4.3 Mercruiser LX hard to start

[skeffington]

My 1994 Mercruiser Lx is very hard to start, especially cold. If it has been running very recently it will start right up but after sitting for just a few minutes it will take quite a bit of cranking to get it going. It sounds like it idles at a very slow speed, but it does idle fine and seems to run very good. Any suggestions? I assume i need to adjust the carb but I'm fairly new to carbs. Thanks

 

[achris]

Re: 4.3 Mercruiser LX hard to start

The Weber 9600 series carbies on those engines has a habit of dribbling after shutdown.... Meaning after a few minutes the engine is flooded, making it hard to start, or after a long shutdown (a few days) the carbie is empty and the fuel pump needs to fill it before it will fire, making it hard to start.... I have done exhaustive investigations on this problem, and the only way I was able to fix it was to replace the engine with an MPI (see my signature )...

Chris.......

 

[skeffington]

Re: 4.3 Mercruiser LX hard to start

Mine can take 30 seconds of cranking to fire after sitting for 10 minutes. I think it idles too low and without a choke or being able to start with some throttle it doesn't want to fire. Any suggestions or maybe I'm way off base. Thanks

 

[skeffington]

Re: 4.3 Mercruiser LX hard to start

After reading a bit more maybe my choke just isn't set right. I don't really understand how the choke works on these engines.

 

[81 Checkmate]

Re: 4.3 Mercruiser LX hard to start

Goggle how a choke works on your year carb engine.

It seams Chris has delt with the problem many times....... Maybe a different style carb is in odrer....

Not a carb guy, but i am sure others will chime in with their results

 

[achris]

Re: 4.3 Mercruiser LX hard to start

Mine can take 30 seconds of cranking to fire after sitting for 10 minutes. I think it idles too low and without a choke or being able to start with some throttle it doesn't want to fire. Any suggestions or maybe I'm way off base. Thanks

That is exactly the symptom.... Nothing to do with the idle speed or the choke... It's just a characteristic of the carb.... All I can suggest replacing the Weber with an Edelbrock 1409...

 

[skeffington]

Re: 4.3 Mercruiser LX hard to start

Alright thanks Chris. It's frustrating and I'm worried I'm either going to drain my battery or ruin my starter, but I guess there is nothing wrong. Thanks again.

 

[Don S]

Re: 4.3 Mercruiser LX hard to start

Do you use the throttle at all when starting, or just leaving it in neutral?

 

[ericjeeper]

Re: 4.3 Mercruiser LX hard to start

First we need to determine whether it is a lean starting issue, or a rich. I am guessing rich, since you say the idle is very low. If pulling it into neutral and giving it a little throttle helps. Try turning the idle screw in about an 1/8 to 1/4 of a turn. This will in turn open the throttle plate just a little.
If this does not help you might need to adjust the choke to close at a cooler temp.

 

[skeffington]

Re: 4.3 Mercruiser LX hard to start

I could of swore when I tried to give it throttle and crank it wouldn't turn over. I figured there was a switch that prevented this. Maybe I'm just dreaming. Also being my first boat it might not idle that low, it seems like it to me, but the way the drive engages I assume if can't idle very high.

 

[jrampey]

Re: 4.3 Mercruiser LX hard to start

You're right that it wont start with the throttle/gear shift lever advanced... (It would be starting while in gear) There should be a button that you can push at the base of the lever that disables the shift cable. Push that button and advance the throttle lever 25%. That will give you a "hi Idle" start. Still you should not have to do this regularly... Probably need some Carb work!

 

[Don S]

Re: 4.3 Mercruiser LX hard to start

Un-like cars with EFI engines, carbed engines require a little help to start. Here are the procedures from an owners manual.



4 Place control handle in NEUTRAL.

5 Push THROTTLE ONLY button and position throttle setting as follows:
COLD ENGINE - Move control/throttle lever to full throttle, then return to about 1/4 throttle. In extreme cold
it may be necessary to pump lever more than once.
WARM ENGINE - Move control/throttle lever to 1/4 throttle position.
FLOODED ENGINE - Move control/throttle lever to full throttle. Be prepared to decrease engine speed to
1000-1500 rpm as soon as engine starts.

6 Turn ignition key to START. Release key when engine starts and allow switch to return to RUN position.

7 Carbureted Engines - Move control/throttle lever back to decrease engine rpm to 1000-1500 rpm if necessary.

8 Check oil pressure gauge immediately after engine starts. If oil pressure is not within specified range (see
SPECIFICATIONS), stop engine immediately and determine cause.

9 If engine is cold, run engine for 1 or 2 minutes at fast idle (1000-1500 rpm).

 

[skeffington]

Re: 4.3 Mercruiser LX hard to start

Well I'll be, there is a button down there. I think they should maybe mark it.

I keep making myself look like an idiot on this message board, but the help is really appreciated.

 

[Don S]

Re: 4.3 Mercruiser LX hard to start

It's all in the owners manual that comes with the boat.

The best thing a new person could do when they buy their first boat is to find a reputable shop and have them go over the boat and explain to you all the systems and how they work.

 

[skeffington]

Re: 4.3 Mercruiser LX hard to start

I think I've done alright considering everything I've done to it so far. I've just never been around boats and I'm still fairly young and trying to figure everything out. I've never been one to read owners manuals but it probably wouldn't hurt. Even using the throttle only button it should start up better when It's been ran, but I assume that applies to what Chris was talking about.

But I am pleased at how well my boat does run being 18 years old. I owe a lot of thanks to this forum, it's really helped me out.