gas was a fluke, because now when i operate the throttle it appears that only air is being shot out. But the butterflies are opening and closing.


http://youtu.be/hyF4dm9JeNI

 

[Don S]

Re: Mercruiser 3.0 takes long time to start...

Have you run the engine since you have started checking for fuel? If not, you have probably pumped all the fuel out of the carb. Without the engine running the pump can't fill the carb back up.

 

[Silvertip]

Re: Mercruiser 3.0 takes long time to start...

The choke does appear to be set way too tight. On a stone cold engine it should just barely close -- not slam shut like yours does. As soon as the engine starts it should pull open a bit and then continue to open gradually as the choke heater warms. It should stand perferectly vertical when the engine is fully warmed up.

 

[Don S]

Re: Mercruiser 3.0 takes long time to start...

The choke does appear to be set way too tight.

I agree, if the choke is adjusted to the specs in the service manual, they are too tight and snap shut just like his does. If the vacuum break is adjusted properly, it will open the choke a bit due to engine vacuum once started. But unless you boat in very cold weather, the choke is too tight. It's also not part of your starting problem.

 

[cheejudo]

Re: Mercruiser 3.0 takes long time to start...

Well I think its safe to say the accelerator pump isn't the problem, being that my butterflie thingies open and close and fuel squirts out lol..

Whats nexT!