3.0L MCM 140 Boat will not start!

Hello all, Thank you in advance for your responses!

1986 16' Sea Ray MCM I/O 140 4cyl. 181 CID S/N A394995
MerCarb 2bbl (1 idle adjustment screw)
Block S/N 2770087 2 85
Alpha 1 Out Drive S?N A530190

It all started when the Boat sank last year after the shift cable bellow sprung a leak!

The boat was given to me after that! I removed head and got all water out of block and changed the oil. Boat sat for the winter in my garage and dried out real good.

Last week I replaced the head gasket, plugs, starter and new gas (the tank has a lot of water in it!)

Today i was ready to try and start it, Put the muffs on started the water and hit the key. It would not fire.
Checked fuel flow to the crab and all is good, but no fuel squirting into carb barrels.
Removed the carb opened her up and she was full of white residue. Looks like corrosion.
See pic
Cleaned carb up real good and cleaned the pump assembly as well.
Put carb back on and now I have a nice stream of fuel squirting into carb when I pump the throttle.

Now that all said and done! SHE WILL NOT STAY RUNNING!

I pump the throttle to get gas into carb, it fires idles for a few seconds and quits. Will not fire back up unless i pump the throttle again, then same thing.
I've tried pumping the throttle when it is idling but still dies. Like it only stays running until it burns off fuel i pump into carb.

Any ideas? Was thinking about pulling carb off again and checking the float level.

Free boat i cant complain. but here in Michigan the year is coming to an end. I would like to try and hit the water.

Once i get it running I have to tackle the bellows and going to replace the impeller while i have the out drive off.

Thanks again, and look forward to your responses.
CHOBES

Re: 3.0L MCM 140 Boat will not start!

Sounds to me like you need to clean the carb some more.

Get a rebuild kit and follow the instructions..

Make sure float level AND drop are correct.

Just checking float level isn't good enough...

Make sure to clean all the little passages and soak all the metal pieces in carb cleaner -- especially the cluster.....

If you can't soak the carb in carb cleaner, get a can of carb clear and squirt it through all the passages until they are clean -- especially the idle passage.

Set idle screw at 1 1/4 turns out

try to start engine

warm engine up

set idle screw for highest rpm, then adjust idle speed screw for desired idle

put boat in the water

warm up engine

set idle screw for highest rpm

set idle speed screw for desired idle.

enjoy

Re: 3.0L MCM 140 Boat will not start!

Didn't see it in your post, so just wanted to make sure you replaced ALL of the fluids, right?

Just replacing the engine oil ain't good enough. You need to replace the drive oil, the tilt oil, and the power steering fluid (this assumes you have power steering...)

Also, are you sure you got the tank completely dry before you put new gas in?

I'd add a fuel water separator just in case.....

Re: 3.0L MCM 140 Boat will not start!

Try running it off a separate tank. I would bet you have water and bad gas in it.

Re: 3.0L MCM 140 Boat will not start!

Thanks for the quick replies.

I am currently pulling gas from a gas can. Have not emptied the tank yet.
I will replace all fluids once i fix the bellows.
Just want to get it running first before i remove the Out drive.

Re: 3.0L MCM 140 Boat will not start!

Did you break the carb down more than in the picture? The accelerator pump is giving it enough fuel to fire but sounds like the carb is not supplying anything more.

Re: 3.0L MCM 140 Boat will not start!

thumpar said:

Did you break the carb down more than in the picture? The accelerator pump is giving it enough fuel to fire but sounds like the carb is not supplying anything more.

Click to expand...

No i did not. did think it could broken down much more! Pulled the pump out and cleaned it really good.
getting ready to pull carb off again and clean it better!

Re: 3.0L MCM 140 Boat will not start!

The other parts that can come out for cleaning are the important ones. Take the 3 philips head screws out and pull the venturi assm out. There are tiny holes and passages on that. Then there a check ball down there too. Pull the accelerator pump out ( the circle thing on the left. Take out the 2 jets and the round thing in the bottom of the bowl (think that is the high circuit). Use a wide blade screwdriver. Did you pick up a rebuild kit? If not they are pretty cheap and replace most of the warn parts and have the stick to measure the float level.

Re: 3.0L MCM 140 Boat will not start!

thumpar said:

The other parts that can come out for cleaning are the important ones. Take the 3 philips head screws out and pull the venturi assm out. There are tiny holes and passages on that. Then there a check ball down there too. Pull the accelerator pump out ( the circle thing on the left. Take out the 2 jets and the round thing in the bottom of the bowl (think that is the high circuit). Use a wide blade screwdriver. Did you pick up a rebuild kit? If not they are pretty cheap and replace most of the warn parts and have the stick to measure the float level.

Click to expand...

I will pick up the Rebuild kit tomorrow. Ahh was worried about pulling the 3 Phillips screws out! Will do that tonight.
Picking up a rebuild kit tomorrow as well as a starting solenoid (relay). Cant start with the key! been jumping the two terminals.

Re: 3.0L MCM 140 Boat will not start!

Thumper good call on the Venturi Assembly! Cleaned it up put, sprayed the carb really good with carb cleaner and she idles great!!! Still picking up a crab rebuild kit!

Thanks all!~ and i will be talking to you soon I'm sure when the outdrive comes off!. i'll start another post for that!

Picture is of Venturi assy! holes are plugged