Mercruiser has no spark but cranks good.

[imported_TheMan]

Re: Mercruiser has no spark but cranks good.

You can install a water/fuel separator pretty easily. You may have to get a length of USCG approved hose as your splice from the filter to the fuel pump likely will use up too much of the original hose length.

You can buy them from west marine, wally world, or online. Expect to pay around 30 dollars or so..

 

[WSR]

Re: Mercruiser has no spark but cranks good.

It seems like it keeps flooding and the only way to fire it up is to open it up all the way.Before I get to the Carb, I want to start with fresh gas.
I drained the tank of about 13 gallons into three 5 gallon jugs.The first jug had about 3 tablespoons of brown gunky water balling up on the bottom, the rest looked good.However it could be mixed with gas over 9 months old.I put 5 gallons in last week, oh well...I got gas for the lawnmower?
What would be the bet way to clean out the tank once I pump out the remaining gallon or so?

 

[Don S]

Re: Mercruiser has no spark but cranks good.

Check the clear (clear yellow) hose that goes from the fuel pump to the carb, is there any gas in it. You may have a defective fuel pump that is pumping raw gas into the carb (instead of the bilge like an automotive pump would) that would sure cause it to flood.
You could also have a leaky carb allowing gas into the intake when you shut it off.
Run it, shut it off then LOOK down the throat of the carb and see if there is fuel entering.

 

[WSR]

Re: Mercruiser has no spark but cranks good.

It is a new fuel pump and I do not see fuel in the sight hose, but I do see some fuel in the throat after I shut it off.

 

[chiefalen]

Re: Mercruiser has no spark but cranks good.

Ok bear with me whats the fuel pump giving, you should be between 4-6 psi.

You can clean that carb and make sure the float, is floating and not getting hung up.

Make sure the seat on the needle is good.

Make sure you get every little hole clean in that carb.

Spray it with carb cleaner and blow dry with compressed air.

Maybe the gunk is all over that carb.

Make sure all your filters are clean one in the fitting bye the carb. and if you have one in the fuel pump.

The one in the fuel pickup tube in the tank also.

And the anti-syphin valve good.

Or you can try to run it after you clean the carb on clean fuel in a external tank.

Than go after the filters, but the one in the fitting bye the carb must be cleaned.

 

[chiefalen]

Re: Mercruiser has no spark but cranks good.

To get all the crap outta the tank raise the bow as far as you can, take off the fuel pickup tube.

And stick a clear hose all the way to the back of the tank and suck it all out with a cheap electric fuel pump from a auto store.

But i would still run it on fresh fuel in a external clean tank. After you clean the carb.

 

[WSR]

Re: Mercruiser has no spark but cranks good.

I drained it dry with a manual hand pump, a rigged clear hose with a cut at an angle, had a helper fishing the hose from back to front, rinsed with fresh gas, sucked it dry again parked on a hill, then blew it out with a shop vac. Drained 15 gallons total.
I found a little water and saw some silt in the clear hose. I did not find to much in the fuel pump filter since its new. But I found a lot of the same stuff in the filter by the carb...cleaned that out and then went to town cleaning out the carb.

I spoke to a salty marine mechanic who works at this little mom and pop boat shop, (please support your MOM and POP shops!) and he swears by this stuff StarTron for my issue before I replace parts on the carb, he said run it for a few hours then clean and replace the filters.

New gas, clean carb, StarTron, did not replace a single part...

She fired up at the turn of the key!

I took her out for a test run last night and she ran better than ever. Took her through all the tests and no more issues! No stalling, No flooding, No hard starting.

Time to break out the wax...

Thank you to the IBoat Brain Trust for all of your help!